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1993
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SResearch Report Series No. 8 October 1993
Alabama Agricultural Experiement Station Auburn University
Lowell T. Frobish, Director Auburn University, Alabama

CONTENTS
GREENHOUSE CROPS .......................................................................................................................................................................................................................... 2
Evaluation of Ancymidol and Paclobutrazol for Height Control of Potted Tulips .................................................................................................. 2
Production and Postproduction of Brazilian Verbena as a Cut Flower .................................................................................................................... 3
Influence of Subirrigation on Postproduction Longevity of Poinsettias .................................................................................................................... 4
Performance Evaluation of Annual Bedding Plants ....................................................................................................................................................... 4
Perennial Plant Producers Profiled ....................................................................................................................................................................................... 6
Growth and Flowering of Zinnia and Marigold Treated with BAS111 ..................................................................................................................... 7
Production and Postproduction Performance of Sumagic-Treated Bedding Plants ............................................................................................... 8
Growth and Flowering of Triazole-Treated Zinnia and Marigold ........................................................................................................................... 11
Chemical Promotion of Axillary Shoot Development of Geranium Stock Plants .................................................................................................. 12
W OODY ORNAMENTALS .................................................................................................................................................................................................................... 15
Comparison of Two Root Control Techniques for the Urban Landscape ....................................... ....................................................................... 15
Influence of Subirrigation and Container Size on Growth of Two Tree Species ............. ................................................................. ..................... 16
Effects of Water Reservoirs on Growth of Container-Grown Pecan and Pear Trees ...................................... 16
Growth of Container-Grown Trees Transplanted from the Field or Grow-Bags ............. ........... ......................................................... ........... 17
Increasing Crotch Angles and Lateral Shoot Numbers of Bradford Pear with BA or Promalin.. ...... .. ....... ... ............ 22
Response of Established Landscape Plants to Uniconazole ......................... .................................................................................................... 23
Controlled Release Fertilizers Influence Container-Grown Azaleas ............................................ 25
CRF Type, Rate, and Placement Influence Growth of Container-Grown Ornamentals ...... ................................................................................ 26
INSECT, DISEASE, AND WEED CONTROL ..................................................................................................................................................................................... 27
Evaluation of Postemergence-Applied Herbicides on Ornamental Grass .................................................................................................................... 27
Evaluation of Preemergence-Applied Herbicides on Selected Hardy Ferns and Hosta ........... 28
Transmission of Phytophthora parasitica in Ebb and Flow Subirrigation System ............................................................... .................................... 30
Chemical Control of Azalea Lace Bug ......................................................................................................................................................................... 30
Fungicidal Control of Southern Blight on Aucuba ............................................................................................................... ...................................... 31
Use of Selected Pesticides and Pesticide Combinations Against Sweetpotato Whitefly on Container-Grown Ornamentals ............................. 32
Chemical Control of Two-spotted Spider Mite on Golden Euonymus .............................................................................................................................. 33
Chemical Control of Spot Anthracnose of Dogwood ................................................................................................................................................. 33
Dogwood Anthracnose on Dogwood in Alabama: Its Distribution and Severity ................................................................. ................ ..................... 34
E NVIRONMENTAL PROTECTION ......................................................................................................................................................................................................... 36
Nontarget Herbicide Losses from Application of Granular Ronstar to Container Nurseries .................................................... ........... ................. 36
Monitoring Irrigation at Container Nurseries ................................................................................................................... ......................................... 36
Agricultural Waste Products as Composted Soil Conditioners .......................................................... ............. ......................................................... 39
Consumers Favorably Evaluate a Growing Medium Containing Broiler Litter Compost......................................... .......................................... 40
FIRST PRINTING 3M, OCTOBER 1993
Information contained herein is available to all without regard to race, color, sex, or national origin.
ON THE COVER:
FeatherRed was one of the best varieties offlowering cabbage grown in Auburn University's All America Display Garden. See article on Page 4for more information.
GREENHOUSE CROPS
Evaluation of Ancymidol and Paclobutrazol for Height Control of Potted Tulips
C. Frederick Deneke and Gary J. Keever
Potted tulips often become excessively tall either during
greenhouse production or in postproduction environments. There-
fore, plant growth retardants are commonly used to control plant
height and reduce stem topple.
Foliar sprays and drenches are the most common methods of
application of plant growth regulators. However, to reduce appli-
cation costs and to improve the effectiveness of growth regulators,
alternative application methods have been investigated, including
tablets, gels, encapsulation, granular formulations, and impreg-
nating clay pots. A study was conducted to determine if an
ancymidol drench or paclobutrazol applied as a drench or impreg-
nated in a fertilizer spike could effectively control height of tulips.
Results showed that plants receiving 0.25 or one milligram of
paclobutrazol per five-inch-diameter pot exhibited acceptable
growth with the drench and spike treatments. A 0.25-milligram
ancymidol drench also provided acceptable mature plant heights.
METHODS
On Dec. 21, 1987, five bulbs (at least 4.5-inch circumference)
of Kees Nelis tulips were potted per 0.8-liter (five-inch diameter)
container using a commercial peat moss and perlite growing
medium (Pro-Mix BX, Premier Brands, Stamford, Conn.) and
placed in a dark cooler at 48
0
F. When root growth out of the
bottom of the pot was evident four weeks later, temperature was
decreased to 41OF until the emerging shoots were about 1.5 inches
long. Plants were moved to a double polyethylene greenhouse
maintained at 64
0
F during the day and 57
0
F at night.
Treatments were applied one day after the plants were moved.
Rates of growth retardant ranged from 0.06-1.00 milligram per
pot for both the drench and spike applications of paclobutrazol. A
drench of 0.25 milligram of active ingredient ancymidol per pot
was also applied. Drenches were applied using a volume of 75
milliliters per pot. Spikes were identical to Jobe Fertilizer Spikes
(10-10-4, Weatherly Consumer Products, Lexington, Ky.) except
that the manufacturer incorporated paclobutrazol. One spike was
positioned vertically just below the surface of the growing me-
dium in the center of the pot. Spikes used for the control did not
have paclobutrazol incorporated.
Plants were fertilized weekly, alternating 200 parts per mil-
lion (ppm) nitrogen (N) from 20-20-20 and 375 ppm N from
calcium nitrate. When flowers first showed color, plant heights
were measured. When flowers were fully opened, plant heights
and flower diameters were measured.
RESULTS
Time to maturity (time from entering the greenhouse to
flowers fully opened) for Kees Nelis tulips was about 21 days
regardless of treatment. Heights at first flower color and at
maturity were reduced as the concentration of paclobutrazol
increased with both methods (see table; Photo 1, Page 18).
Paclobutrazol application method did not significantly affect any
of the measured variables. Treatments had no effect on flower
diameter or uniformity of plants within a pot.
Heights at first flower color and at maturity for ancymidol-
treated plants were less than those of either plants receiving the
lowest rate of paclobutrazol applied as a drench or spike, or of
control plants.
Because height for potted plants should be no greater than two
times the diameter of the pot, the maximum acceptable height for
plants in a five-inch diameter pot is 10 inches. Therefore, plants
receiving a spike or drench of 0.25 or one milligram of active
ingredient paclobutrazol per pot or a drench of 0.25 milligram of
active ingredient ancymidol per pot had acceptable heights at
maturity. In contrast, control plants were 11 inches tall at matu-
rity.
Reduction in Height of Tulips with an Ancymidol Drench or Increasing
Rates of Paclobutrazol Applied as a Drench or Impregnated Spike
Treatment Plant height at:
Flower color Maturity'
Paclobutrazol
2
Drench
0.06 ................. ... .... .................. 9.1 11.4
0.25 ... .................................. 8.1 10.0
1.00 ............................ ........ .... 6.4 9.4
Spike
0.06 ................................ .................. 8.6 10.5
0.25 ................................ .................. 7.9 9.7
1.00 .............................. ....................... 7.5 9.4
C ontrol ................................................... 8.5 10.9
Ancymidol
2
Drench
0.25 ................................ .................. 7.6 9.4
1
When flowers were fully opened. Plant height was measured in inches.
2
Treatments measured in milligrams per pot. One gram (g) is .035 ounce. 
One
milligram (mg) is .001 g.
Deneke is former Assistant Professor and Keever is Professor of
Horticulture.
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Production and Postproduction of Brazilian Verbena as a Cut Flower
Catherine Chege, C. Frederick Deneke, and Bridget K. Behe
Wholesale value of total production of standard cut flowers -
- such as roses, carnations, chrysanthemums, and gladioli -- has
continued to decline over recent years while total American
consumption, importation of cut flowers, and wholesale value of
specialty cut flowers have increased. To reduce risks and maxi-
mize profits in this ever-changing market, it is necessary to
diversify cut flower production. One way of doing this is by
growing new varieties of cut flowers.
Brazilian verbena (Verbena bonariensis) can be grown as an
annual but is a perennial in central and southern Alabama. Its long
stems and long-lasting flowers potentially make it a good cut
flower. A study was conducted to determine the effect of varying
daylength (photoperiodism) on flowering and the effect of stage
of development at harvest on vase life of Brazilian verbena as a cut
flower.
Results show that Brazilian verbena should be grown under
long days for earlier flowering (see Photo 2, Page 18). Harvesting
should be done before all of the flower clusters are opened, but
after the buds show color for the best quality of cut flowers.
METHOD
In the photoperiod study, Verbena seeds were planted in flats
on Sept. 18, 1992, in Pro-Mix media. Seeds were germinated in a
greenhouse with 770F day and 64
0
F night temperatures and ex-
posed to either long days or short days. All the plants were covered
with black cloth from 5 p.m. to 8 a.m. Long days were provided
by night-break lighting (10 p.m. to 2 a.m.) using incandescent
lamps. Plants under short days were moved two or four weeks
after seeding to long days for the remainder of the experiment.
Likewise, plants under long days were moved after two or four
weeks to short days. Other plants were grown under constant long
or short days. Fertilization initially was two times per week with
100 parts per million (ppm) N using 15-16-17 fertilizer. Fertiliza-
tion was increased to three times weekly after transplanting,
which was done on Oct. 21, 1992.
In the stage of development at harvest study, verbena seeds
were planted in flats on Sept. 18, 1992, in Pro-Mix medium. The
seeds were germinated as described with the photoperiod study.
Plants were exposed to long days only. Seedlings were trans-
planted on Oct. 18, 1992, and grown in Fafard No. 2 medium.
Fertilization was as described previously. On Feb. 25, 1993,
flowers were harvested at bud-colored stage, two-to-five open-
floret stage, and 100% open stage of the first and second pair of
inflorescences (flower clusters).
The flowers were then transferred to a simulated consumer
environment maintained at 70
0
F, 12-hour photoperiod, and 60
footcandles of light for postproduction evaluation. They were
pulsed with silver thiosulfate for 30 minutes and then placed in
deionized water. Color change of the oldest (peripheral) florets
from violet-blue to white, bent neck, and weight of cut flowers
taken at the same time each day were used to determine the vase
life.
RESULTS
Verbena plants grew faster under long days, which resulted in
bud formation and flowering. When plants received less than nine
hours of light daily, they did not flower. Alternating long or short
days had no effect on the flowering date and flower quality.
Therefore, long days could be initiated four weeks after seeding
instead of at germination to reduce lighting costs. Only one
inflorescence (flower cluster) formed per plant. Plants that re-
ceived short days had more branches. The inflorescence length
was good for use as a cut flower.
Flowers harvested at the two-to-five floret-open stage lasted
longer than those harvested at bud-colored stage or when 100% of
inflorescences were opened. Flowers harvested at the bud-colored
stage did not open well and had a faded color. Although flowers
harvested at the 100% open stage of the first and second pair of
inflorescences had more open flowers at senescence, they suf-
fered from bent neck and lasted only for a short time.
Chege is Graduate Student, Deneke is former Assistant Professor, and
Behe is Assistant Professor of Horticulture.
Effects of Daylength on Flowering of Brazilian Verbena
Treatment Duration
1  
Inflorescence/plant
2  
Branch/plant Inflorescence length
3
To visible buds To flowering
days days no. no. cm
Constant LD
4 
........
.. . . . . . . . .
... 77 87 1.0 2.0 155.0
2 weeks SD
5, 
then LD ....... 78 87 1.0 1.3 152.0
4 weeks SD, then LD ........ 77 87 1.0 2.0 158.3
Constant SD
6 
.........
. . . . . . . . . . .  
- - - 3.8
2 weeks LD, then SD........ - - - 5.2
4 weeks LD, then SD ........ - - - 4.7
'Time from seeding (photoperiod treatment).
2
Flower cluster 
peper plant.
3
One centimeter (cm) is .3937 
inch.
4
LD = long days (night-break lighting 
10 p.m. - 2 p.m.).
5
SD = short days (no night-break 
lighting).
6
Plants did not form 
buds.
Influence of Subirrigation on Postproduction Longevity of Poinsettias
C. Frederick Deneke, Bridget K. Behe, and John W. Olive
Water quality concerns affect the content of effluent that can
be legally discharged from agricultural businesses. Ebb and flow
production technology is a closed subirrigation system that pre-
vents water used in irrigating greenhouse crops from being rou-
tinely discharged into the environment.
This technology has been adopted in Europe, but few Ameri-
can growers use it. One concern is that subirrigation may reduce
the postproduction longevity of plants if excess fertilizer salts are
not leached. Previous research indicated that subirrigated poinset-
tias had lower plant grade than those that were hand irrigated.
However, media soluble salts were not closely monitored during
production.
A followup study was conducted to determine the influence
of hand irrigation or subirrigation on the postproduction quality of
Supjibi poinsettia with regular monitoring of media soluble salts.
Irrigation method was shown to have minimal impact on overall
plant grade and that postproduction quality of subirrigated plants
can be at least as good as that produced by hand irrigation if media
soluble salts are monitored during production.
METHODS
On Aug. 26, 1991, cuttings of Supjibi were stuck into six-inch
azalea pots using a commercial soilless growing medium
(Metromix 360, Grace-Sierra). Cuttings were allowed to root
under intermittent mist for 14 days. Twelve plants per treatment
were fertilized at each irrigation beginning Sept. 9 using equal
parts (by volume) of calcium nitrate and 20-10-20 (Peter's Peat
Lite, Grace-Sierra). Fertilizer concentration initially was 200
parts per million (ppm) nitrogen (N); from Nov. 11 to Dec. 9, 100
ppm was used. Irrigation method was either hand or subirrigation.
Hand irrigation consisted of watering plants with a hose until
water began to drip from the bottoms of containers. Subirrigation
consisted of flooding watertight benches to a depth of about 3/4
inch for 15 minutes. Media leachates were taken at two-week
intervals to determine soluble salts. On Dec. 9, growth was
evaluated, and plants were moved to a simulated consumer envi-
ronment maintained at 70OF and about 75 foot candles of light
provide by cool-white fluorescent lamps from 6 a.m. to 6 p.m. (see
Photo 3, Page 18).
RESULTS
Media soluble salts for hand-irrigated plants on the first
sampling date (Oct. 21) were significantly greater than for
subirrigated plants. On the three subsequent samplings, soluble
salts were similar regardless of irrigation method. At the time
plants entered the postproduction environment, subirrigated plants
had greater numbers of bracts (small leaves at the base of flowers
or stalks), cyathia (small yellow flowers above bracts), and
inflorescences (flower clusters). Plant grade, growth, and the
number of leaves were not influenced by irrigation method.
After three weeks in the postproduction environment, leaf
drop was greater for subirrigated plants. Irrigation method did not
influence bract drop, cyathium drop, or plant grade (see table).
From week four to five in the postproduction environment, irriga-
tion method had little influence on any measured variable (data
not shown).
Deneke is former Assistant Professor and Behe is Assistant Professors of
Horticulture; Olive is Superintendent of the Ornamental Horticulture Substation.
Plant Grade, and Leaf, Bract, and Cyathium Drop of Supjibi Poinsettia after Three or Four Weeks in a Postproduction Environment
Irrigation method Three Weeks Four Weeks
Grade' Bract Drop
2,3  
Leaf Drop
2  
Cyathium Drop
2,4  
Grade' Bract Drop
2 ,3  
Leaf Drop
2  
Cyathium Drop
2
,
4
Hand ......................................... 3.8 2.3 8.5 67.2 2.8 15.0 22.5 100.0
Sub- .......................................... 3.9 3.7 17.1 32.4 3.2 11.2 26.2 89.9
'Rated on a scale from 1 (poor) to 5 (excellent). 3Bracts are small leaves that grow at the base of flowers or stalks.
2
Percentages are cumulative leaf or bract drop relative to total number 
present at Week 0. 
4
Cyathia are small yellow flowers above the bracts.
Performance Evaluation of Annual Bedding Plants
C. Frederick Deneke, Bridget K. Behe, and Jim Bannon
From November 1991 to March 1992, about 130 entries of
cool-season bedding plants were evaluated at the Auburn Univer-
sity greenhouse facilities and E.V. Research Center in Tallassee,
an official All-America Selections Display Garden.
Trial gardens are useful for evaluating the performance of
new and established plant varieties, but results cannot be viewed
as strict recommendations. Weather, hardiness zone, soil, expo-
sure, and cultural practices can greatly affect the growth of plants.
Comparison of results from multiple trial sites will increase the
reliability of recommendations. (See Photo 4, Page 18.)
METHODS
Seeds were germinated and grown to transplant by commer-
cial growers, who donated their services. Beds in full sun were
tilled, covered with a layer of plastic, and fumigated with methyl
bromide two weeks before planting. Soil pH was adjusted to about
6.5. Twelve plants per variety were spaced nine inches on center
in double rows. Plants were drip irrigated and fertilized as needed.
RESULTS
Viola x wittrockiana (pansy)
Generally, no cool season bedding plant can compare with
pansies for the diversity of color, duration of flowering, and
tolerance to cold and heat. Although all 37 cultivars of pansies
flowered, none was spectacular for undetermined reasons. The
following cultivars were noticeably superior:
Universal Purple -- slow to start, but good flowering after
mid-January;
Maxim Red Yellow -- slow to start, but good flowering after
early January;
Melody Yellow Blotch -- very slow to start, but good flower-
ing during March; one of only two entries that completely filled
area between plants;
Universal Deep Yellow -- good flowering from late Decem-
ber to early February, then declined;
Universal White -- quick to flower after planting and consis-
tently good thereafter;
Roc White -- almost as good as Universal White; flowering
good after mid-December;
Melody White Blotch -- slower to establish but good flower-
ing after late-December, peaking in mid-March (Photo 5, Page
18); completely filled the area between plants; and
Roc Mix -- slow to establish but uniform and good flowering
after late December. The good performance of the Rocs was
surprising considering that they were selected primarily for the
North.
Brassica oleracea (flowering cabbage or kale).
This ornamental vegetable can provide foliage color through-
out winter, but its landscape usefulness is limited by flowering
(bolting), which can occur in January or February. Also, these
plants usually are not as cold tolerant as pansies; plants frequently
decline because of leaf browning or rot. Fifteen entries were
evaluated. Generally, kale is more cold tolerant than cabbage, and
red varieties are more cold tolerant than white or pink. Notable
varieties included:
Feather Red -- latest to bolt and minimal cold damage,
making it one of the best (see cover); color faded by mid-March;
Color Up Red -- began to bolt by early March, but was the
only red cultivar to retain deep, red color until late March when the
evaluation was terminated; one of the best-looking entries;
Nagoya Red, Osaka Red -- impressive in January and Febru-
ary, but began to bolt in late February, followed by fading of the
leaves and flowering stems;
Feather White -- the only white cultivar that did not have
significant cold damage (Photo 6, Page 18) and the last to bolt,
making it one of the best selections; also one of the best-looking
entries. Other white cultivars began to bolt in late February, about
three weeks before Feather White; and
Color Up Pink -- did not bolt until late March, but its
landscape usefulness was limited by cold damage; color always
appeared faded or bleached.
Dianthus chinensis (china pinks)
Generally, china pinks can overwinter in central and southern
Alabama and produce great quantities of flowers by early spring.
Flowering in this evaluation generally was minimal until March.
However, vegetative growth of most, especially the Charms,
would add to an otherwise barren winter landscape. Charms --
Coral, Crimson, Pink, White -- were vegetatively attractive be-
cause of their uniform mounding growth and blue-green to green
foliage. Little cold damage was noted on any of the 18 varieties.
January and steadily increased after mid-February; the only stand-
out entry when considering earliness and duration of flowering;
Princess Salmon -- better than Charm Coral or Charm Pink,
but none of the pink shades flowered well;
Princess Purple -- flowering marginal until early March;
appeared more red than purple;
Telstar Purple Picotee --flowering marginal until early March;
Princess Crimson and Princess Scarlet-- flowering was good
after early February;
Charm Scarlet, Telstar Scarlet, and Telstar Crimson -- had
begun to shine by early March; and
Telstar White and Princess White --began to flower well after
early March, but none of the whites were exceptional.
Antirrhinum majus (snapdragon)
Similar to China pinks, snapdragons survive mild winters and
flower well during early spring. However, many succumbed to the
sudden cold temperatures (low 200 F) during early November.
Twenty-one entries of snapdragons were evaluated. The perfor-
mance of the Liberty series (Bronze, Cherry, Crimson, Lavender,
Light Pink, Mix, Rose Pink, Scarlet, Yellow, and White) was
surprisingly poor since all either died during November and
December or had minimal flowering. Floral Carpet Red did not
fare much better. However, Liberty snapdragons have performed
well in other trial gardens, including the University of Georgia.
Notable cultivars included:
Floral Showers Scarlet -- flowering good after early March
(Photo 7, Page 18);
Floral Carpet Rose was -- fair flowering;
Floral Carpet Yellow -- good flowering, noticeably better
than Floral Showers Yellow; and
Floral Showers White -- flowering good by mid-March;
better than the marginal Floral Carpet White.
Deneke and Behe are Assistant Professors of Horticulture; Bannon is
Director of the E.V. Smith Research Center.
Flowering throughout the evaluation was minimal, except with
Charm Scarlet. Notable cultivars included:
Telstar Picotee -- red flowering good beginning in early
Perennial Plant Producers Profiled
Bridget K. Behe and Lisa M. Beckett
The U.S. ornamental plant industry is relatively large and
growing, with wholesale revenues of slightly more than $4 billion.
Herbaceous perennials comprise what is believed to be a signifi-
cant part of the industry, yet statistics to document production
numbers and annual growth of this segment are sparse. The
Census of Horticultural Specialties lumped perennials into the
category of bedding and garden plants and reported their whole-
sale value at $21 million. However, estimates show that the value
of the herbaceous perennial plant industry was between $78 to
$150 million. The industry appears to be under-valued based on
production statistics.
Owners and managers have been directing perennial plant
businesses through at least a decade of growth with little informa-
tion about the size and scope of the industry. An AAES study was
conducted to establish a base of information about perennial plant
producers. More information about these firms may help profes-
sionals better understand one facet of this complex industry.
According to study results, perennial plant businesses still
appear to be relatively small, but sophisticated businesses man-
aged by highly educated and experienced professionals. Firms
produced an average of 30 perennial plant genera, which must
require them to have a broad base of production and propagation
knowledge. When examining the businesses by the product mix
they sell, there are some differences meaning that both newer and
more established firms have incorporated perennial plants into
their product mix.
METHODS
The AU Horticulture Department and Perennial Plant Asso-
ciation collaborated to develop a survey of herbaceous perennial
plant producers. Questionnaires were mailed to 439 members of
the Perennial Plant Association classified as "producer/grower"
on July 1 and again on July 23 if no response was received. Of
those, 150 firms returned forms for a 34% response rate.
RESULTS
Fifty percent of the firms were sole proprietorships, 13%
were partnerships, and 34% were corporations. The mean age of
participating businesses was 17 years, the median (middle value)
was nine years, and the mode (most frequent) was five years. The
mean total sales for the perennial plant businesses in 1989 was in
the category of $100,000 to $249,000, the median was in the
category of $250,000 to $499,000, and the mode was $50,000 to
$99,999. Mean wholesale sales were $302,000 and mean retail
sales were $63,585. While many were smaller and younger
businesses, there were several larger, established firms that in-
creased the averages.
Seventy-one perennial plant genera were listed on the survey
form. At least some of the participating firms grew each listed
genus. Coreopsis (Photo 8, Page 19) was produced by the largest
percentage (66%), followed by Acquilegia (64%), Achillea (62%),
Chrysanthemum (excluding garden chrysanthemum) (62%),
Echinacea (61%), Hosta (61%), and Dianthus (61%). The mean
number of genera produced by each firm was 30.
To see if there were any differences based on how important
Sperennial plants were to the company's sales revenues, each firm
was classified by the percentage of the firm's total sales that was
accounted for by perennial plants as either (1) totally perennials
(100%), (2) primarily perennials (50% to 99%), or (3) secondarily
perennials (49% or less).
There was a significant difference in the number of years in
operation and the percentage of sales that perennial plants gener-
ated (see table). Firms that produced only perennials were in
operation an average of 12 years, while primarily perennial firms
were in operation an average of 15 years. Firms classified as
secondarily perennial producers were in operation an average of
22 years. Businesses that relied totally on perennial plants were
relatively young compared with more established firms that
apparently added the perennial plant line to broaden already
existing product lines.
There was no significant difference in the number of peren-
nial species grown by firms classified as totally, primarily, or
secondarily perennials. Each group produced, on the average,
near 30 perennial genera.
The difference in sales at the wholesale level for these three
types of firms was examined and no significant difference was
found. The variation in sales within each type of perennial busi-
ness classification was too large to see any trends in sales.
There was a distinct difference in the product mix sold by the
three types of firms. Businesses that sold perennials only had no
sales of annual plants, woody ornamentals, hardwoods, or chemi-
cals. Businesses that sold perennials primarily or secondarily did
sell significantly higher percentages of these product lines (see
table).
Comparisons of Perennial Plant Firms by Product Mix Sold
Variable Perennial Product Mix'
Secondarily Primarily Totally
Years in operation..........22 15 12
No. species grown..........27 33 37
Wholesale sales, 1989 dol.
2 
.332M 173M 199M
Wholesale units sold ............. 148M 212M 149M
Pct. annuals sold...........19 8 0
Pct. woody plants sold ............... 32 6 0
Pct. hardwoods sold.......... 3 >1 0
Pct. chemicals sold ............... 2 >1 0
'Secondarily - 1-49%; Primarily = 50-99%; Totally = 100%.
2= thousands.
Behe is Assistant Professor and Beckett is Research Associate of
Horticulture.
LIIV~~~ IJV llllllr3 I~LUIII~~L IVllllr3 IV1 CL J'T /V IL~VVII~~ ICCL~
Growth and Flowering of Zinnia and Marigold Treated with BAS111
Chia-Lun Chen, Gary J. Keever, and C. Fred Deneke
Plant growth regulators (PGRs) are commonly used in the
production of bedding plants to control growth and improve plant
appearance and other factors. Once transplanted into the land-
scape, plants are expected to grow out of the treatments, but the
new triazole compounds, such as paclobutrazol and uniconazole,
are more active in plants for longer periods of time than daminozide
or ancymidol.
BAS 111 is a triazole derivative that has been tested as a PGR
for fruit trees. Activity and persistence of BAS 111 were less than
those of uniconazole or paclobutrazol when applied to apple
seedlings by injection or soil drench or when applied to zinnia and
marigold by foliar spray. No information has been published on
the activity and persistence of BAS111 on bedding plants. An
experiment was conducted to evaluate the influences of BAS 111
dosage and application method (foliar versus drench) on growth
and flowering of zinnia and marigold during greenhouse produc-
tion.
Acceptable height control was obtained with BAS 111 when
zinnia was treated with a single foliar application of 500 parts per
million (ppm) or a medium drench of two or four milligrams (mg)
of active ingredient per pot. Desirable height of marigold was
obtained with a drench application of two milligrams per pot, but
not with any concentration of foliar spray.
METHODS
Seeds of Sunrise Yellow zinnia were direct-sown on May 15,
1990, in one-quart standard pots using a growing medium of 7:1
pine bark:sand (by volume) amended with six pounds dolomitic
limestone, 1.5 pounds Micromax micronutrient fertilizer, and 12
pounds Osmocote 14-14-14 per cubic yard. Seeds of Inca Yellow
marigold were sown in flats of Metro-mix 360 on July 26, 1990.
Marigold seedlings with one pair of true leaves were transplanted
on Aug. 3, 1990, into 0.8-quart azalea pots of the same growth
medium used with zinnia. After transplanting, seedlings were
fertilized weekly with 300 ppm nitrogen (N) from Peters 20-20-
20. Plants were grown in a polyethylene-covered greenhouse with
a ventilation setpoint of 80
0
F.
BAS 111 was applied to zinnia on May 31 and to marigold on
Aug. 16 when the second pair of true leaves had formed. Treat-
ments to zinnia included foliar sprays ranging from 500-2,000
ppm, as well as drenches ranging from two to 10 milligrams active
ingredient per pot in a volume of one ounce per container.
Treatments to marigold included foliar sprays ranging from 75-
300 ppm and drenches ranging from two to eight milligrams of
active ingredient per pot in a volume of one ounce per container.
Treatments included an untreated control with each species.
Plant height from the growing medium surface to the upper-
most growing point was measured when treatments were applied
and each week thereafter until flowering. When the first inflores-
cence (flower cluster) was fully opened, the growth index, height
from the surface of the growth medium to the top of the first
formed inflorescence, diameter of the first inflorescence, pe-
duncle (stalk) length of the first inflorescence, number of inflores-
cence buds (bud diameter greater than 0.4 inch), and number of
days to flower were determined.
RESULTS
Drench and spray applications of BAS 111 were effective in
retarding plant height and growth index of zinnia (Table 1).
Beginning one week after treatment and continuing through
flowering, the height suppression increased as BAS111 concen-
tration increased for both application methods. Compared to
control plants one week after treatment, growth decrease ranged
from 16-19% with a foliar spray and from 15-27% with a drench.
By the third week, heights of plants were reduced from 43-70% by
the 500 ppm and 2,000 ppm foliar spray applications, respec-
tively; and 27-61% by the two-milligram and 10-milligram drench
applications, respectively. Height suppression was severe and
unacceptable with 1,500 and 2,000 ppm foliar sprays, and with
eight- and 10-milligram drench concentrations.
Generally, the most desirable height and appearance were
obtained with a 500 ppm foliar spray or a two- or four-milligram
drench application. BAS 111 resulted in 23-46% reductions in
growth index by the 500 ppm and 2,000 ppm foliar spray applica-
tions, respectively; and 3-50% reductions by the two-milligram
and 10-milligram drench applications, respectively.
Table 1. Influence of BAS111 Application Method and Concentration on Height, Growth Index, and Flowering Characteristics of Sunrise Yellow Zinnia
Treatment Plant height
1 ,
2 Growth Days Peduncle Height Inflorescence Inflorescence
Week 1 Week 2 Week 3 index
3  
to flower length
4  
diameter
5  
no.
cm cm cm cm cm cm cm
Control
0 ............................ 13.8 26.7 47.6 45.1 25.5 8.7 65.9 6.9 4.1
Spray
6
500 .......................... 11.6 17.1 27.0 34.6 27.7 9.0 44.9 6.3 3.2
1,000 ....................... 12.2 17.2 24.8 31.0 27.9 6.9 34.5 5.7 5.3
1,500 ....................... 11.6 13.9 17.4 24.6 30.2 6.8 29.0 4.7 3.7
2,000 ....................... 11.2 13.4 14.4 24.5 33.2 5.2 28.3 5.2 3.5
Drench
7
2 ............................... 11.7 19.5 34.8 43.9 27.9 9.5 56.0 7.0 4.0
4 ............................... 10.8 16.3 27.2 33.1 26.0 8.6 43.0 6.1 3.8
6 ............................... 10.7 15.4 25.0 29.2 25.9 6.4 36.8 5.8 3.7
8 ............................... 11.5 16.1 21.6 28.1 26.7 7.7 36.3 5.4 3.4
10 ............................ 10.1 13.7 18.6 22.7 27.1 6.5 28.2 5.5 3.1
'Data collected weekly beginnining one week after treatment. 
4
Peduncle (stalk).
2
One centimeter (cm) equals .3937 inch. 5Inflorescence 
(flower cluster).
3Growth index = (height + width
1 
+ width
2
)/3. Width, was at the widest point, and 6Measured in parts per million (ppm).
width
2 
was perpendicular to width,. Growth index was determined when the first 
7
Measured in milligrams (mg) of active ingredient per pot. One mg is .001 gram;
inflorescence was fully opened. one gram is .035 ounce.
Inflorescence heights of plants treated with BAS111 also
decreased with increasing concentrations, from 32-57% with 500
ppm and 2,000 ppm foliar spray applications, respectively; and
from 15-57% with the two-milligram and 10-milligram drench
applications.
Time to flower of zinnia increased with increasing concentra-
tions of foliar-applied BAS111; the delay in flowering ranged
from two to eight days. Drench application had no effect on time
to flower. Conversely, peduncle length was not affected by spray
application, but decreased with an increase in drench concentra-
tion. Inflorescence diameter decreased with increasing concentra-
tions of both foliar spray (maximum decrease of 25%) and drench
application (maximum of 20%). Inflorescence numbers were not
affected by BAS 111 concentration or method of application.
Several plant measurements were less when plants received
a foliar spray compared to drench application, including height
two weeks after treatment (8.3 versus 9.8 inches), growth index
(11.4 versus 12.2 inches), and inflorescence height (13.5 versus
15.8 inches) and diameter (2.2 versus 2.4 inches). Only time to
flower was less with the drench application. Greater activity of
spray application relative to drench application may reflect a
reduced activity of triazole retardants induced by pine bark in the
growth medium or more total active ingredient being applied with
a foliar application. About 0.2 ounce of spray was applied to the
point of runoff to each plant. This volume of a 2,000 ppm solution
contains 14 milligrams of active ingredient, four milligrams more
than the highest drench concentration. A portion of the foliar spray
may have been applied directly to the medium surface or reached
the surface as runoff. Solution reaching media by these methods
have been shown to increase the efficiency of a PGR.
Heights of marigold receiving a drench application ofBAS 111
decreased with increasing concentration of BAS111 beginning
one week after treatment and continuing until flowering (Table 2).
The decrease in height relative to that of control plants was 40%
and 43% one week after treatment and 15% and 44% at six weeks
after treatment with the lowest and highest drench concentrations,
respectively. Height of the first formed inflorescence was 12-20%
less than that of control plants. Growth suppression was excessive
and unacceptable with four-, six-, and eight-milligram drench
applications. Height was initially retarded by foliar application of
BAS111 but the effect dissipated over time. Plants were 35%
shorter than control plants one week after treatment and 13-26%
shorter two weeks after treatment. From four weeks after treat-
ment until flowering, there was no consistent retardation of plant
height with foliar application.
Growth index at flowering and inflorescence diameter de-
creased with increasing concentration of BAS 111, regardless of
method of application. The decrease in growth index with spray
application indicates that plants were not as wide as control plants
since heights were similar. Inflorescence diameter was decreased
11-23% and 17-19% with foliar spray and drench applications,
respectively. BAS 111 did not influence time to flower, peduncle
length, or inflorescence number.
Chen is former Graduate Student, Keever is Professor, and Deneke is
former Assistant Professor of Horticulture.
Table 2. Influence of BAS111 Application Method and Concentration on Flowering Characteristics of Inca Yellow Marigold
Treatment Days to flower Peduncle length
1,2  
Inflorescence height
3  
Inflorescence diameter Inflorescence no.
cm cm cm
Control
0 ....................................... 25.5 8.7 65.9 6.9 4.1
Spray
4
500 .................................... 27.7 9.0 44.9 6.3 3.2
1,000 ................................. 27.9 6.9 34.5 5.7 5.3
1,500 ................................ . 30.2 6.8 29.0 4.7 .3.7
2,000 ................................. 33.2 5.2 28.3 5.2 3.5
Drench
5
2 ........................................ 27.9 9.5 56.0 7.0 4.0
4 ........................................ 26.0 8.6 43.0 6.1 3.8
6 ........................................ 25.9 6.4 36.8 5.8 3.7
8 ........................................ 26.7 7.7 36.3 5.4 3.4
10 ...................................... 27.1 6.5 28.2 5.5 3.1
'One centimeter (cm) equals .3937 inch. 
4
Measured in parts per million (ppm).
2
Peduncle (stalk). 
5
Measured in milligrams (mg) of active ingredient per pot. One mg is .001 gram;
3
Inflorescence (flower cluster). 
one gram is .035 ounce.
Production and Postproduction Performance of Sumagic-Treated Bedding Plants
Gary J. Keever and William J. Foster
Triazole-based plant growth inhibitors, which include Sumagic
and Bonzi, are active on many bedding plants, including those not
affected by other commercially available growth retardants. How-
ever, these compounds are active in low dosages and are persis-
tent, which could cause undesirable growth inhibition after plants
are transplanted into the landscape.
Limited information is available on postproduction growth
and performance of triazole-treated bedding plants. A study was
conducted to determine the influence of various dosages of
Sumagic on production and post-production performance of sev-
eral bedding plant species.
Results show that Sumagic is effective in suppressing inter-
node elongation and increasing a plant's tolerance to water stress,
both of which should enhance and extend marketability. How-
ever, optimum rates are specific to a given species. Growth
suppression may continue after plants are transplanted into the
landscape, but plants may exhibit an accelerated growth rate after
the growth-retarding effect dissipates. Sumagic applied at too
high a concentration will suppress growth excessively and delay
flowering. The effects may persist for five or more weeks after
plants are transplanted into the landscape, depending upon the
plant species and the concentration of Sumagic applied.
METHODS
Uniform 0.6-inch plugs (288 cells per tray) of Ringo Deep
Scarlet geranium, Inca Orange marigold, Blue Shades pansy,
Zenith New Guinea impatiens, and Victoria Blue salvia were
transplanted on Jan. 31, 1989, into pint containers of a peat moss
and perlite (1:1, by volume) growth medium. Plants were main-
tained in a glasshouse with heat and ventilation set points of 60'F
and 85'F, respectively, and fertilized weekly with 500 parts per
million (ppm) nitrogen from 20-10-20 Peter's Peatlite Special.
The following treatments were applied on Feb. 16, 1989,
when geranium, marigold, pansy, impatiens, and salvia were an
average of 1.5, 3.7, 1.8, 3.7, and 1.1 inches tall, respectively.
Treatments were: single Sumagic sprays of 0-30 ppm (see tables)
or a single daminozide spray of 5,000 ppm. Sprays were applied
in a volume of two quarts per 100 square feet using a hand-held
sprayer to uniformly wet foliage and stems. Ambient temperature
was 84?F with 63% relative humidity at time of application.
Plant heights, growth indices, and a foliar color rating were
determined four to eight weeks after treatment. Specific dates of
data collection were based upon growth and developmental rates
of the individual species and are given in the tables. When these
data were collected, flowers or inflorescences were counted and
peduncle (stalk) lengths of pansy were measured.
To determine treatment effects on water stress tolerance, five
plants of each species-treatment combination, except geranium,
were placed on a greenhouse bench on April 12 and thoroughly
watered. Thereafter, water was withheld from the plants, and time
to first signs of wilting was noted by monitoring plants every 30
minutes from 8 a.m. until 6 p.m. Hours between 6 p.m. and 8 a.m.
were not counted in determining time to wilting because loss of
moisture during this period was considered insignificant. Water
was withheld from geraniums beginning on April 24. Following
wilting of all plants of a species, shoots were cut at the growth
medium surface, dried at 120
0
F for 72 hours, and weighed.
On April 12 (impatiens, salvia), and April 26 (geranium), five
plants from each treatment were planted into the landscape to
evaluate post-production growth. Pansies were not transplanted
because of their typically poor performance in the south Alabama
landscape after early April. Marigolds were not planted into the
landscape because of their relatively minor responses to growth
retardant treatments. The ground bed consisted of a sandy-loam
soil with two inches of amendment grade pine bark tilled into the
upper six inches. On May 31, vegetative (to uppermost leaf) and
inflorescence heights of salvia and geranium were measured, and
shoots of the three species were cut for dry weight determination.
RESULTS
Growth of impatiens, geranium, salvia, marigold, and pansy
measured 4.5 to 8.5 weeks after treatment was significantly
suppressed by a single foliar spray of Sumagic (Tables 1-5). Plant
height, growth indices, and shoot dry weight of all species were
lower as concentration of Sumagic increased. Magnitude of sup-
pression varied with species and concentration. Growth indices of
impatiens, geranium, salvia, marigold, and pansy treated with five
ppm of Sumagic decreased 29.5, 10.2, 5.9, 2.5, and 1.4%, respec-
tively. Shoot dry weights of the same species decreased 52.3, 11.2,
22.2, 12.5, and 10.5%, respectively. Suppression of top dry
weight was most pronounced with application of the highest
concentration of Sumagic, 30 ppm, and equalled 81.0, 74.8, 44.4,
27.3, and 66.7% with impatiens, geranium, salvia, marigold, and
pansy, respectively. Foliar color ratings of impatiens increased
with higher concentrations of Sumagic. Foliar color of the other
species was not visibly affected by application of Sumagic.
Flowering varied with species used and with the concentra-
tion of Sumagic used. Flower number of impatiens, inflorescence
number of salvia, and peduncle number of pansy decreased with
an increase in the concentration of Sumagic. These reductions in
flowering appeared to be due to a delay in floral development
rather than an actual suppression of flowering because subsequent
observations on flowering in the landscape did not show treatment
differences. Flower buds of geranium were first observed on
March 29 on plants treated with the three highest concentrations
of Sumagic. This trend toward earlier floral development with the
highest concentrations of Sumagic continued through April and is
reflected in the inflorescence count taken on April 18. Flower bud
number of marigold averaged 10 to 12 per plant and was not
affected by treatment.
Sumagic had a significant effect on time to wilt of all species
except marigold. Time to wilt of impatiens increased from 39%
with three ppm of Sumagic to 63% with 30 ppm compared to the
control (Table 1). With geranium the increase was from 11% with
one ppm of Sumagic to 100% with application of 30 ppm of
Sumagic (Table 2). Wilting of salvia was delayed 15% with three
ppm of Sumagic and 34% with 30 ppm of Sumagic (Table 3). The
delay in wilting of pansy was negligible at concentrations of
Sumagic less than 20 ppm, but the time to wilt was increased by
35% with the application of 30 ppm of Sumagic.
As with the production and stress evaluation, plant response
to Sumagic five to seven weeks after transplanting into the
landscape varied with species and concentration. Plant height of
impatiens was suppressed less than 25% with application of one,
three, or five ppm of Sumagic compared to the control. Plants
treated with Sumagic at these concentrations were of excellent
quality. Shoot dry weight was inhibited by 26% with an applica-
tion of one ppm of Sumagic but increased to 74% with a 20 ppm
concentration.
Vegetative and inflorescence heights of geranium five weeks
after transplanting were not affected by application of 10 ppm or
less of Sumagic; concentrations greater than 10 ppm inhibited
plant height as much as 58%. Shoot dry weight of geranium
treatedwith 1, 3,5, and 10 ppmofSumagicwas7,12,25, and 15%,
respectively, greater than that of untreated plants. However, shoot
dry weight was suppressed 77% with 30 ppm Sumagic. Vegeta-
tive and inflorescence (flower cluster) heights and shoot dry
weights of salvia seven weeks after transplanting into the land-
scape were not affected by Sumagic concentration. Similarity of
heights indicates a more rapid rate of growth of Sumagic-treated
plants compared to untreatedplants. Accelerated growth of triazole-
treated plants has been observed after growth suppression effects
have dissipated and may relate to the accumulation of large
reserves of carbohydrates during the period of growth inhibition
that stimulate rapid growth as growth retardation lessens. The
high activity and persistence of triazole retardants are well docu-
mented and emphasize the importance of applying appropriate
concentrations.
Growth and flowering data taken on daminozide-treated
plants following production, during the stress evaluation or after
five to seven weeks in the landscape, did not differ from values for
untreated plants of the five bedding plant species. Therefore,
higher concentration and/or repeated application for effective
growth suppression are indicated. See Photos 9 and 10 on Page 19.
Keever is Professor of Horticulture and Foster is former Superinten-
dent of the Ornamental Horticulture Substation.
10
Table 1. Effects of Sumagic Foliar Sprays on Growth and Drought Stress Tolerance of New Guinea Impatiens
Treatment Growth index
1-
3 Foliar color
4  
Flower no. Time to wilt Height Shoot dry weight
5
8 WAT
6  
15WAT
ppm cm hr. 
cm g g
Sumagic
0 ............................................ 23.7 4.0 4.9 20.5 20.6 4.2 28.2
1 ....................... ........................ 21.6 4.3 3.0 19.4 19.2 3.1 20.9
3 ............................................ 15.6 4.8 2.0 28.5 16.0 1.8 14.5
5 ............................................ 16.7 5.0 3.4 30.5 16.2 2.0 15.9
10 ....................... ...................... 14.8 5.0 2.3 32.2 14.0 1.9 8.0
15 .......................................... 14.9 5.0 2.6 32.8 15.6 1.2 10.2
20 ............................................................ 14.2 5.0 0.4 33.5 13.3 0.9 7.4
30 ..................... ....................................... 13.8 5.0 0.0 33.5 11.4 0.7 11.5
Daminozide
5,000 ................................. .......... 21.2 4.1 3.8 17.2 20.2 3.1 23.4
Table 2. Effects of Sumagic Foliar Sprays on Growth and Drought Stress Tolerance of Geranium
Treatment Growth index
1,3 ,7 
Inflorescences
7,12 
Time to wilt Vegetative ht.
8  
Flowering ht.' Shoot dry weight
5
10 WAT
6  
15 WAT
ppm cm no. hr. cm cm 
g g
Sumagic
0 ............................................. 26.6 1.6 9.7 18.0 28.8 14.3 39.2
1 ............................................................. 25.5 1.1 10.8 17.4 28.6 14.0 42.0
3 ............................................ 25.5 1.3 10.5 17.8 28.0 15.0 43.8
5 ........................... ................. 23.9 1.4 11.4 18.8 29.2 12.7 49.0
10 ....................... ....................... 22.9 1.5 10.9 17.4 27.0 12.6 45.1
15 .......................................... 19.0 1.6 12.5 11.0 19.4 7.8 30.8
20 ............................................ 17.1 1.9 14.8 11.4 18.8 5.2 19.8
30 .......................................... 14.7 2.1 19.4 7.6 12.8 3.6 8.9
Daminozide
5,000 ........................... ... .......... 24.8 1.1 11.4 17.6 28.4 11.2 41.5
Table 3. Effects of Sumagic Foliar Sprays on Growth Table 4. Effects of Sumagic Foliar Sprays on Growth
and Drought Stress Tolerance of Salvia and Drought Stress Tolerance of Marigold
Treatment Growth Inflorescence Shoot Time Treatment Growth Shoot
index
1-
3 no.
2  
dry weight
5 ,9  
to wilt index
,3,10  
dry wt.
ppm cm g hr. ppm cm 
g
Sumagic 
Sumagic
0 .................................. 30.7 1.9 6.3 14.2 0 ....... .......... ..... .......................... 20.1 8.8
1 .................................. 28.8 2.1 4.9 13.7 1 ....... .......... ..... ......................... 19.9 8.9
3 .................................. 29.0 1.3 4.1 16.3 3 ............................................................... 19.7 8.7
5 .................................. 28.9 1.1 4.9 15.8 5 ............................................................... 19.6 7.7
10 ................................. 29.0 0.5 4.7 16.6 10 .............................................................. 17.7 8.0
15 ................................. 26.1 0.2 4.6 18.0 15 .............................................................. 17.6 7.5
20 ................................. 26.2 0.3 3.7 18.1 20 ....... .......... ..... ......................... 17.4 7.7
30 ................................. 23.2 0.1 3.5 19.0 30 ....... .......... ..... ......................... 16.7 6.4
Daminozide Daminozide
5,000 ............................ 28.6 1.1 4.4 16.1 5,000 ........................................................... 19.4 7.0
Table 5. Effects of Sumagic Foliar Sprays on Growth FOOTNOTES: TABLES 1-5
and Drought Stress Tolerance of Pansy 
Growth index (height ? width + width
2
)/3. Width was at the
Treatment Growth Peduncles
1
,
3  
Time Shoot
5 7  
One centimeter (cm) is .3937 inch.
index
1,3,
11 to wilt dry wt. 
4
Foliar color rating: 1, 3, and 5 = light, medium, and dark green, respec
0 ............................... 20.9 3.7 
17.4 5.7 'WAT = weeks after 
treatment on February 16; 1989. Plants wer
1 ............................... 22.3 3.6 
16.5 5.5 transplanted into the landscape 
eight weeks after treatment.
3 ............................... 21.7 4.0 16.0 5.4 
7
Measurement taken 8.5 weeks after treatment.
5 .................................. 20.6 4.2 17.5 5.1 'Measurement taken 15 weeks after treatment.
10 ............................. 18.8 3.7 17.9 4.5 'Measurement taken eight weeks after treatment.
15 ................................. 16.9 2.7 17.3 3.4 "0Measurement taken 4.5 weeks after treatment.
20 ................................. 14.1 2.7 19.8 2.7 "Measurementltaken 
six weeks after treatment.
30 ................................. 11.0 2.2 23.5 1.9 1nflorescence (flower cluster).
Daminozide 
e n or s lk ser
5,000 ........................... 20.9 3.9 16.6 4.8 Peduncle (stalk).
11
Growth and Flowering of Triazole-Treated Zinnia and Marigold
Chia-Lun Chen, Gary J. Keever, and C. Fred Deneke
Triazole-based plant growth inhibitors paclobutrazol and
uniconazole are effective on bedding plants at relatively low
dosages and persist for a long time. This persistence has some
advantages, but it could also result in undesirable growth inhibi-
tion during production, marketing or after planting in the land-
scape.
BAS111 is a triazole derivative previously evaluated as a
growth regulator for fruit trees. It appears to have similar regulat-
ing activity as paclobutrazol and uniconazole, but it is less
persistent, a factor that could be a distinct advantage to bedding
plants growers. In an AAES study, paclobutrazol, uniconazole,
and BAS 111 were evaluated to determine effects on growth and
flowering of zinnia and marigold during greenhouse production.
Results showed a single foliar spray of 250-750 ppm of
paclobutrazol or uniconazole provided acceptable height control
from two weeks after treatment to flowering. Plants flowered
earlier, but flower clusters of uniconazole-sprayed plants were
smaller. BAS111 temporarily suppressed vegetative growth of
zinnia, but at flowering plants were similar in size to untreated
plants. Marigold growth and flowering height were not controlled
by either paclobutrazol or BAS111, but uniconazole provided
acceptable control of plant height. Lack of growth control may be
due to paclobutrazol concentration being too low, although other
research achieved acceptable control with a similar concentration
using a different cultivar.
METHODS
Seeds of Sunrise Yellow zinnia and Inca Yellow marigold
were direct-sown in 0.95-quart standard pots and 0.8-quart azalea
pots, respectively, on Feb. 1, 1990. The growing medium for the
two species was 7:1 pine bark:sand (by volume) amended with six
pounds dolomitic limestone, 1.5 pounds Micromax micronutrient
fertilizer, and 12 pounds Osmocote 14-14-14 per cubic yard.
Seedlings were fertilized weekly with 300 ppm nitrogen from a
water soluble 20-10-20 fertilizer. Plants were grown in a polyeth-
ylene-covered greenhouse with a ventilation setpoint of 80oF and
a heat setpoint of 65
0
F. Growth retardants were applied at the
second-pair true-leaf stage on Feb. 28, 1990, 27 days after sowing.
Treatments included a single foliar spray of paclobutrazol,
uniconazole, or BAS111 of 250-750 ppm to zinnias and 20-60
ppm to marigolds. An untreated control was included with each
plant species.
Plant height from the growth medium surface to the growing
point was measured when treatments were applied and each week
thereafter until flowering. When the first inflorescence (flower
cluster) of each plant was fully opened, the height from the surface
of the growth medium to the top of the first inflorescence, growth
index (see table footnotes for definition), the diameter and the
peduncle (stalk) length of the first opened inflorescence, the
number of inflorescence buds (bud diameter greater than 0.4
inch), and days to flower were determined.
RESULTS
By the second week after treatment with paclobutrazol and
uniconazole, or the third week after treatment with BAS 111, and
continuing through flowering, plant height of zinnia was reduced
with increasing rates of the compounds (Table 1). Growth sup-
pression, as indicated by plant height, at two weeks after treatment
ranged from 7% with the lowest concentration of paclobutrazol
and uniconazole to 16 and 20%, respectively with the highest
concentration. By week three, growth suppression from the low-
est and highest concentrations relative to the control was 27 and
44% with paclobutrazol, 41 and 58% with uniconazole, and 4 and
24% with BAS111.
Growth indices, determined when the first inflorescence of
each plant was fully opened, were least when plants were sprayed
with uniconazole, ranging from 11-19% less than those of control
plants. Growth indices of paclobutrazol-treated plants were 2-
Table 1. Influence of Foliar Application of Paclobutrazol, Uniconazole, and BAS111I on Growth and Flowering of Sunrise Yellow 
Zinnia
Treatment Plant height' Growth Inflorescence 
Days Inflorescence
Week 1 Week 2 Week 3 index
2-4  
height' to flower
3  
diameter
3
ppm cm cm cm cm cm cm
Control
0 ................................. ........................ 6.4 12.6 21.5 31.1 30.7 37.6 
6.6
Paclobutrazol
250 .............................. ............................ 5.9 9.7 15.8 30.4 
26.8 36.9 6.1
500 ............................ .................................... 5.1 7.5 12.4 26.7 
21.7 26.3 6.2
750 ......................................... ....................... 5.4 7.9 12.1 27.4 
22.2 26.9 6.1
Uniconazole
250 .............................................................. 5.9 8.4 12.7 27.8 21.2 28.4 
6.2
500 ............................................................. 5.0 7.0 10.2 27.8 
20.6 27.1 5.6
750 ............................................................. 5.1 6.9 9.1 25.2 
18.2 20.1 5.4
BAS111
250 ............................................................... 5.9 11.8 20.7 30.4 
31.3 39.7 6.7
500 ............................................................... 5.7 9.8 16.8 31.4 
31.5 37.7 6.1
750 ......................... .. ...................... 6.0 10.3 16.4 30.4 
28.9 36.9 6.5
'Plant heights were measured weekly beginning one week after treatment; height was measured from 
the medium surface to the uppermost vegetative part of the plant.
2
Growth index = (height + width
1 
+ width
2
)/3. Width
1 
was at the widest point and width
2 
was perpendicular to width,.
3
Data were determined when the first inflorescence was fully opened; height was measured from the medium surface to the top of the inflorescence.
4
One centimeter (cm) is .3937 
inch.
12% less than those of control plants, while growth indices of
BAS 111-treated plants were similar to those of control plants.
Inflorescence heights were similarly affected by treatments.
Heights were less with increased concentrations of paclobutrazol
or uniconazole and not affected by BAS 111 concentration. Mag-
nitude of suppression was of the following order: uniconazole >
paclobutrazol > BAS111. The reduced persistence of growth
retardation should ensure that plants resume a normal rate of
growth after being planted in the landscape.
Time to flower decreased with increasing concentrations of
paclobutrazol and uniconazole to a maximum of 28% and 47%,
respectively, with the highest concentration of each growth regu-
lator. BAS111 did not influence time to flower. Inflorescence
diameters were affected only by uniconazole, decreasing as con-
centration was increased. Peduncle lengths or inflorescence num-
bers were not affected by either treatment or concentration.
Leaves of plants sprayed with the compounds and control plants
visually appeared similar in color, size, and shape.
Weekly heights of marigold prior to flowering and time to
flower were not influenced by treatment or concentration. Growth
indices and inflorescence heights and numbers decreased with
increasing concentrations of uniconazole, but not with
paclobutrazol or BAS 111 (Table 2). Decreases in growth indices,
inflorescence heights, and inflorescence numbers ranged from 6-
9%, 6-19%, and 16-21%, respectively. Peduncle lengths were not
affected by concentration, although peduncles of plants sprayed
with uniconazole were shorter than those of plants sprayed with
other regulators or control plants. Inflorescence diameter de-
creased with increasing concentrations. Inflorescences were simi-
lar in diameter for all treatments.
Chen is former Graduate Student, Keever is Professor, and Deneke is
former Assistant Professor of Horticulture.
Table 2. Influence of Foliar Application of Paclobutrazol, Uniconazole, and BAS111 on Growth and Flowering of Inca Yellow Marigolds
Treatment Growth index
2-4  
Inflorescence height' Peduncle length Inflorescence no.
3  
Inflorescence diameter
Control
0 ......................................... 24.2 19.9 6.4 13.2 9.1
Paclobutrazol
20 ....................................................................... 23.8 19.6 6.6 13.3 8.7
40 ......................................... .......................... 24.2 19.1 6.7 12.7 8.4
60 ......................................... .......................... 23.4 19.0 6.4 12.1 8.3
Uniconazole
20 ..................... . ....................... 22.7 17.8 6.0 11.1 8.6
40 ...................... . ....................... 22.3 17.2 6.1 10.2 8.5
60 .................... ........................ 22.0 16.2 5.7 10.4 8.4
BAS111
20 ......................................... .......................... 24.3 18.0 5.9 12.1 8.3
40 ......................................... .......................... 24.6 19.2 6.7 12.2 8.3
60 ......................................... .......................... 23.1 19.1 6.6 12.3 8.4
1
Plant heights were measured weekly beginning one week after treatment; height was measured from the medium surface to the uppermost vegetative part of the plant.
2
Growth index = (height + width
1 
+ width
2
)/3. Width was at the widest point and width
2 
was perpendicular to width
1
.
3
Data were determined when the first inflorescence was fully opened; height was measured from the medium surface to the top of the inflorescence.
4
One centimeter (cm) 
is .3937 inch.
Chemical Promotion of Axillary Shoot Development of Geranium Stock Plants
James T. Foley and Gary J. Keever
The maintenance of geranium stock plants as a source of
vegetatively propagated cultivars requires a continual investment
in space and labor. Greater efficiency is possible if the number of
cuttings per plant is increased, thus reducing the total number of
stock plants maintained. Chemical growth regulators can be used to
double or triple branching in geraniums, thereby increasing the
number of terminal or single-node cuttings per stock plant.
Florel (ethephon), which is labeled as a branching compound
for use on geranium stock plants at a concentration of 500 parts per
million (ppm), is well-documented for its promotion of axillary
shoot development. Other plant growth regulators, such a's the
synthetic cytokinins Pro-Shear (BA) and Accel (PBA), reduce
apical dominance, promoting the growth of axillary buds. Three
experiments were conducted to determine the effectiveness of
these three chemicals, plus Promalin (BA + GA
4+7
), at inducing
axillary shoot development of Hollywood Star geranium stock
plants for the purpose of increasing the production of cuttings.
In this study, calipers of terminal cuttings were less in
Florel-treated plants than in untreated plants. Two applications
of Promalin at 75 or 150 ppm increased production of single-
node cuttings, without reducing the number or caliper of the
terminal cuttings. The use of Promalin is a viable alternative to
the industry standard, Florel, for increasing the total number of
marketable geranium plants produced from single-node cuttings.
METHODS
Experiment 1. On Nov. 13, 1987, seeds of Hollywood Star
geranium were sown in 36-cell flats of Pro-Mix BX. Seedlings
were transplanted to six-inch pots of identical growth medium on
Jan. 6, 1988. After two days, the following foliar spray treat-
ments were applied to the plants just prior to runoff: Pro-Shear
at 75-600 ppm; Accel at 75-600 ppm; or Promalin at 150-1,200
ppm. An untreated control was included for comparison. Buffer-
X was added as a surfactant at 0.2% to all chemical solutions in
each experiment. Plants were fertilized weekly with 200 ppm
13
nitrogen from 20-10-20 Peter's Peatlite Special. At the termina-
tion of the experiment, eight weeks after plant treatment, data
collected included the number of axillary shoots, the mean length
of three randomly selected axillary shoots, and a growth index
(see table footnotes for definition).
Experiment 2. A second study was initiated to determine
appropriate concentrations and numbers of applications of the
branching compounds Accel, Promalin, and Florel on geranium
stock plants. Seeds were sown on April 4, 1988, and the seedlings
were grown as in the first experiment. The following foliar spray
treatments were applied on June 27, 1988: Accel at 37.5 or 75
ppm.; Promalin at 75 or 150 ppm; or Florel at 500 ppm. A control
treatment was included for comparison. Four weeks after initial
treatment, terminal and single-node cuttings were taken, and a
second application was applied to half of the plants in each
treatment group. Plants were then allowed to produce a second
crop of cuttings. All side branches were cut from the main leader
of each plant and divided into terminal cuttings (about four inches
long) and single-node cuttings (with leaf attached). Data collected
at the first and second removal of cuttings consisted of lengths and
calipers of axillary shoots and numbers of terminal and single-
node cuttings. The caliper of each side shoot was taken at the point
of detachment from the main leader and the lengths of side
branches were also measured from this point to the vegetative
shoot apex.
Experiment 3. A third experiment compared the effects of
one, two, or four foliar sprays of Promalin at 75-300 ppm or Florel
at 500 ppm. An untreated control was included for comparison.
Seeds were sown on March 2, 1989, and seedlings were grown as
in the first two experiments. The first foliar spray application was
on May 4, 1989; additional applications were made at two-week
intervals. At time of cutting, the number of terminal and single-
node cuttings and lengths and calipers of axillary shoots were
recorded.
RESULTS
Experiment 1. As the concentration of Pro-Shear increased,
the numbers of axillary shoots decreased (Table 1). When Pro-
Shear was applied at 600 ppm, axillary shoot formation was
suppressed; there was no effect at lower concentrations. Axillary
shoot length increased as concentration of Pro-Shear increased,
but the growth index was not affected by application of Pro-Shear.
Pro-Shear was not studied further since axillary shoot number was
not increased following its application.
Axillary shoot number was increased at lower concentrations
of Accel, with no effect thereafter. Axillary shoot length was not
affected by Accel application. The growth index increased with
Accel up to 300 ppm but declined at higher concentrations.
Axillary shoot number did not differ from the control at the
two highest concentrations of Promalin, while numbers increased
at the 300 ppm concentration. Although axillary shoot lengths
increased linearly as concentration of Promalin increased, lengths
did not differ from the control. The growth index increased with
increasing concentration of Promalin, with 1,200 ppm producing
a growth index greater than the control.
Experiment 2. The first cuttings were harvested four weeks
after initial treatment. More terminal cuttings were produced
following Florel application than with the other treatments (Table
2). Treatment with Accel at 75 ppm or Promalin at 75 or 150 ppm
increased the numbers of terminal cuttings, but the increase was
not as great as with Florel. The number of single-node cuttings
was not affected by applications of Florel, Accel, or Promalin
after the first cuttings had been harvested. Axillary shoot length
and caliper of plants treated with Florel were less than all other
treated and control plants. When Promalin was applied at 150
ppm, axillary shoot length was increased. Applications of Accel
did not affect axillary shoot length. Axillary shoot caliper was not
affected by treatment with Promalin or Accel.
After harvesting a second crop of cuttings, number of termi-
nal cuttings did not differ among treatments. The numbers of
single-node cuttings increased after a second application of 75 or
150 ppm Promalin. The number of single-node cuttings did not
differ from that of control plants with a second application of
Accel or Florel. The lengths of axillary shoots were increased with
a second application of Promalin at 150 ppm; axillary shoot
lengths of plants in other treatments were similar to those of
control plants. Calipers of cuttings from plants treated with Florel
or one application of Promalin at 75 ppm were reduced. Calipers
of plants given other treatments did not differ from those of
control plants.
Experiment 3. Application of Florel increased the number
of terminal cuttings (Table 3). Foliage of plants receiving four
applications of Promalin at 150 or 300 ppm was chlorotic, and
isolated marginal leaf necrosis was present. Phytotoxicity possi-
bly contributed to reduced numbers of terminal cuttings. Numbers
of terminal cuttings were also decreased by a single application of
Promalin at 300 ppm, indicating an excessive concentration was
applied. The numbers of terminal cuttings from plants receiving
other concentrations of Promalin were similar to those of control
plants. The number of single-node cuttings was increased by two
applications of Promalin at 75 ppm, while numbers decreased
from four applications at 300 ppm. The other application numbers
and concentrations of Promalin and Florel had no affect on single-
node cutting number.
Table 1. Number and Length of Axillary Shoots and Growth Index
of Geranium as Affected by Three Plant Growth Regulators,
Eight Weeks After Treatment (Experiment 1)
Treatment No. shoots Shoot Growth
length' index
2
ppm cm cm
BA
75 ....................... . .......................... 16.2 9.5 25.1
600 ............................. 6.5 13.3 25.6
Accel
75 ............................. 17.6 10.3 25.8
150 . . ................. 16.6 11.5 26.5
300 ........ 17.0 11.1 28.1
600 ............................. 13.6 10.2 25.7
150 ........................ .......................... 10.2 8.7 25.8
300 ......................... .. ........................ 17.2 10.8 25.5
600 ............................................... 14.0 10.2 26.5
1,200..............................11.4 12.2 28.4
Control
0 .......................................................... 13.6 9.4 24.2
See footnotes on following page.
Table 2. Terminal and Single Node Cutting Numbers and Length and
Caliper of Axillary Shoots of Geranium from First and Second Harvests
as Affected by Three Plant Growth Regulators (Experiment 2)
Treatment
3  
Terminal Single-node Shoot Shoot
cuttings cuttings length
1  
caliper
no. no. cm cm
First harvest
4
Accel
375(1). ........................... 9.5 11.3 9.8 0.80
75(1) ....................... 10.0 10.5 9.6 0.79
Promalin
75(1) .............................. 9.9 9.6 11.3 0.79
150(1) ........................ 10.4 13.6 12.5 0.88
Florel
500(1) ............... 16.2 10.8 7.3 0.68
Control
0(0) .............................. 8.4 12.3 10.2 0.82
Second harvest4
Accel
37.5(1)............................9.4 13.4 9.5 0.79
37.5(2)............................ 8.7 19.3 12.8 0.82
75(1) ............................... 9.4 18.1 10.7 0.81
75(2) ............................... 7.3 16.8 11.2 0.78
Promalin
75(1) ............................... 9.9 8.9 8.1 0.74
75(2) ............................. 10.9 25.7 12.7 0.79
150(1) ............................. 8.7 17.4 11.5 0.80
150(2) ............................. 9.0 27.9 13.5 0.82
Florel
500(1)...........................11.0 16.6 9.0 0.68
500(2) ........................... 10.2 17.2 9.5 0.69
Control
0(0) ................................. 9.0 16.1 10.1 0.88
The lengths of axillary shoots were reduced by application of
Florel. One application of Promalin at 150 or 300 ppm or two or
four applications at 75 or 150 ppm increased axillary shoot length.
Axillary shoot caliper decreased when plants were treated with
four applications of Promalin, two applications of 300 ppm
Promalin, or with Florel.
Florel produced more terminal cuttings than the other plant
growth regulators, but plants had shorter axillary shoots of smaller
calipers when compared to the control and Promalin treated
plants. Plants treated with Promalin produced longer axillary
shoots of increased caliper, resulting in an increased number of
single-node cuttings when compared to plants treated with Florel.
In addition to an unaltered number of terminal cuttings, the
increased number of single-node cuttings produced from stock
plants treated with two applications of Promalin at 75 ppm
biweekly, doubled or tripled the total number of cuttings pro-
duced. This effect would potentially result in a substantial in-
crease in the total number of marketable cuttings produced.
Foley is former Graduate Student and Keever is Professor of Horticul-
ture.
Table 3. Terminal and Single Node Cutting Numbers and Length and
Caliper of Axillary Shoots of Geranium as Affected by Two Plant
Growth Regulators, Seven Weeks after Treatment (Experiment 3)
Treatment
3  
Terminal Single-node Shoot Shoot
cuttings cuttings length
1  
caliper
no. no. cm cm
Promalin
75(4) ......................... . 11.4 24.4 17.6 0.72
75(2) .......................... 12.5 27.4 15.6 0.83
75(1) ............................. 12.5 20.5 12.2 0.79
Promalin
150(4) ........................ 10.3 15.7 14.6 0.62
150(2) ........................ 11.8 23.1 15.5 0.79
150(1) ........................ 13.7 23.6 14.4 0.80
Promalin
300(4) ......................... 9.6 6.2 10.0 0.60
300(2) ........................... 11.0 16.9 13.1 0.70
300(1) ........................... 10.8 19.5 14.3 0.90
Florel
500(1) ........................... 14.3 14.3 5.7 0.68
Control
0(0) ............................... 12.6 16.5 10.7 0.87
'One centimeter is .3934 inch.
2
Growth index = (height + width + width
2
)/3. Width
1 
was at the widest point, and
width
2 
was perpendicular to width .
3
The first number is the application rate in parts per million, while the number
in parentheses is the application number: 1 = monthly; 2 = biweekly; 4 = weekly.
4
First cut made four weeks after initial treatment; second 
cut taken nine weeks
after second application of treatment.
7C(d\ 11 a 34 a 17 f; n 73
WOODY ORNAMENTALS
Comparison of Two Root Control Techniques for the Urban Landscape
Patricia R. Knight, D. Joseph Eakes, and Charles H. Gilliam
Tree root encroachment poses several problems to the land-
scape industry. Trees planted too close to walks, parking lots, or
streets can cause concrete or asphalt to buckle. Root encroach-
ment may also cause aesthetic problems by surfacing in ornamen-
tal landscape beds. Current methods of controlling root encroach-
ment, usually involving mechanical removal of the roots, are
expensive and tend to provide short-term solutions.
Physical and/or chemical barriers that prevent growth of
unwanted roots are being investigated as a more economical and
permanent alternative. Based on previous work, Typar Biobarrier
(Reemay, Inc., Old Hickory, Tenn.) and DeWitt Pro-5 Weed
Barrier (DeWitt Co., Inc., Sikeston, Mo.) were chosen as potential
root barriers for an AAES study. Objectives were to evaluate these
products in the urban landscape and to determine their influence
on the growth of two tree species commonly grown as street trees.
Typar Biobarrier is a time-released material first developed
to control root encroachment into hazardous waste burial sites. It
is comprised of 0.35-inch spheres that are 24% trifluralin, 18%
carbon black, and 56% polyethylene. The herbicide-impregnated
nodules are bonded to a permeable geotextile fabric. DeWitt Pro-
5 Weed Barrier is a woven polyethylene fabric that provides
excellent weed control in the landscape.
Typar Biobarrier effectively controlled root growth for red
maple and American sycamore without producing negative ef-
fects on tree growth and development during the first two years of
this study. In comparison, DeWitt Pro-5 failed to prevent root
growth outside the treatment's vertical plane for either species.
METHOD
Two-inch caliper Acer rubrum (red maple) and Platanus
occidentalis (American sycamore) were planted at the E.V. Smith
Research Center on March 26, 1990. The planting holes were 8x8
feet and 19 inches deep. Sides of each hole were lined to a depth
of 18 inches with either Typar Biobarrier, DeWitt Pro-5, or left
unlined as a control. One inch of the fabric was left above the soil
surface to prevent roots from growing over the vertical barriers.
Trees were placed in the center of the hole, and holes were
backfilled. After planting, trees were mulched to a depth of two to
three inches with pine bark, watered as needed during the first
year, and fertilized annually with one pound of 13-13-13 per inch
of caliper. Roundup was used for postemergence weed control
around the edge of the planting hole.
Root penetration, height, and caliper were determined fol-
lowing the 1990 and 1991 growing seasons. To determine root
penetration through the vertical plane of each treatment, one side
of the planting hole (eight feet long) was excavated with abackhoe
to within four inches of the vertical plane. The remaining four
inches of soil was removed by hand, and all roots penetrating the
vertical plane were counted.
RESULTS
There was little or no root penetration by either species
beyond the Typar Biobarrier root control treatment following the
1990 or 1991 growing season (see table). At the end of 1990, the
untreated control and DeWitt Pro-5 treatments had similar root
penetration numbers for both species. In contrast, by the end of
1991 the DeWitt Pro-5 treatment had more roots penetrate the
vertical barrier than the control treatment for red maple. Roots that
penetrated the DeWitt Pro-5 treatment tended to branch as they
penetrated the barrier resulting in small roots that grew along the
face of the vertical barrier.
There were no treatment differences in height or caliper for
red maple or American sycamore either year. Average height and
caliper for red maple across the three treatments were 13.3 feet and
2.2 inches in 1990 and 17.2 feet and 3.5 inches in 1991, respec-
tively. For American sycamore, average height and caliper across
the three treatments were 15.6 feet and 2.5 inches in 1990 and 17.8
feet and 3.8 inches in 1991, respectively.
In May 1991, soil samples were taken horizontally from the
area surrounding a Typar Biobarrier treatment to evaluate triflu-
ralin movement in the soil. Trifluralin levels were highest, 24.1
parts per million (ppm) up to 1/8 inch from the Typar Biobarrier,
and concentration decreased as distance from the Typar Biobarrier
increased. At a distance of two inches from the Typar Biobarrier,
the trifluralin concentration had decreased to 0.1 ppm. The nodule
trifluralin concentration was comparable to the original herbicide
content of the nodule.
Root Penetration Through Vertical Plane of Root Control Treatments
Treatment Num
Red Maple
1990 1991
Typar Biobarrier ............... 0.0 0.0
DeWitt Pro-5 .................. 11.7 58.7
Untreated Control...........17.0 28.3
ber of roots
American Sycamore
1990 1991
0.0 1.0
16.3 58.0
22.0 53.7
Knight is Graduate Research Assistant, Eakes is Assistant Professor, and
Gilliam is Professor of Horticulture.
Ivn~r Ki~n~rilpr P.ttPr.T1VPIV r.nntmllp.rl rnnt Drnwti7 tnr rP.n fppt ann ~ X inrhp
16
Influence of Subirrigation and Container Size on Growth of Two Tree 
Species
Ken M. Tilt, Ronald L. Shumack, and John W. Olive
Overhead irrigation of a container nursery requires about
20,000 to 40,000 gallons of water per acre each day. Some 70-80%
of this water falls between or passes through the containers and
runs off the nursery. There is strong concern for preventing
ground water contamination that could be caused by runoff of
pesticides and fertilizers in the wasted irrigation water.
Some nurseries have already implemented conservation mea-
sures to address these concerns. One method has been to channel
runoff to holding ponds where it is filtered and recycled. Another
production technique is to use drip irrigation where each container
has its own water source. This method prevents tremendous loss
of water but is only economically feasible in larger containers and
can still result in runoff.
AAES research evaluated the effects on growth of live oak
(Quercus virginiana) and Shumard oak (Quercus shumardii) as a
result of catching the leachate or water passing through the
container and holding it in reserve in a saucer. A second objective
was to determine whether a constant water level maintained in the
saucer beneath the containers would be detrimental to or enhance
growth compared to allowing the saucer to dry out between
irrigations.
This study proved that equal or better growth of the trees can
be obtained using subirrigation while eliminating any water
runoff. Proper selection of container size for the plant being grown
can increase growth and profits. These results represent positive
Table 1. Effect of Subirrigation on Growth of Two Tree Species
Irrigation Live Oak Shumard Oak
Height Caliper Height Caliper
ft. in. ft. 
in.
Control .............................. 5.1 1.4 5.5 1.0
Dry ...............
.. . . . . . . . . . . . . . .
.... 7.2 1.9 6.1 1.0
W et
2 
...............
. . . . . . . . . . . . .
.
. . .
6.7 1.9 5.4 1.0
1
1.5-inch saucer was filled with water after it dried out.
2
1.5-inch saucer was maintained filled with water at all times.
implications for further research to increase or maintain produc-
tion efficiency while increasing the commitment toward conser-
vation and preservation of natural resources.
METHODS
Trees were planted Jan. 18, 1988, and were analyzed sepa-
rately. Fifteen- and 30-gallon containers were used to determine
the size of containers needed to facilitate optimum growth. Some
trees were given a "subirrigation-wet" treatment, in which a 1.5-
inch saucer was placed under the container and maintained 
filled
with water at all times. Other trees received a "subirrigation-dry"
treatment, in which the saucer was filled with water as it dried out.
A control group of both species was given traditional drip irriga-
tion. All plants received the same cultural care throughout 
the
experiment, except for the irrigation treatments. The height 
and
caliper of each tree was measured on Oct. 10, 1989.
RESULTS
Live oaks had greater caliper and height for either subirrigation
treatment compared to the control drip irrigation treatment (Table
1). There were no differences in growth for Shumard oak due to
the irrigation treatments.
There was a clear growth benefit to growing the trees in 30-
gallon containers over 15-gallon containers for the two-year
study. Live oak and Shumard oak grown in 30-gallon containers
were 0.8 foot and 1.6 feet taller than 15-gallon container trees,
respectively (Table 2).
Table 2. Effect of Container Size on Growth of Two Tree Species
Irrigation Live Oak Shumard Oak
Height Caliper Height Caliper
ft. in. ft. 
in.
15 gal................................. 5.8 1.5 5.0 1.1
30 gal ................................. 6.6 1.9 6.6 1.0
Tilt is Associate Professor and Shumack is Department Head and
Professor of Horticulture; Olive is Superintendent of the Ornamental
Horticulture Substation.
Effects of Water Reservoirs on Growth of Container-Grown 
Pecan and Pear Trees
Ken M. Tilt, William D. Goff, Ronald L. Shumack, and John W. Olive
Despite research on efficiency of water use for container-
grown plants, nursery practices for scheduling irrigation to con-
tainer-grown woody ornamentals is often imprecise and subjec-
tive. The nursery industry is under pressure and is cooperating to
make sure its management practices do not adversely affect the
environment.
Commonly, nursery producers will examine the moisture in
the top inch of medium; if it is dry, they apply sufficient irrigation
to thoroughly rewet the medium. This system can result in fluctu-
ating levels of excessive and deficient moisture. Excessive mois-
ture results in inadequate root aeration and can contribute to
increased incidence of root-rot diseases. Deficient moisture can
also stress plants and result in disease and loss of growth. Im-
proved water management is necessary not only for plant growth
but also to reduce the impact of excessive water runoff.
One possible way to improve water management for con-
tainer trees is to adapt the principles of subirrigation to container
production. In subirrigation, a water table is maintained at a
certain depth beneath the soil surface. Capillary action ensures
sufficient water is readily available to plant roots. Roots also move
down to the water table. An AAES study examined the effect of
growing pecan (Carya illinoensis Melrose) and pear (Pyrus
calleryana Bradford) trees in containers with a water-holding
reservoir at the container base.
Results of the study show equal or better tree growth can be
realized through subirrigation or water reservoirs. Data suggest
that improved growth is related to continuous root access to water.
If these methods are economically feasible to implement, then an
opportunity exists for improving profits while acting as respon-
sible role models in preserving natural resources.
METHODS
Thirty-six, three-gallon Melrose pecan trees and 36 field-
grown Bradford pear trees were selected for uniformity in March
1991 to be used in the experiment. The trees were subjected to two
treatments plus a control: raised holes, subirrigation, and tradi-
tional containers. The raised hole (EFC) treatment had trees
grown in 20-gallon containers, but with the drainage holes located
2.5 inches from the container bottom (distance measured from
bottom of container to bottom of the drainage holes). The drainage
holes were the same in size as in the standard containers and
distributed evenly around the container. Spot-spitter irrigation
was used as described for the control treatment. This system was
developed and patented by Robert Rigsby of Rigsby Nursery, Ft.
Myers, Fla. The containers are sold under the name Environmen-
tally Friendly ContainersTM (EFC).
The subirrigation treatment was provided by constructing
water-holding frames from wood lined with plastic, and placing
the containers in the frames. No surface irrigation was provided
for these containers, except for rainfall. The frame dimensions
were 3x3 feet and 2.5 inches deep. Control treatment trees were
grown in 20-gallon traditional polyethylene containers with four
one-inch drainage holes at the bottom of the container. Irrigation
was provided by two spot-spitter emitters. The emitters used a
semi-circular spray pattern sufficient to wet the entire surface of
the medium. Plants were irrigated when the upper one inch of
medium was dry.
The frames were filled with water to the full depth, and were
refilled whenever the level of water in the frame dropped to half-
full. Water entered the container through the drainage holes in the
bottom, and saturated the medium in the lower part of the con-
tainer.
Trees were transplanted in March 1991 into the three contain-
ers containing milled pine bark:sand (6:1) medium amended with
11 pounds Osmocote 18-6-12, 1.5 pounds Micromax micronutri-
ents, and six pounds dolomitic limestone per cubic yard. Supple-
mental Osmocote 18-6-12 was topdressed at the same rate in April
1992.
Plant height and trunk caliper were measured at transplant-
ing, and on Aug. 23, 1991, and Nov. 18, 1992. Of the 12 trees in
each treatment, four were randomly selected for shoot fresh
weight determination.
RESULTS
Shoot growth measurements of pear trees were significantly
greater when trees were grown in EFC (raised hole) containers,
although plant height was not affected by container treatment.
Subirrigation and control treatments were similar for all variables
measured with both tree species. With pecan trees, the EFC
containers had greater caliper and shoot fresh weight than the
control treatments (see table).
When plants were removed from the containers and root
systems were examined, it was obvious that roots were absent in
the poorly-aerated layer where water stood at the bottom of the
containers with water reservoirs. The absence of roots in the lower
layer of medium in the treatments with water reservoirs contrasted
sharply with the proliferation of roots at the bottom of containers
in the treatments with free drainage. No pathological study of root
microorganisms was done. If pathogenic fungi such as
Phytophthora were present in the containers with water reservoirs,
their influence was not detrimental to top growth or was overrid-
den by other favorable conditions. There were no difference in dry
weight of roots among the three container treatments. Plants in
containers with reservoirs compensated for loss of root growth in
the bottom of the containers by increasing root mass in the tops of
the containers. See Photos 11-13 on Page 19.
Effect of Irrigation Treatments on Growth of Pecan and Pear Trees'
Treatment Caliper Caliper Height Shoot
increase weight
in. pct. ft. lb.
Pear
Raised holes...................1.8 305 8.2 9.5
Subirrigation .................. 1.5 246 7.9 6.2
Control ........................... 1.4 219 7.9 5.5
Pecan
Raised holes...................1.7 138 7.9 4.2
Subirrigation..................1.5 116 8.2 3.5
Control ........................... 1.3 91 7.2 2.4
'Percent increase is from treatment initiation at repotting in March 1991 until
Nov. 18, 1992, when growth measurements were made. Measurements were
made after two seasons of growth.
Tilt and Goff are Associate Professors and Shumack is Department
Head and Professor of Horticulture; Olive is Superintendent of the Orna-
mental Horticulture Substation.
Growth of Container-Grown Trees Transplanted from the Field or Grow-Bags
Kenneth M. Tilt, Charles H. Gilliam, John W. Olive, and Emmett L. Carden
Root Control Bags, produced by Root Control of Oklahoma
City, can help nursery producers save more of a tree's roots at
harvest, but consumers prefer traditional plastic containers over
these "grow-bags." Some producers transplant trees from grow-
bags to containers to provide a more desirable product, but limited
data are available on how such transplants affect the trees.
With traditional field production, 92 to 98% of the root
system is reportedly lost when plants are harvested. Reports
indicate that more roots are harvested from a grow-bag. The grow-
bag system constricts the root tips as they penetrate through the
small holes in the fabric, resulting in root pruning and root
branching. As with a container, grow-bags confine a large portion
of the roots within a limited space. This positive aspect of grow-
bags for some trees facilitates year-round harvesting. Landscap-
ing has become a year-round business with demand for plant
materials that will tolerate transplanting during extremely stress-
ful conditions.
AAES research compared tree growth of traditional field
production and grow-bag systems in the sandy soils of south
Alabama where traditional field-harvesting methods are more
difficult. Performance of trees transplanted from the two field
production systems to 20-gallon containers in March (dormant
trees) and July (actively growing trees) also were compared.
The study indicated that grow-bags offer an alternative to
producing more difficult-to-transplant species, especially in sandy
soils where traditional field production is not practiced. Advan-
(Continued after photo section)
Phvii 1. Reduction in height of Kees Nelis tulip s% ith an ancx midof drench or
increasinig rates~ of paclohutrazoI in an impregnatedl spike. See article on
Page 2.
Photo 2. Brailian verbena
grow~n und~er long davs. left,
or shfort da.Ns 92 days' after
so ing. See rtleon P'age 3.
l'Ihoio 4. Pa.nsies in the
\l-Amnerica Displa%
Giarden at the EA'.
'F Smiith Research Center
q n alla',see. See article
*~ ~ on Page 4 for more
L'11%t i0I4II 1kj-II[M M1(11C 11a
P11010tr '090 r 10I IMto I)II01.Ih COt th~fl
Nlefod N% [lite Blotch in for egroundf.
coimpared to Roe White in background.
Phoo 0. I looi ig kale F eathier N hlte halt
miimal~r cold damlfage in Februar. 1992'.
compared to the other N hite %arielies.
Floral ShoN% ers Scarlet in N arch 1992: nrrrst loral
Carpet Red (background) died in earlY No% ember.
0zm 'Ol T,~g
4t
SPhotos 9. 10. AXh)ose l eft to right, salI% i treatIed iith 10,. I5, a nd 2 0
ppmn Sn mag ic; 5,0041) pm I It - N ine; and a n u uPt reated cont 
rol. Bie lostr
left to right, marigold treated %Nrith 10, I5. and 20 ppmn Sumagic;
i vi ~ A lb5,000 
ppm It-Nine; and an untreated control. See article 
on PageS.
P'hoto 8. C oreo psis %%as piroducred 1) the greatest iiuiii ol~e perenonial planit
producers shoresponded to a national surey.s See article tin Page 6.
- intainer, stold under
-~~' tp 4(at. trail, oc name E~n' ironmen-
7 illc Ilos * F riendlN
/,C S t '~ontainer F F U. See
idice tin P)age 16.
Phiitii 11. Suhirrigation of pear and pecan trees. See article on Page 16.
'ito 13. Bradfhrd pear
i es in, let toi right.-
ttI i r aditina 
I drip, raised
hole (E', and pali .
-N oh'irrigation li',Scc0 lt i
s1ic 16P
v
Phto 14. \I ieu-1 i list oak.~ lull. dct Ni sul li-iinspkinted in
Jl~ iiiiiiompiired to bag-ti iiispilutiieliis i right) si hh siirs ued
and gress . Sec article on Page IS.
11!
IT~
ii
I'Iiiitiis 15. 16. In the photo at left are Bradlford pears treatedl %%ith 150. 300. and 450 ppn B\ anid an lltreated control (iett to right ). In the photo at right
are Blrdtford pears treated Nwith 300. 600. and 1,2001 ppm Proailin. and an untreated control (left to right). See article on Page 22.
/
'1
Photo I7. Pepperminin t (ooler %inca grow ing on an ch a 11( fl Ib ench;
closest row% inoculated w ith I'vfoplrtlrora parasitica. See article on Page 30.
Photo I8. (os uinners participating in thle p~ottinig in v% .iluitiouu ,eclect their
plants at the heg inning of' a stud of(t a new% Iotti ng ledia that contains
comlposted chicken litter. See article on Page 410.
II ai.
AL.
21
t ages gained from using the grow-bags vary with the species
grown. One major limitation to the system is that no standards or
specifications for grow-bags have been developed by the Ameri-
can Association of Nurserymen for landscape architects and
designers to use in their plans. This failing hinders the market
potential of grow-bags.
METHODS
Liners of Lagerstroemia x Natchez (Natchez crape myrtle),
Pistacia chinensis (Chinese pistachio), and Quercus virginiana
(live oak) were transplanted on March 24, 1988, into the 20-gallon
containers. Live oak was selected because of its reputation for
being difficult to transplant, while crape myrtle is a tree that
traditionally transplants easily.
Tree liners were planted in a fine sandy loam soil at the Gulf
Coast Substation in Fairhope. Crape myrtles and live oaks were
planted in either 18-inch diameter grow-bags, backfilled with
native soil or by direct planting in the field. Holes were dug using
a 20-inch auger. Each tree was topdressed with one tablespoon (18
grams) of Osmocote 17-7-12 (Grace-Sierra Horticultural Prod-
ucts Inc., Milpitas, Calif.) at planting and again on April 13, 1989.
On July 21, 1988, and May 12, 1989, one tablespoon of 12-6-6 was
applied. Plants were watered every 28 hours for two hours with
drip irrigation emitters supplying two gallons of water at each
irrigation. Irrigation was turned off during rainy days.
A three-foot-wide weed-free strip was maintained around the
trees using metolachlor (Dual, Ciba-Geigy, Greensboro, N.C.)
and simazine (Princep, Ciba-Geigy, Greensboro, N.C.) at labeled
rates in April of each year. Spot-spraying as needed with glyphosate
(Round-up, Monsanto, St Louis, Mo.) and hand weeding around
the trunks of trees completed the weed control program. Plants
were spaced six feet within rows and 10 feet between rows.
Height and caliper were measured on Oct. 17, 1988, and
March 1, 1990. Calipers for crape myrtle were measured and
reported by taking the average of the largest three trunks of the
multi-stemmed trees. On March 17, 1990, one tree from each
block and treatment (24 trees, 12 of each species) was selected at
random and harvested. A 20-inch diameter root ball was hand-dug
for 5.8-foot crape myrtles and 1.4-inch caliper live oaks. Grow-
bag-grown trees were removed from the field in their bags. The 24
trees were cut at ground level and fresh top weight was deter-
mined. Root balls were washed, roots were severed from the
original root ball, and fresh root weight was recorded.
Two additional trees from each block and treatment (24 trees
of each species) were hand-dug and transplanted to 20-gallon
containers filled with a 100% pine bark medium (grow-bags were
removed from trees). Trees were fertilized by topdressing with 5.3
ounces per pot of Osmocote 17-7-12 plus minor nutrients. Trees
were placed under 50% shade, syringed three to four times a day
for one week, and then moved to the production area under
overhead irrigation.
On July 11, 1990, four months after transplanting, container-
ized trees were measured for caliper, height, and fresh weight.
Twelve root balls of each species were slipped from the containers
and the percent of the root ball surface covered with roots was
evaluated. Root balls were given ratings from 1 to 5 (see tables).
Oak roots were washed, and root growth extending into the pine
bark from the severed roots of the original root ball were cut and
weighed. Crape myrtle root systems were too dense to separate the
container medium from the roots.
On July 11, the remaining 24 trees (12 of each species) were
measured, dug, and transplanted to 20-gallon containers using the
same procedures described earlier. This step was used to evaluate
transplanting success during stressful conditions. The July-planted
containerized trees were harvested Oct. 3, 1990, and fresh weight
and root ratings were recorded.
RESULTS
Growth was similar for both tree species grown in both tree
production systems (see tables on next page). Exceptions were
1990 live oak height and 1988 live oak caliper where trees (60
measured) in traditional field production were seven inches taller
than trees grown in grow-bags and 0.04 inch larger in caliper,
respectively. However, this difference was not reflected in the
other growth variables, and the difference was very small. This
agrees with most other research on grow-bags.
Neither caliper nor top weight of crape myrtles or live oaks
differed as a result of transplanting the dormant trees to containers
in March, 1990. However, live oaks and crape myrtles produced
without bags, dug by hand, and grown in containers for nine
months were 16.5 and 6.7 inches taller, respectively, than trees
grown in grow-bags. Live oak root regeneration expressed by the
root rating was enhanced when plants were grown in grow-bags.
Growth was similar for March-transplanted/July-harvested
and July-transplanted/October-harvested crape myrtles when com-
paring grow-bag and traditional field production. Live oaks pro-
duced by traditional field production and transplanted to the 20-
gallon containers in July died. Live oaks grown in grow-bags
survived and continued to grow until the October harvest. Addi-
tional root growth was exhibited by trees grown in grow-bags
which were March-transplanted/July-harvested (root rating 3.5)
over traditional field-produced trees harvested and transplanted
on the same dates (root rating 2.6). This result may help explain
the survival of July-transplanted live oaks from grow-bags in
October and the death of traditional field-produced trees.
A niche has been established in the industry for the produc-
tion and use of plants produced in grow-bags. Grow-bags meet a
need for trees by landscapers in mid-summer. As evidenced by the
results from transplanting crape myrtles, all trees may not benefit
from the grow-bag system. The system is a hybrid between
traditional field production and container production and requires
developing cultural and marketing practices that are significantly
different from the other two systems. This research and that of
others shows that many plants can be grown as well in grow-bags
as by traditional field production methods. Live oaks and possibly
other difficult-to-transplant trees can have increased success in
the landscape when produced in grow-bags, especially where
sandy soil conditions prevail. See Photo 14 on Page 20.
Tilt is Associate Professor and Gilliam is Professor of Horticulture;
Olive and Carden are Superintendents of Ornamental Horticulture and
Gulf Coast Substations, respectively.
22
Table 1. Effects of Production System on Crape Myrtle Harvested from the Field and Transplanted to Containers
Field
Caliper' Height' Top fresh weight' Root weight'
1988 1990 1988 1990 1990 1990
mm mm cm cm kg g
Field ............................................................. -2 23 105 175 2.4 276
Grow-Bag ............................................................. 28 105 
176 2.6 353
Container
Caliper' Height' Top fresh weight' Root Rating
3
July Oct. July Oct. July Oct. July 
Oct.
mm mm cm cm kg kg
Field ..................................... 29 32 206 193 3.9 4.7 4.3 4.1
Grow-Bag ......................... 29 31 189 178 4.1 3.3 
4.1 4.0
Table 2. Effects of Production System on Live Oak Harvested from the Field and Transplanted to Containers
Field
Caliper' Height' Top fresh weight' Root weight
1988 1990 1988 1990 1990 1990
mm mm cm cm kg g
Field ..... ............................ 16 36 132 211 2.2 262
Grow-Bag ............................. 15 36 127 193 2.0 260
Container
Caliper' Height' Top fresh weight' Root Rating
3
July Oct. July Oct. July Oct. July 
Oct.
mm mm cm cm kg kg
Field ..................................... 47 -2 252 - 3.1 - 2.6-
Grow-Bag ............................ 43 44 210 211 3.3 2.5 3.5 
2.5
'One millimeter (mm) is .0394 inch. One centimeter (cm) is .3937 inch. One kilogram (kg) is 1,000 grams (g). One gram is .035 ounce.
2
Data not available.
3
Trees were transplanted to 20-gallon containers from the field in March 
and July, 1990 and harvested in July and October. Root rating: 1= 
No roots on outside of
container rootball, 5= matted (24 trees each species, each transplant date).
Increasing Crotch Angles and Lateral Shoot Numbers of Bradford Pear with BA 
or Promalin
Gary J. Keever, William J. Foster, and John W. Olive
Bradford pear, a widely planted ornamental tree, is character-
ized by an oval-to-pyramidal form and dense, ascending branches.
With age, many symmetrical specimens split, presumably due to
narrow, bark-embedded crotches that are structurally weak com-
pared to crotches with connective wood. Pruning during produc-
tion in the nursery to remove narrow crotches and increase branch
spacing has met with limited success in alleviating splitting.
Growth regulators, such as the cytokinin benzyladenine (BA)
used alone or in combination with gibberellins4+
7 
(Promalin), have
improved plant structure of several fruit tree species by stimulat-
ing branching and increasing the crotch angles of primary branches.
An AAES study was conducted to determine the effects of foliar-
applied BA and Promalin on branching and crotch angles of
Bradford pear.
Results support previous research findings with fruit tree
species, where increased lateral shoot development and crotch
angles and reduced lateral shoot length resulted from BA or
Promalin treatment. This work indicates that BA and Promalin
can increase crotch angles of Bradford pear, which potentially
could lessen the splitting of older trees. Increased lateral develop-
ment may require selective pruning to avoid crowding of branches
as trees mature.
METHODS
Liners (nine inches tall) of Bradford pear were trans-
planted on March 22, 1988, into three-gallon pots of 3:1 pine
bark:peat moss (by volume) amended with six pounds dolomitic
limestone, two pounds gypsum, 1.5 pounds Micromax, and 14
pounds Osmocote 17-7-12 per cubic yard. Plants were placed
outdoors in full sun in Mobile and maintained under overhead
irrigation. On Sept. 20, 1988, plants were pruned to 51 inches in
height, and leaves were left on only the uppermost 10 nodes. The
following foliar spray treatments were applied to the upper 12
inches of shoots: 150-450 milligrams of BA per liter or 300-900
milligrams of Promalin per liter with Buffer X surfactant at 0.2%
by volume. An untreated control was included for comparisons.
Plant height, lateral shoot numbers (greater than 0.8 inch in
length) and lengths, and crotch angles were recorded on Nov. 18,
1988. The experiment was repeated in 1989 with the following
changes: liners were transplanted on April 20, treatments were
applied Sept. 12, only the upper three inches of terminal shoots
were removed, BA at 600 milligrams per liter and Promalin at
1,200 milligrams per liter were included as additional treatments,
and data were collected in December 1989.
23
RESULTS Effects of BA
Lateral shoot numbers and crotch angles
were increased in both years 
with increasing Treatment'
concentrations of BA or Promalin (see table).
The increase in shoot number was 65-440% mg/1
(1988) and 43-174% (1989) with BA con- Control
centrations greater than 
or equal to 300 mil- 
0......................
ligrams per liter, and 240-490% (1988) and 150...................
43-239% (1989) with Promalin concentra- 300..........................
450 .....................
tions greater than or equal to 300 milligrams 600 ..........................
per liter. Almost all new lateral shoots devel- Promalin
oped from the 12-inch 
section of shoot treated 
300 ..........................
600 .........................
with BA or Promalin. Crotch 
angles were 900.........................
increased 26-30% (1988) and 10-26% (1989) 
1,200 ......................
with BA and 26-34% (1988) and 6-38% 'One milligram (mg)
(1989) with Promalin. Promalin 
resulted in 
2
Shoots greater than 0
greater shoot numbers 
(9.6 versus 5.3, 
1988; 
3
One centimeter (cm)
4.9 versus 3.9,1989) and crotch angles (580 versus 520, 1988) than
did BA. Mean lateral shoot lengths decreased linearly in 1989
with increasing concentrations of the growth regulators, from 9-
23% with BA and 15-57% with Promalin. The reduction was most
evident for BA and Promalin at concentrations greater than or
equal to 450 milligrams per liter and 900 milligrams per liter,
and Promalin on Primary Shoot Development of Bradford Pear Trees
Lateral shoots
2  
Crotch angle Shoot length
3
1988 1989 1988 1989 1989
no. no. cm
........ 2.0 2.3 450 460 11.1
........ 1.8 2.3 420 510 10.1
........ 3.3 3.3 570 500 10.7
...... 10.8 3.5 580 590 6.9
........... - 6.3 - 58 8.6
........ 6.8 3.3 570 490 9.4
...... 10.3 2.8 580 490 10.8
...... 11.8 6.0 600 610 6.1
.... 7.8 - 630 4.8
is .001 gram; one gram is .035 ounce. One liter (1) is 1.0567 liquid quarts.
).8 inch in length were counted.
is .3937 inch.
respectively. Mean shoot lengths of BA- and Promalin-treated
trees were 3.6 inches and 3.1 inches, respectively, while lateral
shoot length of control plants averaged 4.4 inches. Plant heights
were not affected by any treatments. (See Photos 15-16, Page 20)
Keever is Professor of Horticulture; Foster is former Superintendent
and Olive is Superintendent of the Ornamental Horticulture Substation.
Response of Established Landscape Plants to Uniconazole
Gary J. Keever
Much of the millions of dollars spent each year on landscape
maintenance and tree-trimming under power lines could be saved
through the use of the right plant growth regulator. Many of these
compounds have been evaluated for retardation of woody plant
growth, but most are not economical or cause undesirable side
effects.
Uniconazole (Sumagic), a triazole-based growth regulator,
has shown promise for being very persistent in retarding growth
without harming the plant. It is labeled for use on bedding plants
and several potted crops, but not on woody landscape plants.
Research indicates that uniconazole is effective in suppressing
growth of container-grown woody landscape plants, but its influ-
ence on field-grown landscape plants had not been studied.
Another concern was that the previous studies with con-
tainer-grown woody ornamentals were done with "angiosperms,"
such as maple, oak, and holly. However, growth retardants are
generally less effective or harmful to "gymnosperms," such as
pines, cedar, and juniper.
AAES research was conducted to determine the influence of
soil- and foliar-applied uniconazole on two established, field-
grown woody landscape species under simulated low mainte-
nance landscape conditions. Both species, Elaeagnus pungens
Fruitlandii (thorny elaeagnus), an angiosperm; and X
Cupressocyparis leylandii (leyland cypress), a gymnosperm, ex-
hibit very fast growth rates. Preliminary tests were performed to
establish approximate rates of uniconazole for gymnosperms.
Drench-applied uniconazole was shown to be effective in
retarding growth of in-ground thorny elaeagnus for at least two
growing seasons under landscape conditions. This material could
offer those involved in landscape maintenance an additional tool
for managing this vigorous species. Regular, but less pruning will
still be required to remove rank shoots. Foliar spraying of
uniconazole to established thorny elaeagnus was ineffective in
retarding shoot growth. Uniconazole was effective in retarding
growth of young, container-grown leyland cypress, but it was not
effective when applied as either a foliar spray or drench to
established plants under landscape conditions.
METHODS
To establish rates of uniconazole for gymnosperms, uniform
liners of leyland cypress in four-inch containers were potted into
No. 1 gallon containers using a pine bark:sand (7:1, by volume)
growth medium amended per cubic yard with five pounds dolo-
mitic limestone, 14 pounds Osmocote 17-7-12, and 1.5 pounds
Micromax in Jan. 1989. Plants were grown in a heated (minimum
68
0
F) double polyethylene greenhouse. On March 31, 1989,
uniconazole was applied as a foliar spray or drench. Single foliar
sprays of 10-500 milligrams per liter was applied using a hand-
held sprayer to uniformly wet foliage and stems. Single medium
drenches of 1-15 milligrams of active ingredient per pot was
applied in a volume of one ounce.
Growth indices (see table footnotes for definition) measured
six weeks later were inversely proportional to uniconazole rates,
regardless of application method. Growth indices of plants sprayed
with the 200 or 500 milligrams per liter rate of uniconazole were
18% and 37% smaller, respectively, than those of control plants.
Reduction in growth indices with drench application ranged from
7% with the five-milligram drench treatment to 48% with the 15-
milligram drench treatment. Based on these results, rates higher
than those that suppressed shoot growth were selected for the in-
ground experiment to test if older, well-established landscape
24
plants would be less responsive to uniconazole.
The experimental site for the field test consisted of a Marvyn
loamy sand soil of pH 5.5. Based on soil test recommendations,
dolomitic limestone was broadcast over the planting area at 2,000
pounds per acre. The area was subsoiled to an 18-inch depth in the
rows, and planting holes were cored to 24 inches with a 24-inch
auger. Uniform No. 1 gallon plants of thorny elaeagnus and
leyland cypress were planted on Dec. 4, 1988. Plants were spaced
four feet apart within rows, and rows were six feet apart. Plants
were pruned for shape on May 3, 1989, and for uniformity (24x24
inches) on April 12, 1990. Osmocote 17-7-12 at one tablespoon
per plant was topdressed around the base of each plant on May 18,
1989, and April 16, 1990. Area between plants was maintained by
periodic mowing and the use of glyphosate (Roundup). No supple-
mental irrigation was provided.
On April 12, 1990, the following uniconazole treatments
were applied to both species: single drench applications of 15-45
milligrams of active ingredient in 17 ounces of distilled water
applied around the base of each plant; single foliar sprays of 500-
1,500 milligrams per liter solution applied to uniformly wet
foliage and stems; and an untreated control. Spray treatments
were applied using a CO
2 
sprayer with a No. 3 conical head nozzle.
Tank pressure was 20 pounds per square inch, and about six
ounces of solution were applied to each plant. Climatic conditions
when treatments were applied were clear, 55'F, and 76% relative
humidity.
Growth indices were measured on July 18, 1990; Dec. 6,
1990; and Dec. 10, 1991 (leyland cypress only). On Dec. 18, 1991,
half of the thorny elaeagnus in each treatment were cut at ground
level, chipped using a portable shredder, and placed in a 158'F
drying oven for 21 days before being weighed. Shoot dry weights
of leyland cypress were not determined because plants appeared
uniform in size and density.
RESULTS
Growth indices of elaeagnus were not affected by uniconazole
rate when measured in July 1990, although there was a slight
downward trend with increasing drench rates (see the table).
Mean growth indices of drench-treated plants (90.0) were signifi-
cantly less than those of sprayed (102.5) or untreated plants (97.7).
By December 1990, growth indices were similar among plants
treated by the different application methods.
Shoot growth of thorny elaeagnus plants was relatively uni-
form during the two months following pruning. Plants developed
vigorous, rank shoots during the latter part of the 1990 growing
season and the entire 1991 growing season that made growth
indices a poor indicator of vegetative growth after mid-summer
1990, hence shoot dry weights were determined in December
1991. Shoot dry weight of thorny elaeagnus decreased with
increasing rates of drench-applied uniconazole. Weight of plants
receiving 15, 30, or 45 milligrams of active ingredient per plant
were 16, 37, and 61%, respectively, less than those of control
plants. Drench application resulted in significantly lower mean
shoot dry weight than spray application (six pounds versus 9.2
pounds) or than no treatment (9.7 pounds). Weights were not
affected by increasing rates of foliar-applied uniconazole. Growth
indices of leyland cypress were not influenced by application
method or rate on any of the sampling dates. All plants were
densely pyramidal in form and uniform in appearance.
No phytotoxicity or foliar color differences were observed on
plants of thorny elaeagnus or leyland cypress in any treatment
during the experiment. Flowering of elaeagnus in fall 1990 ap-
peared heavier on plants receiving a drench application of
uniconazole compared to those sprayed, and heavier on plants
sprayed with 1,500 milligrams per liter than on those sprayed with
a lower rate or not treated. No quantitative measurements of
flowering were made.
Effectiveness ofuniconazole in controlling vegetative growth
of elaeagnus was greater with drench application than with foliar
application. This is likely due to differences in root and foliar
uptake of uniconazole or differences in the compound's ability to
be moved in different parts of the plant.
Shoot growth of leyland cypress, a gymnosperm, was not
affected by uniconazole applied as either a spray or a drench.
Shoot dry weight of thorny elaeagnus, an angiosperm, was re-
duced as much as 61% with a single drench application.
In a short-term test with recently-potted liners of leyland
cypress, plants were as much as 37% or 48% smaller than control
plants when treated with a foliar spray or drench application,
respectively, of lower concentration than that used in the field test.
Differences in effectiveness may relate to plant age, growing
environment, or both. In other research, young gymnosperm
seedlings responded to drench application of several growth
retardants, while older plants (three to nine years old) were not
affected by soil drench or stem injection of the growth regulator.
Plants in this field test were well-established, having been planted
16 months prior to treatment. Soil-applied triazole retardants are
relatively immobile and are most efficiently taken up by plants
when both roots and inhibitor are localized in the same area.
Essentially the entire root systems of container-grown leyland
cypress were exposed to uniconazole, while a relatively smaller
portion of the root systems of field-grown plants were treated.
Response of Thorny Elaeagnus to Drench or
Foliar Applied Uniconazole (Sumagic)
Treatment Growth index
1 ,2  
Shoot dry wt.
3
7/18/90 12/6/90
cm cm kg
Drench
4
15 .......................................... 92.3 150.6 3.68
30 .......................................... 93.2 174.2 2.76
45 .......................................... 87.2 154.0 1.71
Foliar
5
500 .................................... 98.1 153.6 4.32
1,000 ............................... 106.8 158.0 4.08
1,500 ................ 102.5 153.2 4.17
0.. .................. .................. 97.7 151.3 4.38
1
Growth index = (height + width
1 
+ width
2
)/3. Width
1 
was at the widest point, and
width
2 
was perpendicular to width
1
.
lOne centimeter (cm) is .3937 inch.
3
One kilogram (kg) equals 2.205 pounds. Weight was measured on Dec. 18,
4
Sumagic measured in milligrams of active ingredient per plant. One milligram
is .001 gram; one gram is .035 ounce.
5
Sumagic measured in parts per million.
Keever is Professor of Horticulture.
IVICil.ll~l~~WI.II IIIILICTS I!I ILITII~;II-IITil It~(l III illllSIrlll~lWt~lt: SI~IIIII-
25
Controlled Release Fertilizers Influence Container-Grown Azaleas
D. Joseph Eakes, John W. Olive, and Patricia R. Knight
Resin-coated controlled release fertilizers (CRFs) are gener-
ally formulated to operate in temperatures much lower than those
actually measured in the South during summer. Higher tempera-
tures hasten the release of nutrients with possible negative conse-
quences for plants.
Release of nutrients from these materials is controlled by the
resin coating thickness, medium moisture content, and most
importantly, medium temperature. Manufacturers generally docu-
ment nutrient release characteristics for their CRF products at
temperatures ranging from 68 to 77
0
F. However, container tem-
peratures often exceed 95
0
F for during the summer. An AAES
study compared 12- to 14-month CRFs at four rates on growth of
three azalea species.
Greatest shoot dry weights for the three species occurred with
the highest N application rate, three pounds of N per cubic yard,
regardless of CRF product applied. Coral Bells azalea was the
only species influenced by CRF product 360 days after treatment.
Greatest shoot dry weights occurred for the Nutricote- and
Osmocote-treated plants.
METHODS
Uniform liners of Rhododendron obtusum Coral Bells (kurume
type), R. indicum Formosa (southern indian type), and R.
eriocarpum Pink Gumpo (Satsuki type) were potted May 2, 1990,
in a 3:1 pine bark:peat moss medium in trade gallon containers.
Fertilizer treatments were Osmocote 17-7-12, Sierra 16-6-10,
High-N 24-4-7, Sierrablen 17-7-10, and Nutricote 16-10-10 (Type
360) preplant incorporated from 1.5 to three pounds of nitrogen
(N) per cubic yard. All media were amended with six pounds of
dolomitic limestone, two pounds of gypsum, and 1.5 pounds of
Micromax per cubic yard, with the exception of the Sierra 16-6-
10 medium where no Micromax was added.
Medium leachates were collected at 30-day intervals up to
360 days after treatment using the Va. Tech. Pour-through Extrac-
tion Procedure to determine medium solution electrical conduc-
tivity (EC). On Jan. 4, 1990, half the plants were harvested to
determine shoot dry weight. The remaining plants were harvested
to determine shoot dry weight on May 6, 1991.
RESULTS
Shoot dry weights increased as N rate increased for the three
azalea species in 1990 and 1991, regardless of CRF applied.
Greatest shoot dry weights for Coral Bells azalea were produced
by the Osmocote and Sierrablen treatments during the 1990
growing season (see table). Following the 1991 spring flush of
growth, Nutricote plants had the greatest shoot dry weights
compared to the other CRF treatments, while shoot dry weights
for Sierrablen treated plants were the least.
Formosa azalea shoot dry weight was greatest for Sierrablen-
treated plants in 1990, regardless of application rate. Osmocote-
, High-N-, and Sierrablen-treated plants were similar in size to
Sierrablen-treated plants, while Nutricote-treated plants had the
smallest shoot dry weight when compared to other CRF treat-
ments. Following the 1991 spring growth flush, there was no
difference in shoot dry weight due to CRF for Formosa azalea.
Greatest shoot dry weight for Pink Gumpo azalea in 1990
occurred for Osmocote- and High-N-treated plants, regardless of
fertilizer rate. As with Formosa azalea following the 1991 spring
flush of growth, CRF product had no influence on shoot dry
weight for Pink Gumpo azalea.
Electrical conductivity is a measure of the quantity of fertil-
izer salts in the soil; as EC drops, fertilizer quantity declines.
Thirty days after treatment, Nutricote had the greatest medium
solution EC level with a mean EC of 0.60 decisiemens (dS) per
meter. The lowest EC levels were observed for Osmocote and
Sierrablen with EC levels of 0.24 and 0.21 dS per meter, respec-
tively. From 30 to 60 days after treatment, medium solution EC
increased for all CRF treatments with the exception of Nutricote.
Medium solution EC was greatest for the High-N and Sierra
products 60 days after treatment, while Nutricote had the lowest
EC; a sharp decrease from 30 days after treatment. Medium
solution EC levels increased from 60 to 90 days after treatment for
the Osmocote and Sierra products, while Nutricote, High-N, and
Sierrablen all had decreases in EC. Medium solution EC declined
for all CRFs from 90 through 360 days after treatment.
Medium solution EC levels began to drop sharply 90 days
after treatment for all treatments. Medium solution EC increased
as application rate increased. Following observations 90 days
after treatment, EC declined for all fertilizer rates. By 150 days
after treatment, mean medium solution EC across all treatments
and rates was 0.14 dS per meter and continued to decline to 360
days after treatment.
Eakes is Assistant Professor and Knight is Graduate Research Assis-
tant of Horticulture; Olive is Superintendent of the Ornamental Horticul-
ture Substation.
Shoot Dry Weight for Three Azalea Species in Response to 12- and 14-Month Controlled Release Fertilizers and Rate of Application
Treatment Shoot dry weight'
1990 1991
Coral Bells Formosa Pink Gumpo Coral Bells Formosa Pink Gumpo
g g g g g g
Fertilizer
Osm ocote ........................................................... 42.6 70.5 36.7 48.1 80.5 58.2
Sierra ....................... ..... ......................... 34.6 72.8 33.3 41.4 80.8 52.9
H igh-N ............................................................. 35.2 68.1 36.9 45.8 77.6 54.9
Sierrablen ........................................................... 38.3 68.7 34.7 44.2 78.9 49.8
Nutricote ........................................................... 36.2 64.9 31.5 50.7 77.2 53.3
Rate
2
1.5 ................... . ...................... 30.5 54.3 29.9 38.1 60.2 42.5
2.0 .................... . ...................... 36.8 62.3 32.3 43.7 76.3 50.7
2.5 .................... . ...................... 37.4 75.3 37.9 49.5 88.2 58.3
3.0 ........................................... 44.9 84.1 38.3 52.9 91.4 63.8
'One gram is .035 ounce. 
2
The rates of application are measured in pounds of N per cubic yard.
26
CRF Type, Rate, and Placement Influence Growth of Container-Grown Ornamentals
D. Joseph Eakes, John W. Olive, and Charles H. Gilliam
Controlled release fertilizers (CRFs) are an integral part of
the fertilization programs of many container-grown nurseries.
Plant growth and nutrient release characteristics vary depending
on method of fertilizer application, CRF product, fertilizer rate,
and plant species grown.
Effects of applying CRFs at three nitrogen (N) rates on the
growth of juniper and azalea were assessed in an AAES study.
Research showed that CRF type had little effect on the growth of
juniper, but best results were obtained when CRF was preplant
incorporated at 2.5 pounds of N per cubic yard. However, dibble
fertilizer placement of more than 1.5 pounds appeared to injure
roots, reducing growth of juniper. In contrast, dibble and topdress
applied Osmocote and Nutricote, at the rate of 2.5 pounds per
cubic yard, produced the greatest azalea shoot dry weight. CRF
type and rate did not affect azalea root ratings.
METHODS
Uniform liners of Juniperus conferta Blue Pacific (juniper)
and Rhododendron x Coral Bells (azalea) were potted May 16 in
trade gallon containers of a 3:1 pine bark:peat moss medium. The
medium was amended with six pounds of dolomitic limestone,
two pounds of gypsum, and 1.5 pounds of Micromax per cubic
yard. Fertilizer treatments were Osmocote 18-6-12, Nutricote 16-
10-10 (Type 270), and High-N 24-4-8. All CRFs are eight- to
nine-month formulations. Application methods were preplant
incorporated, dibbled, or topdressed at 1.5, 2.0, or 2.5 pounds of
N per cubic yard. In November, juniper and azalea shoot dry
weights and relative root densities were determined.
RESULTS
Shoot dry weights and root ratings for juniper receiving
dibble-applied fertilizer were greatly reduced as N rate increased
regardless of the CRF used (Figures 1 and 2). Dibble placement of
CRFs at the rate of 1.5 pounds of N per cubic yard produced plants
that had 57% and 38% more shoot dry weight than those receiving
two and 2.5 pounds of N per cubic yard, respectively. In contrast,
when fertilizer was incorporated into the medium or topdressed,
shoot dry weights and root ratings of juniper generally increased
as N rate increased. Shoot dry weights and root ratings were not
influenced by CRF type.
Azaleas that were topdressed or dibbled with CRFs had 31%
and 27% greater shoot dry weights than those receiving preplant
incorporated fertilizers, respectively (Figure 3). Both Osmocote
18-6-12 and Nutricote 16-10-10 resulted in greater azalea shoot
dry weights than plants receiving the High-N 24-4-8 fertilizer.
Shoot dry weights of azalea increased as N rate increased for all
CRF products and method of application.
Root densities were rated on a scale of 1-5, with 1 = no visible
roots and 5 = 100% of the root ball medium-container interface
covered with roots. Root ratings of azalea were 3.9 and 3.8 with
dibbled and medium incorporated fertilizer placement, respec-
tively (Figure 4). In comparison, plants receiving topdressed
fertilizer placement had a mean root rating of only 3.5. Root
ratings were not affected by CRF type or rate.
Eakes is Assistant Professor and Gilliam is Professor of Horticulture;
Olive is Superintendent of the Ornamental Horticulture Substation.
Figure 1. Juniper Shoot Dry Weight
Grams
60 r- 1gg 1.51b. N
50 - 2.5b. N
40-
30
20
10
Dibble Incorporated Topdressed
Fig. 1. Shoot dry weight of juniper as influenced by controlled
release fertilizer rate and placement.
Figure 2. Juniper Root Rating
Rating
6 - 1 
1.5 lb. N
21lb. N
5 -
2.5 lb. N
4 -
3 -
2
i -
0 Dibble Incorporated Topdressed
Fig. 2. Root quality rating of juniper as influenced by controlled
release fertilizer rate and placement.
Figure 3. Azalea Shoot Dry Weight
Gra
40-
30
20
10
n
ms
- Rate Fertilizer Method of Applic
=nHH
4. 4+4.
ro.4- .4- .4
O 4 +
0 + CEO,
ono
O~'6 
0
/l0 pips
coq
Fig. 3. Shoot dry weight of azalea as influenced by controlled
release fertilizer rate, type (Osmocote 18-6-12, Nutricote 16-10-10, or
High-N 24-4-8), and placement.
Figure 4. Azalea Root Rating
Ra
5-
4.
3
1
n
ting
Rate Fertilizer
junpe .111in
*4- 4- - %
Method of Application
'% ? e
4 o 
~Q o 
ssO9
SFig. 4. Root quality rating of azalea as influenced by controlled
release fertilizer rate, type (Osmocote 18-6-12, Nutricote 16-10-10, or
High-N 24-4-8), and placement.
..... ... ... ..
1 . 1 i, 1 . . r 11 ___1 '0,
-
-
27
INSECT, DISEASE, AND WEED CONTROL
Evaluation of Postemergence-Applied Herbicides on Ornamental Grass
Charles H. Gilliam, Gary J. Keever, Donald J. Eakes, and Donna C. Fare
Demand for ornamental grasses in landscaping in on the rise,
but competition from annual and perennial grasses can cause
problems. Ornamental grasses are tolerant to some postemergence-
applied herbicides, though tolerance varies among species. A
study was conducted to evaluate the effects of two registered
postemergence-applied herbicides, Poast (sethoxydim) and
Fusilade (fluazifop), for over-the-top application on ornamental
grasses.
Poast and Fusilade have undergone extensive evaluation for
use in landscape plantings and are registered for a wide range of
landscape plants for the control of annual and perennial grasses.
In addition, Poast is registered for selective use in some turf
species. Neither Poast nor Fusilade is registered for use on
ornamental grasses, and information is lacking on the response of
ornamental grass species to these herbicides.
Data from the study show that use of these herbicides will
injure ornamental grasses. The extent of injury varies with species
and with choice of herbicide. In extreme situations weed pressure
may dictate use of a postemergence-applied herbicide. Growers
and landscapers should evaluate the tolerance of ornamental
grasses on a small scale before adopting widespread use of a
particular herbicide. These data indicate that Poast was generally
the least injurious to ornamental grasses. Use of Fusilade was
injurious to all grasses tested.
METHOD
Liners of four ornamental grasses: dwarf fountain grass
(Pennisetum alopecuroides Hameln); pampas grass (Cortaderia
selloana); maiden grass (Miscanthus sinensis Gracillimus); and
purple maiden grass (M. sinensis Purpurescens) were potted into
#1 plastic containers on May 23, 1990. The medium was pinebark/
sand (6:1, by volume) amended per cubic yard as follows: 14
pounds of Osmocote 18-6-12, five pounds of dolomitic limestone,
and 1.5 pounds of Micromax. All plants were grown in full sun and
irrigated as needed. Various herbicide treatments were applied on
June 19 to all four ornamental grasses (see tables). An untreated
weeded control treatment was included with each ornamental
grass for comparison. Broadleaf weeds were removed by hand
from all herbicide treatments. Herbicides were applied in 20
gallons of water per acre with a backpack CO
2 
sprayer using a
8004 nozzle operated at 30 pounds of pressure per square inch.
Ambient air temperature was 87oF with 75% relative humidity at
the time of application. Grass control data are not presented since
the activity of these herbicides is well documented.
In 1991, the study was repeated with the same species to
collect additional data, including flower number at the peak of
flowering 120 days after treatment for pampas, maiden, and
purple maiden, and 60 days after treatment for dwarf fountain
grass. Liners were potted in May, with medium and cultural
practices similar to the 1990 test. The same treatments used in the
first experiment were applied on May 16, 1991 (see tables). Plants
were larger in 1991 due to larger liners being planted.
RESULTS
Some injury occurred with both postemergence-applied her-
bicides on all grass species tested at some point in the two-year
evaluation (Table 1). In 1990, pampas grass displayed no differ-
ence in plant injury when comparing the unsprayed control plants
and plants treated with Poast at the low rate. Injury was generally
greater with the higher rates of the two herbicides and with
Fusilade compared to Poast. In both years, greater than 50% injury
occurred with both Fusilade 2000 rates on all four grasses 30 days
after treatment. With Poast, maiden grass (1990) and purple
maiden grass (1990 and 1991) had greater than 50% injury at the
low rate, while at the higher rate both miscanthus species and
dwarf fountain grass had greater than 50% injury 30 days after
treatment. Fusilade 2000 caused greater than 50% injury on all
four grasses 30 days after treatment when applied at the low rate.
These data concur with other reports that have shown Fusilade
causes injury to most grass species. By 60 days after treatment in
both years, most plants that survived the herbicide treatments had
initiated new growth and exhibited normal growth through the
remainder of the growing season.
Although initial growth was delayed or damaged, many of the
plants caught up with the untreated control plants before the end
of the growing season. These data concur with previous reports of
maximum injury occurring four weeks after application. Growth
indices of all grasses (both years), except purple maiden grass and
maiden grass in 1990, treated with .25 pound per acre of Poast
were similar to the untreated control grasses (Table 2). See Table
Footnote 6 for a definition of growth index.
Growth indices of all grasses treated with .50 pound per acre
of Poast tended to be smaller than the untreated control plants but
similar to or larger than growth indices of Fusilade-treated plants.
Fusilade 2000 limited growth of all grass species at the lower rate
except dwarf fountain in 1991, and the higher rate had lower
28
growth indices with all grasses.
Flowering in three of the four grasses was adversely affected
by all postemergence herbicide treatments in 1991 (data 
not
shown). The fourth grass, pampas, did not flower during the 1991
growing season. Poast at the low rate had a limited effect on
growth indices and reduced flowering 82% and 61%, respec-
tively, for maiden grass and purple maiden grass.
EDITOR'S NOTE: This paper reports the results of research
only. It does not imply registration of a pesticide. Before 
using any
of the products mentioned in this research paper, be certain of 
their
registration by appropriate state and/or federal authorities.
Gilliam is Professor, Keever is Professor, Eakes is Assistant 
Professor,
and Fare is former Senior Research Associate of Horticulture.
Table 1. Injury Caused by Selected Herbicides to Ornamental Grasses 
15 and 30 Days After Treatment in 1990 and 1991
Treatment
2  
Pct. visual injury
3
Pampas grass Dwarf fountain 
Maiden grass Purple maiden
1990 1991 1990 1991 1990 
1991 1990 1991
15 30 15 30 15 30 15 30 
15 30 15 30 15 30 15 30
Poast +.25% COC
4
0.25 .................................. 10 0 8 26 35 
9 46 45 22 71 42 36 61 
66 50 63
Poast +.25% COC
0.50 .................................. 34 34 26 34 53 48 
54 56 51 93 59 56 72 81 67 
78
Fusilade +.25% X-77
5
0.25 ..................................46 89 50 61 56 
76 29 52 30 92 50 61 69 
79 50 73
Fusilade +.25% X-77
0.50 .................................. 69 69 97 31 60 69 
94 46 73 41 98 58 81 91 61 
86
Weeded check
0 .......................................... 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 
0
Table 2. Effects of Herbicides on Growth Indices of Ornamental 
Grasses in 1990 and 1991
Treatmentl,
2  
Growth indices
6
,7
Pampas grass Dwarf fountain 
Maiden grass Purple maiden
1990 1991 1990 1991 1990 
1991 1990 1991
cm cm cm cm cm 
cm cm cm
Poast +.25% COC
4
0.25 .................................................. 85.2 136.8 
49.8 100.4 56.0 124.5 34.8 
69.6
Poast +.25% COC
0.50 ................................................. 62.9 130.2 
38.0 103.4 45.0 115.9 
30.2 62.0
Fusilade +.25% 
X-77
5
0.25 .............................. .................... 34.1 112.2 31.5 
95.4 46.3 68.4 28.7 64.2
Fusilade +.25% X-77
0.50 .................................................. 24.8 61.2 
26.6 50.5 44.7 54.6 23.1 
51.4
Weeded check
0 ....................................................... 88.1 137.3 
53.0 106.3 85.6 115.1 42.3 
80.6
'Treatments were applied on June 19, 1990, and May 16, 1991. Data 
were collected 15 and 30 days after treatment.
2
Rates are measured in pounds of active ingredient per acre.
3
Visible injury was rated on a scale of 0-100% with 0% = no injury and 100% = dead plant.
4
COC = crop oil concentrate (Prime Oil).
5
Ortho X-77, a nonionic surfactant.
6
Growth index = (height + width
1 
+ width
2
)/3. Width
1 
was at the widest point, and width
2 
was perpendicular to width . Data were taken 60 days after treatment (July
24) in 1990 and 90 days after treatment in 1991 (Aug. 21).
7
Growth index is measured in centimeters (cm). One cm is .3937 inch.
Evaluation of Preemergence-Applied 
Herbicides on Selected Hardy Ferns and 
Hosta
Daniel M. Lauderdale, Charles H. Gilliam, and John W. Olive
In the past few years, several herbicides have been registered
for use in nursery crop production. Some of these new herbicides
have been reported to be safer on container-grown crops than
some of the standard chemicals used in nursery production. 
A
study was conducted to compare several of the new products with
standard herbicides in terms of growth and injury to herbicide-
sensitive plants.
Results showed that the newly registered herbicides tested -
- including Pennant 5G, Derby 5G, Dimension 0.25G, and Snap-
shot 2.5TG -- were safe on Albo-marginata and Meta Peka hosta.
No significant injury or growth reduction was seen with either
plant when treated with these herbicides. However, autumn 
fern
and holly fern exhibited significant injury and suppressed growth
when treated with Dimension 0.25G or Snapshot 2.5TG. Of the
commonly used preemergence-applied herbicides, Rout 
3G, OH-
2 3G, and Ronstar 2G caused the most injury and growth 
inhibi-
tion.
These data show that potential exists for use of these 
newly
registered preemergence-applied herbicides on some 
sensitive
crops. However, users must be aware of current labeling and only
use pesticides on crops for which they are labeled.
METHOD
In March of 1991 and 1992, Hostafortunei Albo-marginata,
Hostafortunei Meta Peka, Dryopteris erythrosora (autumn 
fern),
and Cyrtomiumfalcatum Rochfordianum (holly fern), which are
all sensitive to the standard herbicides currently used, were potted
in three-quart (trade gallon) containers. A pinebark and peat moss
medium (3:1, by volume) amended with 14 pounds of Osmocote
17-7-12, six pounds of dolomitic limestone, two pounds of gyp-
sum, and 1.5 pounds of Micromax per cubic yard was used.
Treatments included ten herbicides and a unweeded check for
comparison (see tables). Treatments were applied on April 14,
1991, and April 17, 1992. All treatments were placed under 47%
shade cloth and irrigated as needed with overhead impact irriga-
tion.
RESULTS
With both hosta cultivars, Rout preemergence-applied herbi-
cide caused the greatest injury, while OH-2 and Ronstar also
caused significant damage (Table 1). By 60 days after treatment,
plants had grown past injury symptoms, and no injury was noted.
With the recently registered herbicides, no injury occurred to
either hosta cultivar at any time. Plants of both cultivars treated
with Rout generally had the least growth. Generally, there was no
growth suppression with any of the recently registered herbicides
to the hosta cultivars.
In both years, the greatest injury to both hardy fern species
resulted when Dimension was applied (Table 2). The remaining
treatments caused no significant injury to autumn fern. However,
holly fern exhibited injury symptoms with other treatments,
including Ronstar, OH-2, and Rout at 30 days after treatment, and
Snapshot 2.5TG at 60 days after treatment.
After Dimension, Snapshot 2.5TG generally suppressed
growth of both fern species the most in both years. In 1991, liners
were about one inch tall when treated, while in 1992 the liners
were about two inches tall when treated. Application of herbicides
to younger and smaller plants may explain why growth of the two
ferns was reduced more in 1991. Autumn fern growth was sup-
pressed by SWGC, Rout, OH-2, and Ronstar in 1991. But in 1992
no growth reduction occurred with any of these treatments,
perhaps relating back to the size of the liner at potting. Holly fern
treated with Ronstar and SWGC in 1991 had growth indices of
about seven inches; significantly lower when compared to the
check.
Lauderdale is a Graduate Research Assistant and Gilliam is Professor
of Horticulture; Olive is Superintendent of the Ornamental Horticulture
Substation.
Table 1. Effects of Preemergence-Applied Herbicides on Two Hosta Cultivars
Treatment Albo Marginata Meta Peka
Growth Index' Injury
2  
Growth Index
1  
Injury
2
1991 1992 1991 1992
in. in. in. in.
Devrinol
3  
.............
.. ... .. ......
............... 19.8 17.5 2.5 20.1 22.6 0.0
Pennant
3 .....
.................. 
.......... .... . ...
..... 20.5 18.2 0.0 19.6 16.7 0.0
Derby
3 
......................
.. ... ... . .. . . ....
..... 18.8 17.9 0.0 20.6 15.7 0.0
Dimension
4 
.........
......... . . . . . . . .....
......
. . . ..  
19.8 18.2 0.0 19.6 15.4 0.0
Snapshot
3  
...................... 
........ ... . . ....
..... 18.5 18.0 0.0 20.0 17.2 0.0
SW GC
3  ..........
...........
..... . . . . . ....
........ 18.6 16.5 0.0 18.2 16.6 0.0
Rout
5  . .........
................................
................ . . . . .
...... 13.4 16.7 37.5 16.8 16.3 32.5
OH-2
5  
..........................................
.........
.............. 16.0 18.0 23.8 17.1 16.4 22.5
Ronstar
s  ......
................................
......... ... . . ....
..... 17.8 18.1 25.0 18.1 18.1 17.5
Prodiamine
3 
.............
......... ..... . . . . . . . ....  
18.4 16.8 2.5 19.9 16.6 0.0
Unweeded ................................................ ..... 19.0 16.0 0.0 19.4 18.5 0.0
Table 2. Effects of Preemergence-Applied Herbicides on Two Hardy Ferns
Treatment Autumn fern Holly fern
Growth Index' Injury
2  
Growth Index
1  
Injury
2
1991 1992 30 DAT 60 DAT 1991 1992 30 DAT 60 DAT
in. in. in. in.
Devrinol
3 
...........
.. . . . . . . . . . .
... 19.8 13.7 0.0 0.0 16.9 19.6 3.8 0.0
Pennant
3 ... ... ... ... .
............... 19.8 16.4 0.0 0.0 22.9 19.1 0.0 0.0
Derby
3 
..............
. . . . . . . . . . . . . .
... 17.9 14.5 0.0 0.0 15.0 18.4 0.0 0.0
Dimension
4 
...........
. . . . . . . . . . .
... 1.3 1.0 0.0 40.0 0.0 5.4 15.0 67.5
Snapshot
3 
............
. . . . . . . . . . . . .
... 7.3 14.4 0.0 0.0 4.8 11.8 5.0 27.5
SWGC
3 
.............
.. . . . . . . . . . . .
... 10.0 14.0 0.0 0.0 7.1 16.1 0.0 0.0
Rout
5 
...............
.. . . . . . . . . . . . . .
... 12.2 14.0 0.0 3.8 12.1 19.0 13.8 0.0
OH-2
5 
................
............ . . 
11.8 13.8 0.0 0.0 14.2 18.8 18.8 0.0
Ronstar
5 
............
.. . . . . . . . . . . .
... 10.5 10.9 0.0 5.0 7.4 17.0 27.5 0.0
Prodiamine
3 
.........
. . . . . . . . . .
... 17.2 16.8 0.0 0.0 13.5 22.0 0.0 0.0
Unweeded ......................... 20.0 14.8 0.0 0.0 16.3 20.2 0.0 0.0
'Growth index = (height + width
1 
+ width
2
)/3. Width
1 
was at the widest point; width
2 
was perpendicular to width 
.
2Injury ratings: 0 = no injury, 100 = dead. Plants were rated 30 days after treatment (DAT) to derive the data in Table 1. Plants were rated 30 and 60 DAT to derive
the data in Table 2. Only the 1992 injury ratings are presented.
3
Four pounds of active ingredient per acre.
4
Two pounds of active ingredient per acre.
5
Three pounds of active ingredient 
per acre.
30
Transmission of Phytophthora parasitica in an Ebb and Flow 
Subirrigation System
Stephen S. Strong, C. Fred Deneke, Kira L. Bowen, Bridget K. Behe, and Gary 
J. Keever
Ebb and flow subirrigation is a closed production system that
recirculates a water/nutrient solution and collects its own runoff.
Water pumped from a storage tank floods the surface of a leak-
proof floor or bench, where the solution flows around and beneath
potted plants. Water is transported up through the growing media
by capillary action. After a predetermined time, water flow is
terminated and the remaining solution allowed to drain back to a
tank or collecting pond. The system conserves water and fertilizer,
decreases groundwater contamination, and reduces foliar disease.
However, ebb and flow may spread plant pathogens in the
recycled nutrient solution. Bacteria and fungi can move freely in
water and possibly cause large crop losses. Research was con-
ducted to determine the rate of transmission of the root rot
pathogen Phytophthoraparasitica from diseased to healthy plants
in an ebb and flow system.
Results from this study showed that root pathogens can be
spread up to 23 inches on recirculating subirrigation bench, and
approximately 36% of the plants exhibited severe root injury at
close spacing. Wider plant spacing may be an important factor in
reducing the severity of disease spread. This research was par-
tially supported by the Bedding Plants Foundation.
METHODS
Five-week-old seedlings of annual vinca(Catharanthus roseus
Peppermint Cooler) were transplanted into three-inch pots con-
taining Fafard No. 2 peat:perlite medium. The Canadian sphag-
num peat:perlite medium used in this study was steam pasteurized
to allow for more accurate detection of Phytophthora by eliminat-
ing existing pathogens. However, pasteurization of peat is not
recommended in commercial production because beneficial mi-
croorganisms are destroyed that may suppress root diseases caused
by Phytophthora and Pythium.
Six rows of seven plants were placed on 4x6-foot ebb and
flow benches (Photo 17, Page 20). The first row placed closest to
the drain end of each bench was inoculated with Phytophthora
parasitica. These treated plants served as an inoculum source for
the rows of untreated plants. Plants were spaced at a distance of 7/
16 inches between pots on two benches (Group 1), and a distance
of 1 5/8 inches between pots on two other benches (Group 2).
Plants were harvested from each of the untreated rows at two-
week intervals, and root samples were tested for evidence of
Phytophthora. The crop was grown for six weeks on the benches
and was fertilized at each irrigation with a solution of 100 parts per
million (ppm) nitrogen from Peters 20-10-20. Samples from the
irrigation tanks were tested for the presence of pathogen spores at
two-week intervals.
RESULTS
Monitoring of pathogen movement showed spread from the
inoculated row to the fifth untreated row of plants on all benches
by the sixth week. Phytophthora had spread across the benches 
a
total distance of 17 inches in Group 1 and 23 inches in Group 2.
However, only 13% of infected Group 2 plants exhibited severe
root injury (up to 25% root system injured), compared to 36% of
those infected at the closer spacing. See the table for an analysis
of the rate of Phytophthora infection. All the inoculated 
plants
from both groups died by week six, and the pathogen was recov-
ered from all samples. Sampling of the irrigation solution revealed
the presence of the pathogen in one of the Group 1 tanks at week
six.
Sanitation of production areas and disinfection of equipment
reduce the chances of a disease outbreak, but other measures may
be necessary once a pathogen becomes established in an ebb and
flow system. Chemical pesticides are commonly applied in con-
ventional production systems. However, there are currently no
fungicides or pesticides registered for recirculation.
Movement of Phytophthora parasitica to Non-inoculated
Plants Spaced at Two Distances on Ebb and Flow Benches
Spacing Non-inoculated Plants Infected
Week 2 Week 4 Week 6
in. pct. pct. pct.
Group 1 ............... 7/16 6 23 60
Group 2 .............. 1 5/8 0 10 30
Strong is former Graduate Assistant, Deneke is former Assistant Professor,
Behe is Assistant Professors, and Keever is Professor of Horticulture;
Bowen is Associate Professor of Plant Pathology.
Chemical Control of Azalea Lace Bug
James C. Stephenson, Michael L. Williams, and John W. Olive
The azalea lace bug, Stephanitis pyrioides, is a common
economic pests in azaleas, one the primary nursery crops in south
Alabama. Until recently, the insect had not been difficult to
control.
This insect is often present year-round, but greatest abun-
dance occurs during the warmer months. Lace bugs are very
mobile and are commonly found on lower leaf surfaces. Injury
results from insect feeding that produces chlorotic spotting on the
upper leaf surface. Numerous cast skins and circular black fecal
spots usually are present on the lower leaf surface.
AAES tests indicated a number of labeled insecticides pro-
vide good azalea lace bug control when properly applied. Thor-
ough coverage of foliar sprays remain one of the most important
factors in controlling the azalea lace bug. The incorporation 
of
Orthene 15G at higher rates may also prove useful in the 
future.
METHODS
Test 1 evaluated foliar application of three relatively new
materials or formulations and four common ornamental-labeled
insecticides. Rhododendron x Treasure grown in three-gallon
containers of an amended pine bark:peat moss medium were
treated with a single foliar spray to all leaf surfaces until run-off.
No spray adjuvants were included. Treatments were replicated
and plants placed under 47% shade cloth. Evaluation was con-
ducted seven days after treatment using a modified beat-sheet
. ~ 1 1 1 ..1 1 1_ __._ ~C1___~ ___-I-~-- ~1-
method to count live adult lace bugs.
Test 2 evaluated the efficacy of a pre-plant incorporation of
Orthene 15G as a preventative treatment. Rhododendron x Christ-
mas Cheer liners were potted in trade gallon containers of an
amended pine bark:peat moss (3:1) medium. Orthene 15G was
pre-plant incorporated at several different rates into the media. A
foliar-applied treatment of Orthene 75S was included as a stan-
dard for comparison. Treatments were replicated and plants placed
in close proximity to azaleas heavily infested with lace bugs.
RESULTS
In Test 1, good control was observed with all materials tested
when compared to the untreated check (Table 1). Treatments
included two formulations of Talstar, Dycarb 76W, Mavrik 2F,
Margosan O, Orthene 75S, and Diazinon AG-500.
In Test 2, lace bug feeding damage was observed within 36
hours after treatment on most plants. At the first evaluation seven
days after treatment, little difference in lace bug numbers was
observed. However considerably less feeding damage was ob-
served with the single foliar application of Orthene 75S (Table 2).
At 21 days after treatment, the two highest rates of Orthene 15G
and the Orthene 75S foliar spray provided control (Table 2). The
plants receiving the foliar spray had the least amount of feeding
damage. At 21 days after treatment, similar results were observed
(data not presented). In the final count, 35 days after treatment,
only the standard foliar-applied Orthene 75S provided some
control (data not presented). No phytotoxicity was observed in
either test.
Table 1. Chemical Control of Azalea
Lace Bug Seven Days After Treatment
Treatment
1  
Application rate
2  
Live bugs
3
Talstar 10W P ............................. ............. 12.8 3.5
Talstar 80 g/F ...... ............. 15.3 0.5
Dycarb 76W........................16 0.3
Mavrik Aquaflow 2F................. .................. 5 2.3
M orgasan O 0.3% ......................... ............. 80 3.0
Orthene 75S ...................... .............. 10.6 0.5
Diazinon AG-500 ......................... ............. 16 1.8
C ontrol ......................................................... .. 0 43.3
Table 2. Preventative Treatment for Azalea Lace Bug
Treatment' Rate
4  
Live bugs
3
7 DAT
5  
21 DAT
Orthene 15 G .................... 0.11 2.5 12.3
Orthene 15 G .................... 0.23 3.3 12.3
Orthene 15 G .................... 0.45 4.0 5.3
Orthene 15 G .................... 0.66 3.0 3.3
Orthene 75 S..........................1 2.3 0.8
Control................ 0 5.5 17.5
1
Treatments applied July 17, 1991.
2
Talstar 80 g/1F, Mavrik Aquaflow 2F, and Morgason 
O 0.3% are measured in
fluid ounces per 100 gallons of water; others are measured in ounces per 100
gallons.
3
Mean number 
of live lace 
bugs per container.
4
Orthene 75 S is a foliar spray and was applied at the rate of one pound per 100
gallons of water. All other treatments were applied on the basis of pounds per
cubic yard.
5
Days after treatment 
(DAT).
Stephenson is Associate Superintendent and Olive is Superintendent of the
Ornamental Horticulture Substation; Williams is Associate Professor of Entomology.
Fungicidal Control of Southern Blight on Aucuba
Austin K. Hagan and John W. Olive
Southern blight, which is caused by the soil fungus Sclero-
tium rolfsii, is a destructive disease of aucuba, ajuga, and other
woody ornamentals. It has usually been seen in field and land-
scape beds but considerable damage has been reported on con-
tainer-grown aucuba. Terraclor fungicide has been used to control
southern blight, but there are some questions concerning its
effectiveness on ornamentals. Also, several experimental fungi-
cides active against the southern blight fungus have been identi-
fied.
An AAES study was conducted to evaluate several of these
new fungicides for the control of southern stem rot on aucuba.
Two of the new products, Prostar and ASC66825, completely
protected aucuba from southern blight.
METHODS
Aucuba cv. Golddust liners were potted in one-gallon con-
tainers in a pine bark-peat moss media 3:1 (by volume) amended
with 14 pounds of Osmocote (17-7-12), six pounds of dolomitic
limestone, two pounds of gypsum, and 1.5 pounds of Micromax
per cubic yard of medium. Plants were located in partial shade and
watered daily with overhead sprinklers. Fungicides were applied
on Sept. 2 as a heavy spray/drench using a CO2-pressurized
backpack sprayer. All treatments, with the exception of the
noninoculated control, were inoculated with sclerotia of S. rolfsii,
and then held for several days in a hot, humid enclosed area. Plant
mortality was determined on Sept. 30.
RESULTS
All plants treated with Prostar and ASC66825 appeared
healthy. Folicur and Terraclor gave some protection from south-
ern blight but neither fungicide proved as effective as Prostar and
ASC66825. Plant mortality of the Terraguard and Curalan-treated
aucuba was similar that of the inoculated controls. None of the
noninoculated controls died from southern blight.
Effects on Plant Mortality of Fungicidal Control
Fungicide
1  
Plant mortality
Folicur 3.6F (8 f . oz.) ................................................................. 20
Prostar 50W (2 lb.) ............................................................... 0
ASC66825 50O F (32 fl. oz.) ..................................................... 0
Terraguard 50W (1 lb.).............................................................60
Terraclor 75W (1.25 lb.) .......................................................... 30
Curalan 50DF (8 oz.) ............................................... 70
Inoculated control ..................................................................... 80
Noninoculated control .......................................... ..................... 0
1
Application amount is given in parenthesis; rate is per 100 gallons of water.
Hagan is Professor of Plant Pathology and Olive is Superintendent of
the Ornamental Horticulture Substation.
All __1-~_I^ I---
32
Use of Selected Pesticides And Pesticide Combinations Against
Sweetpotato Whitefly on Container-Grown Ornamentals
Michael L. Williams and James C. Stephenson
Southern growers are desperate for new ways to control the
sweetpotato whitefly, Bemisia tabaci, the most troublesome and
difficult to manage of the whiteflies. Its potential for damaging
greenhouse-grown ornamental plants in Alabama is great because
of its amazing ability to tolerate pesticides, adapt to new host
plants, and reproduce rapidly.
Whiteflies, a common ornamental plant pest, cause damage
by sucking out plant juices and spreading diseases. Their nymphs
secrete honeydew, a growth medium for black sooty mold which
detracts from a plant's appearance and can interfere with photo-
synthesis. There are several species of whiteflies, but the
sweetpotato whitefly causes the most problems with indoor plants.
Sweetpotato whitefly resistance is broadbased, spanning at
least four classes of insecticides -- organochlorines, organophos-
phates, carbamates, and pyrethroids. Resistance in some popula-
tions of sweetpotato whitefly has been documented at the 54-fold
level. Some growers have turned to unlabeled products and
application methods in an effort to control the pest. In the interior
environment, the arsenal of pesticides available for use against
sweetpotato whitefly is limited. Because of human exposure
problems, highly toxic and long-lasting materials cannot be used
inside. For these reasons, AAES researchers are evaluating both
traditional and new materials for use against this pest in green-
houses and shadehouses.
Several pesticide combinations, soap, and oil sprays evalu-
ated in these tests provided good to excellent control and offer
additional materials to use in rotation with other pesticides to help
control and manage pesticide resistance in sweetpotato whitefly
populations.
METHODS
In 1991 nine pesticides and/or pesticide combinations were
evaluated for control of sweetpotato whitefly on container-grown
Chinese hibiscus, Hibiscus rosa-sinensis L., growing in the green-
house. Test materials were applied on Aug. 19 and 25, to 40 plants,
potted in three-gallon containers, that were heavily infested with
whiteflies. The foliar sprays were applied to run-off using hand
held compressed air sprayers. Care was taken to thoroughly cover
undersides of leaves. Granular materials were sprinkled on the
soil surface and watered in. Efficiency of materials tested was
evaluated seven and 14 days post-treatment.
In 1992, additional tests were conducted against sweetpotato
whitefly infesting container grown althea, Hibiscus syriacus L.
Test materials were applied on Sept. 2 and 9 to two-foot-tall plants
growing in one-gallon containers and heavily infested with
sweetpotato whitefly. Efficacy of the materials tested was evalu-
ated seven and 14 days post-treatment.
RESULTS
Best results in 1991 were obtained with combinations of
Tame 2.4 EC + Orthene 75 S and Orthene 75 S + Sunspray
Ultrafine Spray Oil. Both combinations provided 100% control of
sweetpotato whitefly infesting hibiscus after two applications
applied at a seven-day interval (Table 1). No plant damage, or
phytotoxicity, was observed.
Only Sunspray Ultrafine Spray Oil and pesticides used in
combination with Sunspray Ultrafine Spray Oil provided control
significantly better than the untreated control plants in the 1992
test. The Tame + Orthene combination that was so effective in the
1991 test was ineffective in the 1992 test. The only explanation for
its failure in 1992 is that the population of whiteflies tested against
in 1992 came from a greenhouse where previous attempts to
control them had failed, suggesting that pesticide resistance in the
test whitefly population may have been the reason for the lack of
control.
Table 1. Control of Sweetpotato Whitefly on Hibiscus, 1991
Treatment
1,2  
Mean pct. mortality
3
7DAT
4  
14DAT
Tame 2.4 EC
0.20 lb ................................ 31 42
Orthene 75 S
0.25 lb .......................... 29 47
Tame 2.4 EC+Orthene 75 S
0.20 lb.+0.25 lb. ....................... ........... 80 100
Orthene 15G
1.5 g ........................................................ 44 76
Orthene 75 S+Sunspray Oil
0.25 lb.+2 gal. ....................... 72 100
Talstar 10W
0.20 lb .............................. 44 55
Talstar 80F
0.20 lb. ............................. 38 64
Attack Soap
4 gal. .................................. 68 76
Avid 0.15 EC
8 oz. ....................... ................ 39 84
Control
0 ...................... ....... ....... ...................22 12
Table 2. Sweetpotato Whitefly Control on Althea, 1992
Treatment
1 ,2  
Mean pct. mortality
3
7 DAT 14 DAT
Tame 2.4EC+ Orthene 75s
0.2 lb.+0.25 lb ...... ....................... 13.50 11.75
Tame 2.4EC
0.2 lb ............................................... 11.25 17.50
Tame 2.4EC
0.3 lb........................ ........................ 9.25 14.50
Orthene 75s
0.25 lb ............................................... 5.00 8.75
Sunspray 6E
2.0 gal................................................90.00 98.25
Tame 2.4EC+ Sunspray 6E
0.2 lb.+2.0 gal..........................95.25 98.00
Talstar 80F
2.0 lb..................................................... 6.50 8.25
Orthene 75s+ Sunspray 6E
0.25 lb.+2.0 gal................................... 86.75 97.25
Dibeta ABG-6320
0.225 gal..................... 8.25 8.25
0........................................ 5.50 11.00
2
These rates are 
the amount of 
insecticide added 
to 100 gallons 
of water, except
for Orthene 15 G, which was applied at the rate of 1.5 grams per three-gallon pot.
3
Mortality determined Aug. 25 and Sept. 2, 1991.
4
Days after treatment (DAT).
Williams is Associate Professor of Entomology and Stephenson is
Associate Superintendent of the Ornamental Horticulture Substation.
1 r I i r i~V L3ID
33
Chemical Control of Two-spotted Spider Mite on Golden Euonymus
William H. Reynolds, James C. Stephenson, and Michael L. Williams
The two-spotted spider mite is a widespread pest species of
many ornamentals and is frequently encountered in landscapes,
interiorscapes, greenhouses, and nursery operations. Mild spider
mite infestations are characterized by a yellow or white stippling
of leaves. Chlorosis and leaf death accom-
panied with fine webbing both under the
leaves and at the leaf bases indicate heavy
mite infestations.
Adult spider 
mites are small 
(less than 
Treatment'
2
1/50 inch), yellow to green in 
color, and
have two dark spots on the body. The 
aver- Tame 2.4 EC+ Orthene
age female spider mite produces 100 to 200 Tame 
2.4 EC (0.20 lb.
eggs with oviposition occurring on all plant 
Tame 2.4 EC (0.30 lb.
surfaces. Under favorable 
conditions, the Orthene 
75S (0.25 lb.)
Sunspray 6E (2.0 gal.)
entire life cycle requires little more than a Attack Soap (4.0 gal.)
week (eight to 12 days). High humidity and DiBeta 
5 AS (2.0 pt.).
poor air circulation provide 
favorable con- DiBeta 
5 AS (4.0 pt.)
ditions for spider mite outbreaks. Control (0) .................
Nine pesticides and/or pesticide com- Treatment applied Se
binations were evaluated for control of two- 
2
Amount of pesticide p
spotted spider mites within a shadehouse 
3
Samples consisted of f
facility in Mobile 
in September 1992. 
Of from four plants. 
Saml
after treatment.
the nine treatments, Attack Soap at four gallons per 100 gallons of
water and DiBeta 5 AS at two and four pints per 100 gallons
provided best control. Plant damage was not observed in any of the
treatments.
METHODS
Heavily infested golden euonymus
shrubs, Euonymusjaponica Aureomarginata,
in trade gallon pots were selected for treat-
ment. Test materials were applied to upper
and lower leaf surfaces with hand-held com-
pressed air sprayers on Sept. 9, 1992. Seven
days after treatment, terminal shoots bear-
ing four leaves were removed from each
plant. Terminals were brushed with a mite-
brushing machine onto a counting disc and
the number of living mites counted. Due to
mite damage and overall decline of the plants,
the test was terminated after one week.
Reynolds is Graduate Research Assistant
and Williams is Associate Professor of Entomol-
ogy; Stephenson is Associate Superintendent of
the Ornamental Horticulture Substation.
Chemical Control of Spot Anthracnose of Dogwood
Austin K. Hagan, John W. Olive, and Leonard C. Parrott
Spot anthracnose, caused by the fungus Elsinoe corni, is a
common foliar disease of flowering dogwood. On leaves, flower
bracts, berries, and young stems, numerous small circular spots
with reddish purple margins and a tan or grey center may be seen.
Severe infections can cause distorted and tattered leaves.
Several non-registered compounds and labeled fungicides
were evaluated for control of this disease on flowering dogwood.
Of the fungicides screened, only Daconil 2787 4.17F and Daconil
2787 WDG are currently registered for use on dogwoods, but not
specifically for the control of spot anthracnose. Based on the
successful control of this disease in these trials, spot anthracnose
could be included on the Daconil 2787's 1994 label.
METHODS
White seedling dogwoods, infested with E. corni, were pot-
ted in three-gallon containers in February 1991 and 1992. The
potting medium was milled pine bark and peat moss (3:1, by
volume) amended with six pounds limestone, two pounds gyp-
sum, 1.5 pounds Micromax, and 14 pounds Osmocote 17-7-12 per
cubic yard. Fungicides were applied at seven-day intervals from
May 28 to July 22, 1991, and 14-day intervals from April 4 to May
22, 1992. Spray treatments were applied to run-off. Disease
severity was determined on June 30, 1991 and May 23, 1992.
RESULTS
In 1991 and 1992, all fungicide treatments were effective in
reducing the severity of spot anthracnose on dogwood foliage, and
similar control was observed with all fungicides evaluated. Re-
sults indicate that a 14-day spray interval may be sufficient to
control this disease with the fungicides evaluated in 1992.
Hagan is Professor of Plant Pathology; Olive is Superintendent of
Ornamental Horticulture Substation; Parrott is Research Technician IV.
Table 1. 1991 Evaluation of Fungicidal Treatments for Control of Spot
Anthracnose of Dogwood (Seven-Day Spray Schedule)
Fungicide' Disease severity
2
D aconil 2787 4.17 F (2 pt.)...................... ................................... 1.5
D aconil 2787 4.17 F (4 pt.) ....................... ................................... 1.3
Daconil 2787 W DG (1.25 lb.)................................... .................. 1.4
D aconil2787 W D G (2.5 lb.)........................................................... 1.2
A SC 66791 (32 oz.) .................................................. ...................... 1.3
A SC 66791 (64 oz.) ............................................ ............................ 1.6
Rally 40W 
3  
(5 oz.) ........................................................................... 1.6
B enlate 50W 
4  
(8 oz.) .............................................. ...................... 1.4
Folicur 3.6F (4.5 f. oz.)...................... .......... ... ................... 1.6
N on-sprayed control (0) ....................................... .............................. 2.8
Table 2. 1992 Evaluation of Fungicidal Treatments for Control of Spot
Anthracnose of Dogwood (14-Day Spray Schedule)
Fungicide' 
Disease severity
5
Daconil 2787 4.17 F (2 pt.).......................... ............................... 2.3
D aconil 2787 4.17 F (4 pt.)................................................................2.0
Daconil 2787 WDG (1.25 lb.)...........................1.5
Daconil 2787 W DG (2.5 lb.)........................ .... ................... 2.0
R ally 40W (35 oz.)......... ........................................ ...................... 1.7
Folicur 3.6F (4.5 fl. oz.) ........................................ ............. .......... 1.3
N on-sprayed control (0) ......................................... ............................ 5.2
'Rate is per 100 gallons of water.
2
Disease severity scale used in 1991: 1 = 0%, 2 = 25%, 3 = 50%, 4 = 75%, and
5 = 100% of new foliage affected.
3
Federal registration of Rally 40W on some ornamentals is expected in 1993, but
it may not be cleared for use on dogwoods.
4
Benlate's registrations on all ornamentals were withdrawn by the manufacturer.
5
Disease severity scale used in 1992: 1 = 0, 2 = 0-3%, 3 = 3-6%, 4 = 6-12%, 5 =
12-25%, 6 = 25-50%, 7 = 50-75%, 8 = 75-88%, 9 = 88-94%, 10 = 94-97%, 11 =
97-100%, and 12 = 100% of new growth affected.
spotted Spider Mite
Mites
per sample
3
................................ 2 1.5 0
) ............................. 25.75
) ............................. 50 .25
............................... 10 .00
.................................. 7 .00
................................... 4.50
................................. 32 .75
............... .............. 23.00
tember 9, 1992
er 100 gallons of water.
our terminal leaves per plant
ples were taken seven days
VbbU I~LC~IIV~ IYVUI ,VII VVV_~LIIL~b V11~C~IYLC)IIC ( nrtlPnP 7~C /~ 3C Ih \1 3/; 7~
~ ~'''"" -^'~'J ^ -b'"'-''-r ^ v- -ru - ,-- ,,~ -- -- n-. 7 -- --- ---- -
34
Dogwood Anthracnose on Dogwood in Alabama: Its Distribution and Severity
Austin K. Hagan and Jackie M. Mullen
Dogwood anthracnose poses a significant threat to the health
of flowering dogwood in Alabama's forests. The destructive
disease has recently been found on flowering dogwood (Cornus
florida) in forested and landscape sites in Appalachian Mountains
and nearby uplands in the Southeast. In Alabama, this disease has
been found in four northern counties and in Lee County, but the
distribution and extent of damage to dogwoods in the state are not
known.
Stands of native flowering dogwood in state parks and na-
tional forests in north Alabama were checked in the late spring,
1991 and 1992, to determine
dogwood anthracnose. Trees
found along one or more sites
at each location were exam-
ined for symptoms of the dis-
ease.
Death of understory trees
was seen at one location and
considerable foliage damage
was seen at several others
across extreme northeast Ala-
bama. Continued intensifica-
tion of this disease, particu-
larly on seedling and young
trees, will eventually result in
elimination of dogwood from
some Alabama forests. The
appearance of this disease at
lower elevations shows that
dogwood anthracnose may
also spread over a much wider
area of the state than origi-
nally thought. Problems with
this disease also are likely in
the next few years on dog-
wood growing on shaded ar-
eas in home and commercial
landscapes across much of
north Alabama.
Controls for dogwood an-
thracnose include planting
healthy trees, avoiding dog-
woods transplanted from the
forest, pruning surrounding
trees to improve sunlight pen-
etration and air circulation,
maintaining good soil fertil-
ity, light pruning to open the
tree canopy and remove dead
wood, establishing new trees
on sites open to sunlight, sur-
face watering weekly during
drought, mulching trees, and
fungicide sprays. No flower-
ing dogwoods resistant to this
disease have been found.
the distribution and severity of
METHODS
Disease occurrence and severity at each site were recorded. In
1992, disease severity was assessed on each tree by a modified
Miekle-Langdon scale (see table footnote for description). Dis-
ease severity was not determined using this scale in 1991. Leaves
from trees with typical disease symptoms were examined for the
presence of the causal fungus, Discula destructiva.
RESULTS
In 1991, typical leaf spot and blight were seen on nearly all
dogwoods examined in Monte Sano State Park in Madison County
and Desoto State Park in DeKalb County. Twig dieback and tree
Dogwood Anthracnose in Alabama, 1992
Disease severity
I I Not surveyed
E Healthy
J I Light
iModerate
Severe
* Sites Surveyed
S.P. State Park
N.F. National Forest
~ririnc- m r rlll~l~c- s;rrlrl Iri I.r.~-~ I riiiriiv riit Irir. r .,
I I~ Lk
35
death, which are associated with severe anthracnose injury, were
not seen in either park, but few healthy trees were found. Symp-
toms were lighter on the taller dogwoods than on the smaller
understory trees. Elevation of sites surveyed in both parks was
1,600 to 1,700 feet.
Some leaf spotting was seen on a few scattered trees near the
lodge in Lake Guntersville State Park in Marshall County and
along the north rim of the Little River Canyon in DeKalb County
(elevation 1,000 feet). No dogwood anthracnose was found on
trees along several lake-front trails in Lake Guntersville State
Park. One dogwood with typical leaf spot symptoms was found in
Buck's Pocket State Park in DeKalb County and in the Talladega
National Forest in Calhoun County. No diseased trees were found
at two other locations in the Talladega National Forest in Cleburne
County, or several sites in Cheaha State Park in Clay County.
Also, dogwood on several sites in Wheeler State Park in Lauder-
dale County, Wind River State Park in Tallapoosa County, and
Oak Mountain State Park in Shelby County were healthy.
Favorable weather conditions in summer 1991 resulted in an
increase in the range and severity of dogwood anthracnose in 1992
(see table). Some shoot dieback along with the typical leaf spot
and blight was seen on all dogwoods examined in Monte Sano and
Desoto state parks. On a few trees, death of the lateral branches
was followed by the appearance of numerous water sprouts along
the main trunk. Tall dogwoods in direct sunlight suffered less
damage than the smaller, shaded understory trees.
Serious leaf blight and limb dieback occurred on dogwoods
along the north rim of the Little River Canyon and Coleman Lake
in Talladega National Forests in Cleburne County. Spread of the
disease to previously healthy dogwood stands was seen in Lake
Guntersville, Buck's Pocket, and Brymer Mountain and Horseblock
Mountain in Talladega National Forest in extreme southwest
Cleburne County. Dogwood anthracnose also was identified at
one site in Bankhead National Forest between Lawrence and
Winston counties. At several of these locations, diseased dog-
wood were found at elevations down to 600 feet. Also, one
symptomatic dogwood was found in Birmingham in Jefferson
County near Legion Field.
Trees at two sites south and west of Cheaha in the Talladega
National Forest in Clay County were healthy. The same was true
with all trees checked in Wind River, Oak Mountain, Wheeler
state parks and three sites in the Bankhead (Sipsey Wilderness) in
Winston and Lawrence counties.
Other foliar diseases of dogwood identified during the course
of this survey were spot anthracnose and botrytis blight. Of the
two diseases, spot anthracnose, which was found on dogwood in
partial to full sun, was the most common. The most extensive
outbreak of this disease was found on dogwood growing along the
rim of the Little River Canyon in Desoto State Park. Botrytis
blight, a disease that exhibits symptoms similar to dogwood
anthracnose, was rare.
Hagan is Associate Professor and Mullen is Plant Pathologist of Plant
Pathology.
Distribution and Severity of Dogwood Anthracnose
in Alabama on Flowering Dogwood in 1992
State Park or County Incidence Disease
National Forest rating
pct.
Rickwood Caverns ..................................... Blount 0 5.00
Talladega ....................................................... Clay 0.8 4.99
Talladega ............................................ Cleburne 40.1 4.40
D esoto ....................................................D eK alb 91.5 3.20
Buck's Pocket ........................................... DeKalb 37.2 4.50
Little River Canyon ................................. Dekalb 88.5 3.70
Bankhead ...................... ...................... Lawrence 0.9 4.95
W heeler ............................................. Lauderdale 0 5.00
Monte Sano ............................................. Madison 100.0 2.10
Lake Guntersville ................................... Marshall 12.1 4.74
Oak Mountain ............................................ Shelby 0 5.00
Wind River .......................................... Tallapoosa 0 5.00
Bankhead ....................... ....................... W inston 0 5.00
1
Disease severity was evaluated on each tree using a modified
Mielke-Langdon scale: 0 = dead tree; 1 = 75-100% leaves diseased with numerous
water sprouts; 2 = 50-75% leaves diseased with extensive twig dieback; 3 = 25-50%
leaves diseased with some twig dieback; 4= 1-25% of leaves diseased; and 5 = healthy
tree.
C~LI_ 7~-~-1_ ---- rc,,,,~,. T,,: ~,,,,
36
ENVIRONMENTAL PROTECTION
Nontarget Herbicide Losses from Application of Granular Ronstar 
to Container Nurseries
Charles H. Gilliam, Donna C. Fare, and Alan Beasley
Weed control is essential in container production, but in-
creasing concerns about water quality dictate that herbicide use
must be environmentally safe. Three main concerns regarding
herbicides in nursery runoff water are the location of container
nurseries in relation to surface water, potential plant injury from
recycled runoff water, and possible ground water contamination.
Granular herbicides are normally used to control weeds in
container nurseries. These herbicides are usually broadcast using
a cyclone-type spreader with up to five applications a year. When
applied to round nursery containers, 20% or more of the herbicide
falls directly to the ground between the containers. Previous
studies indicated that little leaching of chemicals occurs from
potting media when normal rates are used. These results suggest
that the greatest potential for water contamination is from the
grains of herbicide that fall to the ground.
A study was conducted to determine how these nontarget
losses are influenced by container spacing and plant species. It
revealed that nontarget granular herbicide loss from broadcast
application ranges from 23-30% when three-quart pots are spaced
adjacent to one another. Increasing plant spacing progressively
increases nontarget loss. From a practical standpoint, herbicide
applications should be made before spacing of containers if
possible. Furthermore, this work points out the need to develop
more refined granular herbicide application techniques to reduce
nontarget loss.
METHOD
A rectangular frame (7.5x4.2 feet) was constructed and
covered with a plastic sheet to allow recovery of the applied
herbicide. Ronstar 2G was applied at the manufacturer's sug-
gested rate of 200 pounds per acre. A hand-held shaker can was
used to apply the herbicide to empty three-quart containers. Three
spacings evaluated were container-to-container, and pots spaced
on eight- and 12-inch centers (1.5 and five inches between
containers, respectively). Each pot was lined with a plastic bag to
collect the herbicide going into the container. Herbicide falling
inside the containers was pooled and weighed, and herbicide
falling on the plastic sheet under the containers was weighed.
The test was repeated with containers of Trouper azalea
(Rhododendron x Trouper), representing a dense canopy plant,
and Crimson Pygmy barberry (Berberis thunbergii Crimson
Pygmy), representing an open canopy plant. Trouper azaleas
averaged 16.4 inches in height and 15.5 inches in width. Barberry
plants averaged 9.7 inches in height and 14.9 inches in width.
These container-grown plants were placed in a plastic bag to cover
the outside of the container and prevent container media from
falling onto the plastic sheet. Container size and spacing were
similar to the empty container test.
RESULTS
Canopy density appeared to have little influence on nontarget
herbicide loss. When spaced container-to-container, the nontarget
losses were 23%, 30%, and 27% for the empty pots, azalea-
planted pots, and barberry-planted pots, respectively. See the
table for other results.
Nontarget Loss of Ronstar 2G Herbicide with Broadcast Applications
as Affected by Pot Spacing and Plant Canopy
Container Spacing Pct. herbicide loss
Em pty ......................................... pot to pot 23
................................................ 8 in . 5 1
.............................................. 12 in . 80
A zalea .......................................... pot to pot 30
.......................................... ....8 in . 5 5
Barberry...................pot to pot 27
..................................... ....... 8 in . 54
............................................. 12 in . 80
Gilliam is Professor, Fare is former Senior Research Associate, and
Beasley is former student of Horticulture.
Monitoring Irrigation at Container Nurseries
Donna C. Fare, Charles H. Gilliam, and Gary J. Keever
Water use and runoff in container nurseries are major con-
cems to U.S. nursery operators. Improving water management is
the first strategic step in improving water quality and reducing
water usage and surface runoff from container nurseries.
Overhead irrigation is the primary irrigation method in South-
east container nurseries. Growers generally irrigate one hour a day
during the growing season, assuming an application of one inch of
water per hour. Overhead irrigation may apply 40,000 gallons per
acre daily, with losses of 16,000 to 36,000 gallons through
evaporation and runoff. In Alabama, total water used for irrigation
was reported at 77,000 acre-feet per year; the container nursery
industry uses up to 50,000 of that amount.
As a baseline, improving water management practices re-
quires an understanding of current irrigation procedures em-
ployed in container nurseries. A two-year survey was conducted
to determine irrigation distribution at Alabama container nurser-
37
ies. The survey reflects current production irrigation application
volumes in the state and is probably indicative of the South. The
amount of irrigation applied varied with each nursery sampled, but
averaged 0.6 inch per hour, or about 40% less than most nursery
operators assumed was being applied. Despite differences in
irrigation output, plants grown in the six nurseries surveyed were
of consistently uniform marketable quality.
Based on this survey, potential ways for improving irrigation
delivery include careful monitoring of output throughout the year
with adjustments to ensure uniform delivery, especially when
using overwintering structures. Most of the irrigation systems
were not checked for proper irrigation output or distribution, but
the growers assumed the system to deliver one inch of water per
hour.
The survey also emphasizes the need for uniform initial
design. Poor water distribution could have been improved with a
properly designed irrigation system. Output and distribution of
water from overhead systems are dependent upon many variables,
including wind, operating pressure, pipe size and spacing, nozzle
size and type, and plant size and spacing. These variables must be
considered in designing an irrigation system.
METHODS
Six container nurseries were monitored in 1989 and 1990 to
determine the amount and distribution of irrigation water applied
to container-grown nursery crops using overhead impact nozzles.
Irrigation systems were designed by the nursery operators or by
professional irrigation specialists. Growers at these nurseries
typically watered for about one hour. Four of the nurseries sur-
veyed (1-4) were located in central or south Alabama. Production
in these nurseries consisted mostly of trade- and full-gallon plants
potted in April or May, grown for one season, placed pot-to-pot
during the winter (November-March) and marketed during the
following spring. In the two north Alabama nurseries (5, 6) and
one nursery in south Alabama (3), plants were placed pot-to-pot in
polyethylene-covered overwintering houses during the winter.
All irrigation nozzles at these nurseries were located within the
overwintering structures. In the spring, the polyethylene was
removed and plants were spaced in the overwintering houses and
adjacent areas. These plants were marketable after a growth flush.
Taylor rain gauges were placed in plant containers to collect
irrigation water over a one-hour period. Fifteen gauges were
located in a grid system between or around irrigation risers within
a container block in each nursery. When plants were spaced in
Nurseries 3, 5, and 6, gauges were spaced further apart. Gauges
were placed at the same locations at each sampling in Nurseries 1,
2, and 4. With all nurseries, similar grid patterns for gauge location
were used, even though each nursery had a different irrigation
system design, including varied riser heights, riser spacing, and
nozzle types (see table). Calm conditions generally prevailed
during sampling.
RESULTS
Results were similar for the two years of the survey, so only
data from 1990 are reported. Average irrigation volumes applied
5 to 1.3 inches in Nursery 6, a four-fold difference. Excluding
Nursery 6, the average irrigation collected over the remaining five
nurseries was 0.6 inch, or slightly more than half of the one inch
that most growers assumed they were applying in an hour. An
average of less than a half inch of water was applied at Nurseries
2, 4, and 5, while an average of 0.7 inch was applied in Nurseries
1 and 3. Variation in irrigation volume among the sampled
nurseries may relate to differences in nozzle type, delivery pres-
sure, riser height, and spacing, as shown in the table.
Irrigation distribution varied widely over sampling times
within some nurseries, while the irrigation volumes collected
from other nurseries were relatively consistent. In Nursery 1, 0.9
inch was collected in June, but only 0.4 inch was collected in
November. In Nursery 3, the average irrigation collected ranged
from 0.6 inch in May to 0.8 inch in November. In contrast, the
hourly irrigation averages for Nurseries 2 and 4, were between 0.3
and 0.4 inch for all of the sampling times. These data demonstrate
that uniform irrigation distribution can be achieved. Furthermore,
careful monitoring of the irrigation system is needed to ensure
efficient water use and to minimize potential water runoff.
Temporary covering of winter protection structures altered
irrigation volumes measured. Nursery 6 used polyethylene-cov-
ered overwintering structures that confined irrigation to a smaller
area and resulted in almost three times the irrigation applied in
March as in the other five months of sampling -- 2.7 inches versus
one inch. A similar situation occurred in Nursery 5 where irriga-
tion from the November sampling (overwintering structures were
covered) averaged 0.8 inch, while the other five sampling dates
averaged 0.4 inch.
Irrigation distribution varied widely in the overwintering
structures. For example, at Nursery 6 during March (covered
structure), irrigation ranged from 0.8 inch to 4.3 inches. During
the growing season when the polyethylene was removed and
plants were spaced (May-September), the irrigation distribution
range was less, ranging from 0.5 inch to 2.1 inches among the 15
gauges. Most of these systems were designed to accommodate the
expanded growing areas. In most parts of the U.S., overwintering
structures (hoop houses) are a critical component of nursery
production. These data indicate that poor irrigation distribution
and utilization may occur in covered houses if the system is
designed for irrigating adjacent areas.
Uneven water distribution within a block of plants occurred
in all nurseries on at least one sampling date. Variations in
irrigation volumes were not confined to overwintering structures,
but due to other unidentified factors. Within-block variations
were relatively low in Nurseries 2 and 4 during May through
September, but in August at Nursery 3, irrigation ranged from 0.5
inch to 2.6 inches.
Fare is former Senior Research Associate, Gilliam is Professor, and
Keever is Professor of Horticulture.
varied widely from nursery to nursery (see figures). For example,
the average irrigation collected during a one-hour period in nurs-
eries for the six sampling times ranged from 0.3 inch in Nursery
38
Characteristics of Irrigation Systems at Six Wholesale Container Nurseries in Alabama
Nurseries
1 2 3 4 5 6
Nozzle types' 
.. . . . . . . . . . . . . . . . ..
Rain Bird 40 Rain Bird 30 Rain Bird 25 NAAN 30 Rain Bird 30 Rain Bird 25
Rain Bird 35 Rain Bird 35 NAAN 35
Nelson 631 A
Operating pressure (psi) ............. 30-80 30-80 30-70 25-65 30-80 30-70
Riser spacing (ft.) .................. 40x40 48x48 102 40x4O 152 152
Riser height (ft.) ................................. 6 5 5 3 4 3
Container size (gal.) ....................... 23 1 1 33 23 1
Delivery pressure
at pump (psi)..................................... 75 60 60 45-65 80 8s5-90
'Manufacturer of Rain Bird nozzles is Rain Bird International, Inc., Glendora, Calif.; manufacturer of NAAN nozzles is NAAN Sprinklers and Irrigation Systems
Inc., Cerritos, Calif.; manufacturer of Nelson nozzles is R.L. Nelson, Inc., Orlando, Fla.
2
S ingle-row spacing inside overwintering 
structure.
'Trade size (three quarts).
Inches Inches
SMaximum
2 Average
L Minimum
0'
Nursery 1
Mar. May June Aug. Sept. Nov.
Inches
31
ii
Nursery 2
2F mAve ag
Mar. May June Aug. Sept. Nov.
Inches
4F 
Nursery 3
3
2
1
Nursery 4
ZJC -1C 6PEw
Mar. May June Aug.
Inches
3F
May June Aug.
Sept. Nov.
Nursery 5
Sept. Nov.
Inches
Mar. May June Aug. Sept. Nov.
Sampling time
Figure. These graphs show the minimum, average, and maximum irrigation volumes applied at six Alabama nurseries, March-November 199
Mar. May June Aug. Sept. Nov.
Sampling time
r ~~
Agricultural Waste Products as Composted Soil Conditioners
D. Joseph Eakes, Ronald L. Shumack, Charles H. Gilliam, and James O. Donald
Disposal of large quantities of waste products is one of the
largest problems facing agriculture today. These byproducts could
be turned into a valuable resource for the ornamental plant
industry as potting media and landscape soil amendments.
Peat moss was once considered the industry standard for
landscape soil amendments or conditioners, but its cost and
availability have made composted pine bark mixes more popular.
Some producers have expressed interest in mixing other composted
organic materials with pine bark, which could improve pine bark
soil amendments. It could also encourage conversion of agricul-
tural byproducts from potential pollutants to valuable resources.
An AAES study was conducted to evaluate cotton gin waste
and broiler litter as additives to composted pine bark soil amend-
ments or conditioners for herbaceous ornamentals in the land-
scape. It revealed three important facts about using these byproducts
with bark. First, composting foul-smelling material, such as
broiler litter, with cotton gin waste eliminated the odor. Second,
plant growth in compost-amended plots was equal to or better than
growth in peat moss-amended plots. Third, composted waste soil
conditioners did not provide adequate nutrition, so additional
fertilization is needed.
METHODS
Various combinations of cotton gin waste, broiler litter, and
pine bark were thoroughly mixed and placed into piles containing
about 12 cubic yards (Table 1). The piles were turned every three
weeks. The material composted rapidly. There was no detectable
broiler litter odor in any of the treatments where cotton gin waste
was incorporated into the compost.
Raised beds of pine bark-amended sandy loam soil were
treated with one of the compost treatments on Sept. 25 and planted
with Fizzy White kale and Orange Boy marigold. Treatments
were applied on a dry matter basis at the rate of 20 tons per acre
to 6.25x7-foot plots, and tilled in to a depth of two to four inches.
Half of the treatments received a commercial fertilizer application
at the recommended rate of 120 pounds of nitrogen (N) per acre
(Table 1). The two control treatments, peat moss-amended and
nonamended, also received the commercial fertilizer application.
RESULTS
Foliar color ratings were similar for Fizzy White kale when
comparing the composted treatments with the peat moss-amended
treatment where both received the recommended rate of fertilizer
(Table 2). All fertilizer-amended compost treatments provided
greater plant dry weight than peat moss, as shown in Table 2.
Kale composted treatments not receiving additional fertilizer
were smaller and off color compared to the treatments that did
receive the recommended fertilizer application. One component
of this test was to evaluate whether or not sufficient nutrients
would be available to the plants from the composted materials for
acceptable plant growth. These data indicate that even though
high nutrient levels are in the soil conditioners, they do not
provide adequate nutrition for immediate plant needs. Along with
the gin waste-broiler litter (1:1) treatment, about 800 pounds of N
per acre were applied. Perhaps the release rate of the organic N
was too slow for plant needs.
Orange Boy marigold was less responsive to the compost
treatments than Fizzy White kale. Color ratings and plant dry
weight were similar when comparing the composted treatments
plus fertilizer to the peat moss plus fertilizer treatment (Table 3).
The gin waste-broiler litter-pine bark (1:1:1) treatment produced
slightly larger plants than the peat moss plus fertilizer treatment
(7.3 versus 6.1 grams, respectively).
Table 1. Composition of Soil Conditioning Treatments Used
Components
-3  
Ratio Pct. N N lb./a.
GW-PB
4 
.......
.. ... .. . ....
.
....... . . . .
1:1 1.0 400
GW -BL-PB .......................................... 1:1:1 1.6 640
GW -BL-PB
4
................................ 1:1:4 1.3 520
GW -BL-PB .......................................... 1:2:7 1.2 480
GW-PB
4 
.......
.. ..... . . ... . . . . . . . . ...
... 1:4 0.8 320
GW-BL ................................... 1:1 2.0 800
Peat moss
4  . . . . . . . . . . . . . . . . . . .
None4None
4
.................. .......
...................... . . .
Table 2. Effects of Soil Conditioners on Growth of Fizzy White Kale
Components' Ratio Foliar color
5  
Dry weight
7
30 DAP
6  
60 DAP g
GW -PB
4  
....
..... . . .....
......... 1:1 3.8 4.8 32.1
GW-BL-PB ................. 1:1:1 2.3 2.9 4.3
GW-BL-PB
4 .. ... . .. .
......... 1:1:4 4.0 4.8 33.1
GW-BL-PB ................. 1:2:7 1.5 1.6 2.9
GW-PB
4 .. . . . . . . . . . . .  
1:4 3.8 4.8 28.3
GW-BL .................... 1:1 2.0 3.1 4.2
Peat moss
4
.......
. . . . . . . . . . . .
........ - 4.1 4.5 21.7
None
4  
........
........ . .. .. .
............. - 3.3 4.5 19.4
Table 3. Effect of Soil Conditioners on Growth of Orange Boy Marigold
Components' 
Ratio Foliar color
5  
Dry weight
7
g
G W -PB 
4 .....
.........................
................. .  
1:1 3.8 6.1
GW -BL-PB .......................................... 1:1:1 2.2 7.3
GW-BL-PB
4 
....................
.. . . . . . . . . . . . . . . . .
... 1:1:4 4.2 2.6
GW-BL-PB .......................................... 1:2:7 2.0 1.6
GW -PB 
4 ......
.........................
................ .  
1:4 3.5 6.5
GW-BL .................................. 1:1 2.0 1.8
Peat m oss
4  
............................
. . . . . . . . . . . . . . . . . . . . . .. 
- 4.4 6.1
None
4 . .....
.......... ......
. . . . . . . . . . . . . .................
- 3.2 4.5
GW = gin waste, BL = broiler litter, PB = pine bark.
2
All combination treatments were applied at 20 tons per acre on a dry matter
3
peat moss was added to plats at about a one-half to one inch depth.
4
These treatments received a commercial fertilizer application at the recom-
mended rate of 120 pounds of N per acre.
5
Foliar color rating scale: 1 = chlorotic, 3 = light green, and 5 = dark green.
6
DAP = days after planting.
7
One gram (g) is.035 ounce.
Eakes is Assistant Professor, Shumack is Department Head and Pro-
fessor, and Gilliam is Professor of Horticulture; Donald is Professor of
Agricultural Engineering.
~i~ll VI Lilt; LIC;itLIIIC;IIL3; I t;Clt;lV C;U ii C*VIIIIIIC;I~Lldl ICILLILL~L C1C-IIJIIC/CLLIVII
40
Consumers Favorably Evaluate a Growing Medium Containing Broiler Litter Compost
Bridget K. Behe, Lillie V. Purvis, Lisa M. Beckett, James O. Donald, and Charles H. Gilliam
In 1991, Alabama's poultry industry produced 3.76 billion
pounds of broiler chickens, but it was also left with the challenge
of disposing of millions of tons of broiler litter without harming
the environment. Composted litter can be used in potting media,
as a soil amendment, and as a fertilizer, but consumer perceptions
of its odor may limit marketability of the byproduct in horticul-
tural products.
An AAES study assessed consumer acceptance of a growing
medium amended with litter compost. It was conducted in con-
sumer homes to provide a realistic setting and compare a litter-
based product, AUmix, with two commercial alternatives, Baccto
and Hyponex. AUmix was comprised of broiler litter compost;
aged, amendment-grade pine bark; and horticultural-grade perlite
(by volume, 10:10:1).
Determining a perception of an unpleasant odor was the
study's primary concern. Few participants noticed any unpleasant
odor, and only a minimal amount was detected. Therefore, AUmix
odor perceptions should not limit its marketability. On other
factors -- water requirements, frond color, and plant health --
AUmix was rated higher than one of the commercial alternatives
and about on par with the other. These results indicate that a
growing medium amended with broiler litter compost could be
acceptable for use in consumer homes.
METHOD
On Oct. 17, 1990, commercially grown two-inch liners of
Dallas Jewel fern were transplanted into four-inch diameter plas-
tic containers with one of the media and grown for one week in a
fiberglass covered greenhouse. Between Oct. 24 and Nov. 1,
consumers randomly chose a set of three ferns that included an
instruction sheet, six color-coded forms for weekly evaluations,
and six postage-paid envelopes. Containers were labeled as either
A, B, or C, and media order was randomly varied in each fern set.
Average Consumer Ratings of Three Media Attributes
Care instructions were provided on commercially-produced tags.
Participants were told that the purpose of this study was to
evaluate a new potting mix. They were not told that one medium
contained broiler litter compost. (See Photo 18, Page 20.)
Consumers included 119 members of Lee County garden and
homemaker clubs. Participants ranged in age from 33-85, and
87% had completed some college or earned a college degree.
Average per capita income was $21,502, and the average house-
hold had 2.5 residents; 88% were female and 12% were male.
From Nov. 2 through Dec. 7, consumers evaluated each fern
on four attributes (water required, frond color, plant health, and
mix odor), comparing the plant being rated to the other two plants.
Ninety-four percent of the consumers completed the study. Con-
sumer ratings were averaged and compared.
RESULTS
Over the six-week evaluation, ferns in Hyponex required the
most water (see table). For weeks two through six, ferns in AUmix
required an amount of water intermediate to ferns in Hyponex and
Baccto. Ferns grown in Hyponex were perceived to be a lighter
green when compared to plants in AUmix and Baccto, with
similar mean color ratings. Ferns in Hyponex were perceived as
less healthy than fern plants in AUmix or Baccto, which received
similar mean health ratings. Consumers noticed minimal unpleas-
ant odor from Baccto and Hyponex, less than was noticed from the
AUmix (see table). No more than 13% of the participants rated
AUmix unpleasant odor a two or higher during the evaluation, and
it was judged to be only slightly more unpleasant.
Behe is Assistant Professor, Purvis is former Graduate Student, Beckett
is Research Associate, and Gilliam is Professor of Horticulture; Donald is
Professor of Agricultural Engineering.
for Three Media with Dallas Fern Over Six weeks of In-home Evaluations
Medium Water' Color
2  
Health
3  
Odor
4
B accto .......................................................... 3.3 3.7 3.7 1.1
H yponex ....................................................... 2.2 3.0 3.1 1.1
A U m ix .......................................................... 2.3 3.6 3.6 1.2
'Water required was rated from 1 = little water required to 5 = a great deal of water required.
2
Fern frond color was rated from 1 = light 
green to 5 = dark green.
3
Fern health was rated from 1 = fair health to 5 = excellent health.
4
Odor of media was from rated 1 = no unpleasant odor to 5 = strong unpleasant odor.
L;V113;U111~313; litllUVIIIIV C;IIV3;t; i~t 3;C;L VI LIIICC 1~1113 LllitL III~IUU~LC all

Alabama's Agricultural Experiment Station System
AUBURN UNIVERSITY
With an1 a"]-tCLt Iral
r-esear-chLl it In es erv
m-aJor soil aiea, ALI-
burn tinis ersitv servs 
thle needs (4 fi'eld
crop. livestock. [or-
eStr'\, Lland hor1ticutur1LIal
produIcerS InI each
region in Alabamia.
Every citizen of' the
state has a stake t1i
this reseat~ch program.,
since an\ ads, antage
from nes \ and more
economiical w5ays of
prodLicinu and hiand-
lineL l'al1 rm Prod Ittcs
directl\ bene I ts the
conISumIine1- pLblic.
Research L nit Identification
*Main Agricultural Experiment Station, Auburn.
SE. V. Smith Research Center, Shorter.
Tennessee Valley Substation. Belle Miria.
Sand Mounrtain Suhsraticn Crossvile
North Alabama Horticulture Substation, Cullman
Upper Coastal Plain Silbstation. Winfield
Forestry Unit, Fayette County.
Chilton Area Horticulture Substation, Clanton
Forestry Unit, Coosa County
Piedmont Substatior. Camp Hill
Foresty Unit. Autauga Courty.
Prattville Experiment Field. Prattville
11Black Belt Substation. Marion Junction.
12 The Tiirn inseed- ilen berry Place, Union Springs.
13 Lower Coastal Plain Substation, Camden
14, Forestry Unit, Barbour Counrty.
15. Monroeville Experiment Field, Monroeville.
16 Wiregrass Substation, Headland.
17 Brewton Experiment Field Brewton.
18B Oranmental Hurticultore Substation, Spring Hill.
19 Culf Coast Suostation. Fairnope