January 1983
Horticulture Series No. 29
Auburn University
Agricultural Experiment Station
Gale A. Buchanan, Dean and Director
Auburn University, Alabama

RESEARCH RESULTS FOR ORNAMENTAL HORTICULTURISTS
Horticultural Series No. 29
Alabama Agricultural Experiment Station
Gale A. Buchanan, Dean and Director
Auburn University January, 1983
Auburn University, Alabama Kenneth C. Sanderson,
Editor
CONTENTS
Page
November Through May Propagation of'Photinia x fraseri Tip
Cuttings with IBA and NAA. Fred B. Perry, Jr. .......... 1
Postemergence Control of Grass Weeds in Field Grown Ornamentals.
C, H. Gilliam, C. T. Pounders and T. Whitewell . . . . . . . 2
Fungicide Evaluation for Azalea Petal Blight Control 1981.
A. Hagan and C. Gilliam .... ............. . ........ 4
Fungicide Evaluation for Botrytis Petal Blight of Geranium
1981. A. Hagan, R. Shumack and C. Gilliam. ................ 6
Effect of growth Regulators on Clerodendrum thomsoniae Balf.
K. C. Sanderson and W. C. Martin, Jr ................ 7
Effect of Fungicides Applied to Polyurethane Propagation Blocks
on Rooting of Poinsettia Cuttings. Leland W. Lee, Kenneth C.
Sanderson and John W. Williams. ... ......... . . . . . . . . 8
Rooting of Poinsettia Cuttings Treated with Various Fungicides
in an IBA-Talc Powder. Leland W. Lee, Kenneth C. Sanderson and
John W. Williams. .... .......................... 10
I
November Through May Propagation of Photinia
x fraseri Tip Cuttings with IBA and NAA
Fred B. Perry, Jr.
Nature of Work: Terminal cuttings 5 in. (12.7 cm) long from Photinia x
fraseri plants were made November 18, 1981, December 
18, 1981, January
18, 1982 and March 18, 1982. Leaves from the basal 1/3 of each cutting
were removed and a light wound 0.5 cm wide was made on the lower 2.5 cm
of the stem. Treatments consisted of dipping the base of the cuttings in
talc preparations of NAA or IBA containing 5% Benlate@. 
The talc pre-
parations were: NAA at .25%, .50%, .75%, and 1.00% + 5% Benlate; IBA at
0.5%, 1.0%, 1.5%, and 2.0% + 5% Benlate; and a control of talc 
+5% Benlate.
Cuttings were then inserted into an open bench 6 in. (15.24 cm) deep
containing a moist medium of sand and peat (1:1 v/v). The medium pH was
adjusted to 5.5 using dolomitic limestone. Intermittent mist was scheduled
to be on 2.5 seconds every 5 min. during the daylight hours. A randomized
coQmplete blQck design was used with 40 cuttings per treatment per cutting
date and 4 replications. A minimum bottom heat temperature of 700 F was
maintained.
Cuttings were allowed to remain in the propagation bench only two
months after which time they were removed and evaluated for rooting per-
cent and quality of roots (roots score). Cuttings were then heeled into
the bench after evaluation.
Results and Discussion: The effect of cutting date from November 18 to
Marcfh 18 did not significantly alter rooting percentages although over-
all rooting dropped from November to December by 50% and increased to
slightly above the November level by March.
There was a highly significant rooting response to the addition of
rooting hormones. No non-treated cuttings rooted in November or December
with 2% and 5.6% rooting in January and March respectively. However,
rooting averages of 42% and 57% were obtained for NAA and IBA respectively
over this time with a monthly high of 83.6% for 1% NAA and 75.8% for 2%
IBA in November.
Cuttings replaced in the propagation bench eventually rooted in
large percentages by June. This i*ndicates that cuttings taken this
time of year would best be treated with 2% IBA and allowed to remain
undisturbed in the propagation bench under mist at least three months or
more.
Postmergence Control of Grass Weeds in Field Grown Ornamentals
C. H. Gilliam, C. T. Pounders, and T. Whitwell
Nature of Work: The control of broadleaf and grass weeds is a major
problem in the production of field grown ornamentals, even though pre-
emergence applied herbicides are usually used. Preemergence applied
herbicides often fail to control weeds adequately because of improper
timing and rate of application, weather conditions, and volatilization.
Currently, nurserymen utilize hand labor to hoe weeds that preemergence
applied herbicides do not control.
In 1980, preliminary tests by Auburn University with BASF 
9052 (Poast?),
a postemergence applied herbicide, showed this material to be safe on a
number of ornamentals when applied over the 
top of the plant. Three post-
emergent herbicides were compared in 1981 by the Alabama Agricultural
Experiment Station for control of grasses and plant phytotoxicity. 
The
three herbicides tested were Poast (BASD Wynadotte Corporation, Parsippany,
N.J.); Fusilade (ICI Americas Inc., Goldsboro, N.C.); and RO-8895 (MAAG
Agrochemicals, Vero Beach, FL.). 
Each herbicide was applied at 
three rates;
0.25, 0.50, and 1.0 lb./A ai on June 15, 1981 and 10 days 
later. In the
first study plants tested included Juniperus chinensis 'Nick's Compact',
flex crenata 'Rotundifolia', and Taxus cuspidata grown in local nurseries
at Crossville, Alabama. The junipers had been in the field 3-4 years and
were heavily infested with coastal bermudagrass (Cynodon dactylon).
'Rotundifolia' holly liners had been planted in the spring, and were
infested with common bermudagrass (Cynodon dactylon). 
Taxus had been grown
2-3 years in the field and was infested with yellow nutsedge (Cyperus
rotundus). None of the herbicides tested controlled nutsedge. When the
first application was applied, the bermudagrass was about the height of
the junipers (2'-3'). At the second application date, only a few live
sprigs of bermudagrass 
were observed.
Results and Discussion: All three herbicides resulted in excellent con-
trol of bermudagrass (coastal or common) regardless of the application
rate,(Table 1),(data not shown for common bermudagrass). With the 
exception
of Poast at the 0.25 1b./A ai rate, all treatments provide greater than
90 percent control through the middle of October. No further evaluations
were made after that time.
There were little or no phytotoxicity on plants tested. Phytotoxicity
only occurred on the junipers growing in the coastal bermudagrass. The
chlorosis that occurred after the herbicide treatments may have been the
result of sunscald, since the interior portions 
of the plant where the
chlorosis was most evident had been heavily shaded before the grass died.
At the 60-day evaluation most plants no longer exhibited chlorotic symptoms.
A second study evaluated the effectiveness of one application of these
three herbicides at the same rates on Juniperus horizontalis 'Plumosa'
(Andorra juniper) and J. chinensis 'Nick's Compact'. Treatments were applied
on July
control
species
1, 1981 and evaluated 14 and 60 days later for percent grass
and phytotoxicity. There was no phytotoxicity on either of the
tested.
All treatments except RO 13-8895 at the 0.25 lb./A ai rate resulted
in 90 percent control of common bermudagrass after 14 days,(Table 2). At
60 days only Fusilade and RO 13-8895 provided 90 percent grass control at
the 1.0 lb./A ai rate when one application was made. Additional research
is being conducted to determine minimum rates necessary for season-long
control, and to further screen these materials for phytotoxicity to woody
ornamentals. It appears that a second application applied when the 
grass
is 2-6" tall at the quarter to half pound rate when regrowth occurs may
provide adequate season-long control with minimum chemical usage.
Table 1i, Effects of 2 applications 
of post-emergent herbicides 
on percent control of
coastal bermudagrass and phytotoxicity in field 
grown junipersz
Percent control of bermudagrass
Rates Poast 
Fusilade RO 13-8895
lb./A ai Days after application 
Days after application 
Days after application
14 30 60 14 
30 60 14 30 
60
0.0 0 0 
0 0 0 0 
0 0 0
0.25 96 100 74 
100 100 96 100 
99 100
0.50 100 100 
91 95 98 100 
100 100 100
1.00 100 99 100 
96 100 100 100 
100 100
Phytotoxicity
0.0 1.0 1.0 1.0 
.1.0 1.0 1.0 i.u 
1.0 1.0
0.25 1.3
y  
1.0 1.0 2.0 2.3 
1.0 1.3 1.5 1.0
0.50 2.3 2.0 1.0 
3.0 2.3 2.0 2.0 2.3 
1.5
1.00 2.3 2.0 1.5 
4.3 3.3 2.0 4.3 
3.0 1.8
ZApplications were made at ten day intervals, and evaluations made 14, 30, and 60 days
from the second application.
YRating scale used to evaluate phytotoxicity was 
as follows: 1 = no damage, 2 - slight
chlorosis, 3 
=
chlorosis, 4 
=
foliar burn, 5 
=
25% defoliation.
Table 2. Effects of 
1 application of post-emergent 
herbicides on percent 
contro. ol
bermudagrass in field grown juniper
z
Rates 
Poast 
Fusilade 
RO 13-8895
1b./A ai Days after 
application 
Days after application 
Days after application
14 60 
14 60 
14 60
.25 90 
53 91 
79 68 
29
.50 94 
74 94 
87 93 
85
1.00 94 
85 98 
97 100 
93
ZThere was no phytotoxicity 
on any of the plants.
Fungicide Evaluation for Azalea Petal Blight Control 1981
A. Hagan and C. Gilliam
Nature of Work: Registered and experimental fungicides were evaluated for
the control of petal blight caused by Botrytis cinerea on 'Hexe' azaleas
under greenhouse conditions (Table 1). The plants were potted in a 1:1
peat and Bagasse soil mixture with a pH of 5.3. Approximately two weeks
before the fungicides were applied, the azaleas were removed from cold
storage and placed in a greenhouse in order to force the plants to flower.
Plants were arranged on benches in a randomized complete block of 3 repli-
cations with 3 plants per replicate under a polyethylene tent. Fungicides
were applied to the foliage to run-off with a Root-Lowell 3 gallon sprayer.
Shortly after the fungicides had dried, a suspension of 85,000 B. cinerea
per mil was applied to the foliage with an ASL air flow pump-u sprayer.
The incidence of petal blight and fungicide phytotoxicity was rated after
10 days.
Results and Discussion:. Control of azalea petal blight by RP26019 25E and
Chipco 26019 50W generally was superior to that provided by the other fungi-
cide treatments (Table 2). However, all fungicides evaluated significantly
reduced the incidence of azalea petal blight. Symptoms ol phytotoxicity
on azalea blossoms ranged from necrotic flecks on Manzate 200 80W and
Benelate? 50W treated blossoms to ringspots and marginal necrosis on
Bayleton
? 
50W, RP26 19 25E, Chipco 26019 50W, and Daconil? 75W treated
blossoms. Damage to blossoms was heaviest on plants treated with
Bayleton 50W and RP26019. 25E. No symptoms of phytotoxicity were observed
on the leaves. Chipco 26019 50W provided the best combination of petal
blight control and low phytotoxicity.
5
Table 1. Name, source and composi tion of products evaluated for
- control of petal blight on 'Hexe' 'azalea
Product Source Composition
Bayleton 50W.. .
RP26019 25E
Chipco 26019 50W.
Benlate 5OW. ....
Daconil 2787 75W.
Ma nzate 200 80W.
Mobay Chemical Corporation
Kansas City, Missouri 64120
Rhone-Poulenc Chemical Co.
St. Joseph, Missouri 64504
Rhone-Poulenc Chemical Co.
St. Joseph, Missouri 64504
E. E. dupont de Nemours and
Co., Wilmington, Delaware
19898
Diamond Shamrock Croporation
Agricultural Chemicals
Division, Cleveland, Ohio
441-14
E. 1. duPont de Nemours and
Co. , Wilmington, Delaware
19898
50% 1- (4-chl orophenoxy)-
3 3-dimethyl-1l(1l-N-1,2,
4-triazol-l-yl )-2-butanone
25% 3-(3,5-dichlorophenyl)
-N- (1 -methyl ethyl ) -2,4-
di oxo-l -imi* dazol i di ne-
carboxami de
3-(3,5 dichlorophenyl)-N-
(methyl ethyl )-2,4-dioxo-l-
imidazolidine carboxamide
(methyl -1-butyl -carbamoyl
-2-benzimi dazol e
Tetrachloroi so-phthal onitrile
Maganous ethylene
bi sdithiocarbamatCe
Table 2. Disease incidence and phytotoxicity of 'Hexe' azalea flowers
treated with various fungicides.
Treatment and *Disas incidence Phytotoxict
rate/00gal ....... % blighted flowers % flowers damaged
Check 31 cZ 0Qa
Chipco 26019 50W 1.0 lb. 11 b 5 abc
Chipco 26019 50W 2.0 lb. . 4 ab labc
RP26019.25E 1 qt.........4 ab 14 c
RP26019 25E 2qt............... a 29 d
Benlate 50W 2.0 lb........12 b 9 abc
Manzate 200 80W 1.3 lb. . 10 b 2 ab
Daconil 2787 75W 2.0 lb. 0 0 10 b 11 bc
Baj'leton 50W 2.0 lb........7 ab____ 28 d
Z Values followed by the same 
letter are not statisticall 'Y 
different from one
another at the 5% level according to Duncan's multiple range test.
6
Fungicide Evaluation for Botrytis Petal Blight of Geranium 1981
A. Hagen, R. Shumack and C. Gilliam
Nature of Work: Registered and experimental fungicides were evaluated for
the control of petal blight caused by Botrytis cinerea on 'Springer Scarlett'
geraniums under greenhouse conditions (Table 1). The plants were grown in
a Vergro soil mix consisting of peat moss, vermiculite, perlite and calcined
clay at a pH of 7.0. All flower clusters were removed several weeks before
fungicide application to insure nearly uniform and simultaneous flowering
on all plants. The geraniums were arranged on benches in a randomized
complete block of 3 replications with 4 plants per replicate. Fungicides
were applied to the plants to run-off with a Root-Lowell pump-up 3 gallon
sprayer. The blossoms on most flower cluster had just begun to open at the
time the first fungicide application. All treatments were sprayed a second
time 7 days after the first fungicide application. The incidence of petal
blight and phytotoxicity was rated 7 days after the second fungicide
application.
Results and Discussion: All fungicide treatments significantly reduced the
incidence of Botrytis petal blight on geraniums. The level of control pro-
vided by Chipco? 26019 50W and RP26019 25E was superior to that of Benlate?
50W. One fungicide, RP26019 25E proved to be moderately phytotoxic to
geranium blossoms.
Table 1. Name, source, and composition of products
control of petal blight of geraniums
evaluated for
Product 
Source 
Composition
RP26019 25E . ......
Chipco 26019 50W . .
Benlate 50W . . .
.Rhone-Poulenc Chemical Co.
St. Joseph, Missouri 64504
Rhone-Poulenc Chemical Co.
St. Joseph, Missouri 64504
E.I. duPont de Nemours and
Co., Wilmington, Delaware
19898
25% 3- (3,5-
dichlorophenyl )-N-
(1 -methyl ethyl )-2,4-
diozo-l -imi dazol idine-
carboxami de.
3-(3,5-di chl orophenyl)-
N -(I -methylethyl )-2,4-
dioxo-l-imidazol idine-
carboxamide
(methyl -1 - (butyl carbamoy)
-2-benzimidazole
Table 2. Disease incidence and phytotoxicity of 'Springer Scarlett'
geranium flowers treated with various fungicides
Disease Incidence Phytotoxicity
Treatment and rate/110 gal. % blighted flowers % flowers damaged
Chipco 26019 50W 1.0 lb.............. 10.0 cz 1.4 d
Chipco 26019 50W 2.0 lb. ........... .. 11.5 c 3.3 cd
RP26019 25E 1.0 qt. ............ .. 10.7 c 10.8 b
RP26019 25E 2.0 qt. .............. ... 8.1 c 22.0 a
Benlate 50W 2.0 lb. ..... ........... 17.4 b 6.2 c
Check - ... .......... 40.4 a 0 d
ZValues followed by the same letter are not statistically different from one
another at the 5% level according to Duncan's multiple range test.
Effect of Growth Regulators on Clerodendrum thomsonia Balf.
K. C. Sanderson and W. C. Martin, Jr.
Nature of Work: Clerodendrum thomsoniae Balf. plants were tested for their
response to 1-allyl-l-(3,7-dimethyloctyl)-piperidinium bromide (piproctanylium
bromide), butanedioic acid mono (2,2-dimethylhydrazideO (daminozide), 2-
chloroethylphosphonic acid (ethephon), 2-chloroethyltrimethyl ammonium
chloride (chlormequat chloride, CCC), 2,3-dihydro-5,6-diphenyl-1 ,4-oxathiin
(oxathiin, UBI-P293), sodium salt of 2,3:4, 6 bis-0-(1-emthylethylidene) =
O-l-xylo-2-hexulofuranosonic acid (dikegulac), 6-(benzylamino)-9-
(tetrahydropyranyl)-9H-purine (PBA), 2,4-dichlorobenzyltributylphosphonium
chloride (CBBP), n-undecanol plus isomeric alcohols (TD 6773),a-cyclopropyl-
a-(p-methoxyphenyl)-5-primidine methanol (ancymidol), and methyl-2-chloro-9-
hydroxyfluorene-9-carboxylate(chloroflurenol.
Results and Discussion: Of the chemicals tested ancymidol drenches, granules,
or sprays were the most effective in retarding plant growth without distortion.
Chlormequat, chloroflurenol, dikegulac, ethephon, oxathiin, and n-undecanol
were less effective in restricting growth. Generally, piproctanylium bromide
and CBBP were ineffective in retarding Clerodendrum growth. Ancymidol increased
the number of flower stalks per plant, whereas ethephon reduced flower stalk
number. Chlorflurenol completely inhibited flower stalk development.
Effect of Fungicides Applied to Polyurethane Propagation
Blocks on Rooting of Poinsettia Cuttings
Leland W. Lee, Kenneth C. Sanderson
and John C. Williams
Nature of Work: Work by Peterson 
(6) has indicated that drenches 
of
fungicides on phenol formaldehyde rooting cubes prior to rooting of
pnsettia, Euphorbia _ulcherrima Willd., caused rooting inhibition.
ther workers using different propagation media have found no inhibition
Qf rooting due to the use of fungicidal drenches at the start of pro-
pagation 5,6,8) Even stimulation of rooting 
is found in the literature
'(2?3,7). Since studies on the effect of fungicides 
on poinsettia root-
i ng often have been devoid of statistical analysis further 
work was
suggested.
Polyurethane propagation blocks (Choice Rootwell manufactured b
Jiffy Pots of America, West Chicago, L) were employed as a roQting
medium. Blocks were dipped into a fungicide suspension for 5 sec and
drained. The base of the cuttings were treated with a 0.1% indolebutryic
acid (IBA) in talc powder (Hormodin #1) from Merck, Rahway, NJ)and then
inserted into the blocks. Cuttings were taken from 
stock plants of
'Annette Hegg Lady' grown outdoors. They were sprayed with a 1:18 
(v/v)
dilution of 5.25% sodium hypochlorite in water prior to harvest. Steam
pasteurization of benches and disinfestation of tools with 1:9 (v/v)
5.25% sodium hypochlorite and water were employed to assure that experi-
ientation was done under "sterile" conditions. 
The root cubeswere placed
n abench that had hardward 
cloth covering a gravel 
bottomand misted for
3 sec each minute from 8:30 am. to 5:30 p.m.
Treatments consisted of 599 mg/liter each of fenaminosulf 
35 WP,
ethazol (5-ethoxy-3-trichloro-methyl-1,2,4-thidiaxole) 
30 WP, PCNB
75 WP, benomyl 50 WP and ferbam 76 WP; 75 mg/liter 
of metalaxyl 25 WP;
37 mg + 300 mg/liter, respectively, of metalaxyl 25 WP + benomyl 50 WP,
metalaxyl 25 WP + PCNB 75'WP, metalaxyl 25 WP + ferbam 
76 WP; 300 mg +
300 ag/liter, respectively of fenaminoulf 35 WP + PCNB 76 WP, fenaminosulf
.35 WP ? BenQmy.l 50 WP, et 
azol 30 WP ? benomyl 50 WP; 
and 599 mg + 599
mg/liter of ethazol 30 WP + PCNB 75 WP. A water 
dip was used as a control.
Concentrations of fungicides were selected on 
the basis of manufacturer's
recQmmendations and preliminary studies.
Cuttings were stuck on Sept 2 and root was measured 
on Sept 30.
Rooting was measured by countiny the number of roots 
that came out of the
bottonm of each root cube. This method was found to 
be superior to
slicing the root cube to count the roots.
Results and Discussion; The control (no fungicide dip) produce significantly
greater root counts than all fungicide treatments. The metalazyl plus
ferbam, ferbam and benomyl dips were among the better treatments (Table 1).
Treatments containing fenaminosulf produced notably'lower root counts.
The observation 
that all fungicidal 
dips inhibited 
rooting agrees
with the work of Peterson''(6) but not with that of Tayama et al. (8).
These differing conclusions could be due to differences in media sterility,
fungicide retention in the media, or quantities of fungicide applied.
Ta yama et al. (8) never mentioned the amount or mode of the fungicide appli-
cation nor did they report experimental variability encountered so that
differences could be evaluated.
Fenaminosulf and
experiment (Table 1).
in part with the work
PCNB were notable for producing poor rooting in 
this
This disagrees with other results (5,8) but agrees
of Boodley (1) and Lee (4).
These results indicate that the application of fungicidal suspensions
to polyurethane root cubes-at the time of cutting propagation is deteri-
meontal to poinsettia. Rates used in the present study 
would provide disease
control. Lower reates of fungicide should be investigated. for disease control
and root inhibition.
Fungi ci deZ
Control
Metalaxyl 25WP
Ferbam 76WP
Benomyl 50 WP
Ethazol 3OWP +
Ethazol 3OWP +
Ethazol 3OWP
Ethazol 3OWP ?
Myetal1axyl 25WP
Metalaxyl 25WP
Metalaxyl 25WP
PCNB 75WP
*Rate
(mg/liter or mg +
mq/l iter)
+ Ferbam 76WP
PCNB 75WP
eCNB 7SWP
B enomyl 5OWP
t Benomyl SO0WP
+ PCNB 75WP
Fena)-ninusulf 35WP -i iBenomyl
50wP
Fenaminosulf 35WP
Fenaminosulf 35WP*+*PCNB*75WP
37 + 300
599
599
300 + 300
300 + 300;
599
300 + 300
37 + 300
37 + 300
75
599
300 + 300
599
300 + 300
Roots per
roo tcu be
27,05a
20. 45b
18.2Obc
17. 42bc
16. 47bc
16. 35c
16. 22bc
15. 94bc
15. 7Obc
15. 44bcd
14.42bcd
12. 65cd
11 .O6cd
10. l9cd
8.05d
ZControl treatment consisted of a 5 sec. dip in water. Other treatments consisted
of 5 sec. dips in water-fungicide suspension. Commercial names: metalaxyl = Sub-
due, Ferbam = Fermate, Benomyl=Benlate,[thazol Truban, PCNB = Terrachior
and Fenaminosulf = Dexon.
YMeans in colwns followed by the same letter(s) are not significant at
5% according to Duncan's multiple range test.
_.. . I 'i ? ___
IU
Literature Cited:
1. Boodley, J. W. 1968. Poinsettia 
propagation and fungicides. N.Y.
State Flower Grow. Bull. 274:4-5.
2. Hocking, P. J. and M. B. Thomas. 1979. Effect 
of IBA in combination
with thiram, captan and benomyl on the rooting of four ornamental
species. New Zealand J. of Expt. Agr. 7:263-269.
3. Hocking, P. J. and M. B. Thomas. 1980. Rooting of cuttings of
Senecio greyi: effect of IBA in combination with DMSO, benomyl
and captan. New Zealand J. of Expt. Agr. 8:49-54.
4. Lee, L. W. 1982. Effect of fungicides on the rooting of poinsettia
Euphorbia pulcherrima Willd. cuttings. MS Thesis. Auburn Univ., AL.
5. Kuack, D. L., H. W. Tayama, J. C. Peterson, and P. A. Francasso.
1981. Effect of various fungicides on the rooting of poinsettia,
cv. :Annette Hegg Dark Red'. Ohio Flor. Assn. Bul. 
610:6-7.
6. Peterson, J. C. 1981. More perspectives on the use of fungicides
during poinsettia propagation. Ohio Flor. Assn. Bul. 622:7-8.
7. Snyder, W. E. 1966. Hormone-fungicide combinations in rooting.
Proc. Intern. Plant Prop. Soc. 16;267-272.
8. Tayama, H. K., D. C. Kiplinger, and T. C. McDowell. 1969 Effects
of dexon and terraclor on rooting of poinsettia cuttings. Ohio
Flor. Assn. Bull. 479:4-5.
Rooting of Poinsettia Cuttings Treated with Various
Fungicides in an IBA-Talc Powder
Leland W. Lee, Kenneth C. Sanderson
and John W. Williams
Nature of Work: The poinsettia, EuphOrbia ulcherrima Willd., is prone
to fungal disease infections during propagation 3 . Thus, Ecke and Matkin
(3) have recommended the addition of a fungicide in the rooting powder.
Fungicides such as benomyl (methyl 1-(butyl-carhomoy!)-2-benyimidazole-
carbamate) and ferbam (ferric dimethyldithiocarbamate) can stimulate (16,
19), or inhibit (6,7,1I,18) rooting. Fenaminosulf (sodium-p-dimethylamino)
benzediazo sulfonate), ethazol (5-ethoxy-3-trichloromethyl-l,2,4-thiadiazole)
and PCNB (penta chloronitrobenze) have been implicated in inhibition 
of root-
ing (1,11,14.17) although other studies indicate otherwise (8,12,20).
Since the effects of fungicides on poinsettia rooting are not well 
known, the
influence of various fungicides and various fungicide concentrations 
on root
initiation and development of poinsettia cuttings was studied.
11
Cuttings were taken from field grown stock plant of 'Annette Hegg
Brillant' and propagated on September 1. Cuttings were stuck in 27 x 54
x 6-cm plastic flats containing coarse perlite. Flats were placed in a
shaded greenhouse (21.1 klux or less) with natural ventilation. Treat-
ments consisted of dipping the basal 1.25 cm of the 5 - 7.5 
cm cutting in
0.1% IBA, talc, and various percentages of fungicide by weight. Treatments
Included IBA-talc plus 5, 20, and 67% of fenaminosulf 35 WP, metalaxyl
(N-(2,6-dimethylphenyl)-N-methoxacetyl-alamine methyl ester) 25 WP, benomyl
50 WP, ethazol 30 WP, ferbam 76 WP, PCNB 76 WP, and 10% ethazol 30 WP +
10% PCNB 75 WP. The control was 0.1% IBA and talc. There were 2 treat-
ments with 3 replications of 7 cuttings each in a completely randomized
block design. Mist, 3 sec per 60 sec, was used from 8:30 a.m. to 5:30 p.m.
during propagation. Four weeks after propagation the rooting was evaluated
by visual grading (scores) and root dry wt. Visual grading (scoring) of
rooting was done on a 7 point scale with 1 = no roots or callus, 2 =
c allused, 3 poor rooting, 4 = poor to moderate rooting, 5 = moderate
rooting, 6 = moderate to heavy rooting, and 7 = heavy 
rooting. For root
dry weight measurements, medium was removed from the roots prior to
severing from the shoots and drying at 750C. for 24 h.
Results and Discussion:
The control, all 5% fungicide treatments except the funaminosulf treat-
ment, and the 20% metalaxyl treatment produced cuttings with similar root-
ing scores and root dry weight (Table 1). Rooting scoresand root dry
weight of all other treatments were significantly reduced compared to the
control supporting Synder's (19) observation that higher concentrations of
fungicide inhibited rooting. Inhibitory 
results reported in other research
work (6,7) may have been due to excessive amount of 
fungicide applied. Ferbam
was notable for not causing great decreases in rooting even at the 67% concen-
tration. Other researchers have found similar results with ferbam (6,19).
Fenaminosulf was noted to cause reduced rooting even at low concentrations.
This result agrees with earlier work by Boodley (1) and other work by Lee
(13). No stimulation of rooting was observed in the present study. Work
by Hare (5) has suggested that even 5% concentrations can produce inhibition
that can cancel 
out any physiological 
stimulation of 
rooting produced 
by the
fungicide. Root "stimulation" reported in other studies (16, 19) may have
been due to the fungicidal activity of the material and not to any physiological
effect of the fungicide on the plant.
It is concluded from the results of the present study that fungicide
application as a powder at the time of cutting propagation is not recommended
if the medium is initially disease free and later contamination can be prevented.
In certain disease situations, low concentrations of fungicide could be
incorporated into a poinsettia rooting pwoder providing the causal pathogen
and the disease control specificity of the fungicide are recognized. For
example, ferbam (9,10,12) would only provide control of Rhizoctonia solani
Kuehn. whereas benomyl (15) is effective against Rhizoctonia, Bottytis cineria
Kopf. Also, metalaxyl (2), ethazol (21) and fenaminosulf 7l) are effective
against Phytium spp., however metalaxyl (2) is a more reliable control for
Phytophthora parasitica Dast. than ethazol or fenaminosulf (9,10,21).
Further research on combinations of these fungicides and others or on a
12
broader spectrum fungicide is needed for complete fungicide protection
against pathogens during poinsettia propagation.
Table 1. Rooting indexes and dry weight of
treatment with fungicide powders
poinsettia roots after
prior to rooting.
Fungicidez Commcrcial Rate Rooting Root 
dry wt.
name (%) index (g)
Control --- 6.28aX 1.08aX
Benomyl 50WP Benlate? 5 
5.90abc 0.90abc
20 4.62d-h O.50d-g
67 2.95i 0.21g
Ethazol 30WP Truban 5 5.38a-f 0.73a-e
20 4.76c-g 0.60b-f
67 4.33e-h 0.48d-g
Ethazol 30WP + PCNB 75WP 10+10 5.24a-g 0.64b-f
5 4.75c-g 0.58c-f
20 5.00b-g 0.64b-f
67 3.47hi 0.36fg
Ferbam 76WP Fermate 5 6.24ab 0.95ab
20 5.86a-d 0.88abc
67 5.57a-e 0.77a-e
Metalaxyl 25WP Subdue 5 5.63a-e 0.83a-d
20 5.33a-f 0.69b-f
67 4.00Ohi 0.41lefg
PCNB 75WP Terrachlor? 5 5.38a-f 0.73a-e
20 4.14gh 0.48d-g
67 4.81c-g 0.63b-f
z Control treatment consisted of 0.1% in a talc base with no fungicide. Other
treatments had various percentages of fungicides and 0.1% IBA in a talc base.
y Rooting scores were 1 = no roots or callus, 2 = callused, 3 = poor rooting,
4 = poor to moderate rooting, 5 = moderate rooting, 
6 = moderate to heavy
rooting and 7 = heavy rooting.
x Means in columns followed by the same letter(s) are not significantly different
according to Duncan's multiple range test at 57% level.
Literature Cited:
1. Boodley, J3. W. 1968. Poinsettia propagation and fungicides. 
N.Y.
State Flower Grow. Bull. 275-6.
2. Ciba-Geigy Corporation. 1980. Experimental 
fungicide subdue.
Technical Release. 3 p.
3. Ecke, P., Jr., and 0. A. Matkin. 
1976. The poinsettia manual,
3nd ed. Paul Ecke Poinsettias, Encinitas, 
Calif.
4. Englehard, A. W. and R. C'. Plo
4
tz. 1979. Phytophthora crown and
stem rot, an important new disease of poinsettia. 
Proc. Fla. State
Hort. $oc. 92:348-350.
5. Hare, R. C. 1981. Improved rooting powder 
for chrysanthemums.
HortScience 16:90-91.
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in combi-
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benomyl on the rooting of four
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C. Peterson, and P. A. Fracasso. 
1981.
Effect of various fungicides on the rooting 
of poinsettias, cv.
'Annette Hegg 
Dark Red'. Ohio 
Flor. Assn. Bul. 
610:6-7.
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MS Thesis, Auburn Univ.,
Auburn University, AL.
14
14. Lambe, R. C. 1980. Comparison of granules and wettable powder
formulations of fungicides for phytophthora root rot. Proc. SNA
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Exten. $ervice. AQ-108.
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