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DIRECTORS COMMENTS
N THIS ISSUE
Tillage Practice Helps Avert Soil Compaction Problems_3
The announcement recently by Presi-
System Visually AssessesMPine Seedlig Qality 4 dent Muse of the establishment of a
Public "Opinons Offered on Private Forests'}__ _ _ 5 Food Technology Institute at Auburn
, , y, w 4provides many challenges and opportunities
Immune StatuA R KIJ" t~f'erer .s'St-udi.d 
6
Immue Satuof KU uffeersStuied_________________ 6 for those of us in the Experiment Station.
1PM Strategy Effectively Controls Smokybrbwn Cockroaches 7 The Food Technology Institute (FF1) is
Granular an association of scientists from the Colleges
GranlarInsctiideAC n ga 'm BeefiialInsctsii 
eants aJof 
Agriculture, Engineering, 
Sciences and
Strawberry Variety 'T'ests Identify Best Berries9 M a a V M c a
Solid Waste Becoming aNeResource___ 10 the School of Human Sciences. The FI
Dobl idwllCu~aisReuc ne~ Ue nBrierHoss'_ povides opportunities for research to im-
Double Sidea sr l a douses~1IEweC~C'OUe 11 p
prove food safety, develop value added
Disease Transmission ia Ebband Flow Systems Analyzed 12
Nitrogen Rates and Plant pacing Affect Collard Production 13 ties, improve marketing strategies for food
Advetisng ncrase th Sae o Liv Cafis ______________ 14 producers, and provide technical support
Advertising Increae tleS e of iveiCa fie r 14
for developing new food-related industries
Rotating Soybean Cultivars MainainsYigelds ______ 15
Which Chiggers Attack Humans in Alabama? 16 In announcing establishment of the Ff1,
Dr. Muse noted that it has more potential to
ON THE COVER. Business is booming at Auburn University's fee-fishing pond and positively impact on the State's economy
live-fish market, especially after an advertising campaign that has increased than any program currently underway at
sales up to 50%, see story on page 14. Auburn University. By developing new
food industries that better utilize cornmodi-
ties produced in Alabama, the FTI can create
U P C 0 M I N G E V E N T S 
many new jobs and generate millions of
additional dollars of new income annually.
June 23 Horticulture Field Day, E.V. Smith Research, Shorter As the primary research component of
July 1 Fruit and Vegetable Field Day, Chilton Area Horticulture Substation, the FTI, we in the Experiment Station 
are
Clanton 
excited about the opportunities this new or-
July 13-16 American Peanut Research and Education 
Society Meeting, Huntsville ganization provides. It 
provides an ideal
July 22-24 Alabama Farmers Federation Commodity Conference, Birmingham foufrreachndxtsinom -
July 29 Cotton Field Day, Tennessee 
Valley Substation, Belle Minafoufrreachndxtsi 
-om -
August 4 Agronomy Field Day, E.V. Smith Research 
Center, Shorter nents of a land 
grant university like Au-
August 12 Field Crops Field Day, Prattville Experiment Field 
burn-to work together. The ultimate ben-
August 17 All Commodity Field Day, Sand Mountain Substation, Crossville eficiary of the FTI will 
be all the people of
August 19 Horticulture Field Day, Piedmont Substation, Camp Hill Alabama.
S um m er 1 9 93 V o lu me 4 0 N u mb er 2
A quarterly report of research published by the
Alabama Agricultural Experiment Station,
Auburn University.
LOWELL T. FROBISH ..... Director
DAVID H. TEEM ............. Associate Director
RUSSELL B. MUINTIFERING ... Associate Director
PAT GREEN .................. Assistant Director
ROY ROBERSON ............ Assistant Director
KATIE SMITH ............... Associate Editor
ROBYN HEARN .............. Associate Editor
TERESA RODRIGUEZ ..... Art Designer
Editorial Committee: Lowell T. Frobish; D.G.
Himelrick ,Associate Professor of Horticulture; K.L.
Bowen, Assistant Professor of Plant Pathology; E.T.
Moran, Professor of Poultry Science; L.A. Shanley,
AssistantProfessor of ConsumerAffairs; C.W. Wood,
Assistant Professor of Agronomy and Soils; H.W.
Kinnucan, Associate Professor of Agricultural Eco-
nomics and Rural Sociology; R.A. Tufts, Associate
Professor of Forestry; W.J. Moar, Assistant Professor
of Entomology; J.L. Sartin, Associate Professor of
Animal Health Research; and Roy Roberson.
EDITOR'S NOTE. Mention of trade names does not
indicate endorsement by the Alabama Agricultural
Experiment Station or Auburn University of one
brand over another. Any use of pesticide rates in
excess of labeled amounts in research reported does
not constitute recommendation of such rate. Such
use is simply part of the scientific investigation
necessary to evaluate various materials. No chemi-
cal should be used at rates above those permitted by
the label. Information contained herein is available
to all persons without regard to race, color, sex, or
national origin.
R.L. RAPER, D.W. REEVES, E.C. BURT, AND H.A. TORBERT
A CONSERVATION TILLAGE PRACTIC]
THAT RESISTS COMPACTION[ /
U ncontrolled field traffic can cause
hardpan formation which 
restricts
root growth, thus reducing plant
productivity. But cooperative
AAES- U.S. Department of Agri-
culture-Agricultural Research Service
(USDA-ARS) research indicates that using
an in-row subsoiler in a conservation tillage
practice can help avert soil compaction im-
mediately beneath the row.
An experiment was conducted at the
E.V. Smith Research Center, Shorter, to
determine the effects of tillage and traffic
treatments on physical condition of soil.
For the study, intensive soil sampling was
conducted at the conclusion of a five year
wheat-cotton double cropping system.
A special research vehicle, the USDA-
ARS Wide Frame Tractive Vehicle (WFTV),
was used as a platform to conduct all opera-
tions. This vehicle allows for a 20-foot
cropping zone (eight 30-inch rows) that can
be kept free of traffic by farm equipment. A
tractor was driven on plots designated for
traffic to simulate equipment traffic from
normal farming operations on both wheat
and cotton.
Several different tillage treatments for
cotton were used to determine the interac-
tion of traffic with tillage systems. These
treatments included:
(1) CT-SS = conventional tillage with no
subsoiling (disk, field cultivate, and plant);
(2) CT+CD = conventional tillage with ini-
tial complete hardpan disruption (disk, field
cultivate, and plant);
(3) CT+SS = conventional tillage with in-
row subsoiling (disk, field cultivate, in-row
subsoil, and plant), and;
(4) NT+SS = no-tillage with in-row
subsoiling (in-row subsoil and plant).
Each tillage treatment had both traffic and
no-traffic treatments.
Soil penetrometer readings were used to
determine the depth to the hardpan. This
measurement is important because it indi-
cates the depth of effective crop rooting.
The soil condition resulting from years
of continuous tillage and traction research
provided vital information 4
about the damaging effects
of traffic on soil that was
conventionally farmed. In
the conventional farming
system without any deep .
tillage (CT-SS), traffic ~
caused the depth to 
the hard- 20
pan to decrease by almost
22% and thecottonlintyield
to decrease more than 14% 28
(see table). 
Untraf
In the tillage 
treatment 
middl
that was completely dis- Cone index co
rupted with a V-frame traffic is appli
subsoiler at the beginning of the five-year
study (CT+CD) traffic caused the depth to
the hardpan to decrease by 35% and cotton
lint yield to decrease by 14%. The benefits
of complete disruption disappeared and
this was the poorest yielding tillage treat-
ment when traffic was not controlled.
When an in-row subsoiler was used with
conventional tillage (CT+SS), traffic did
not affect the depth to the hardpan, but de-
creased cotton lint yield by almost 9%.
With the NT+SS treatment, traffic actu-
ally had a positive effect providing a cotton
yield increase of 2%. These plots were the
most productive and had maximum yields
of any in this experiment. Traffic nega-
tively affected the depth to the hardpan
slightly, but this was less than 5%. One
reason that traffic was not detrimental in
DEPTH TO HARDPAN AND 1991 CorroN LINT YIELD
AS AFFECTED BY TRAFFIC AND TILLAGE TREATMENTS
Depth to Cotton
Treatments hardpan lint
yield
In. Lb./a.
No Traffic
CT-SS .............................. 9.1 955
CT+CD..............11.0 912
CT+SS ............................. 14.6 872
NT+SS............................. 16.9 957
Traffic
CT-SS ........................ .... 7.1 815
CT+CD ........................... 7.1 786
CT+SS .............. 14.6 794
NT+SS..................... 16.1 978
ntours for the NT + SS tillage treatment when
ed to row middles.
the NT+SS treatment was that the soil
structure was able to support the applied
traffic loads and withstand the damaging
effects of traffic. This is illustrated in the
contour plot that shows a profile of the crop
row and traffic path for tillage treatment
NT+SS subjected to traffic (see figure).
Even though traffic did compact the soil
beneath the row middle, the in-row subsoiler
provided adequate rooting depth beneath
the row.
This experiment indicated that in con-
ventional tillage systems that did not in-
clude an in-row subsoiler, traffic negatively
affected both the depth to the hardpan and
crop yields. However, when the conserva-
tion tillage practice of in-row subsoiling
was used, the resulting soil structure al-
lowed the soil to withstand the detrimental
effects of traffic. Though farmers don't
have WFTVs, they can control the negative
effects of traffic and maintain surface resi-
due cover by combining conservation till-
age with an in-row subsoiler.
Raper is Adjunct Assistant Professor of Ag-
ricultural Engineering and Agricultural Engi-
neer with the USDA-ARS-National Soil Dy-
namics Laboratory (NSDL), Reeves is Adjunct
Associate Professor of Agronomy and Soils and
Research Agronomist with USDA-ARS-NSDL,
Burt is Adjunct Professor of Agricultural Engi-
neering and Research Leader with USDA-ARS-
NSDL, and Torbert is Soil Scientist, USDA-
ARS, Temple, Tex.
Alabama Agricultural Experiment Station
3
J.H. WILHOIT, L.J. KUTZ, D.E. FLY, AND D.B. SOUTH
J It A _-v OW COST
ore than 1.5 billion pine seed-
ling.s ar e planted in the South
e/ Lvxry year. The success of for-
est regeneration activities is
strongly influenced by seed-
ling quality. Better quality seedlings tend
to have higher survival and groowth rates.
AAES research may soon provide a fast.
economical way to assess seedling quality.
Quality is usually assessed by exaluating
nmorphological properties. sueh as root col-
lar diameter and shoot height. However.
typical Iorest nurseries bundle and ship up
to sexeral hundred thousand seedlings per
day, making quality assessment of' e'ery
seedling impractical. Nurseries therefore
se sampling techniques to monitor seed-
ling quality. but the measurement of large
numbers ol seedlings is still required. Re-
seairch on seedling quality improxement also
involves the measuirement of large numbers
of seedlings.
Measuiing seedlings by hand is slo and
subject to ineasurement and recoirdine er-
rors. As ailahle electronic measurement
methods are either destructixe or nearly as
slowx as manual measurements because ex
tensive operator input is reqLired for every
seedling measured. AAS investigators
haxe developed a low-cost machine vision
systemi to quickly measure and record pine
seedling plroperties.
The PC-hased system. xxhich uses
Charge-Coupled-Device (CCD) video cam-
eras and digital image processing tech-
niques. ielies on backlighting and manual
seelling placement in a specified location
to simplify image processing requirements.
An i mportantl feature of the system is the
use of multiple cameras to maximize reso-
lutions li different seedling parts. The
systemi measuires root collar diameter, shoot
height. and shoot and root projected areas.
Seedling measurements are acquiired and
automatically recorded with a single flip
of a switch.
Tests were condicted with both two-
carne ra and three-camera eon Iifieurations of
the system. The two-camera conf icuration
had one camera focused
on the iroot coll ar area.
while the othercamera had
a field 1)1 iexx encompass-
in- the entire seedline.
The three-camera 
con fi 
f
ration had one camera fo
cused on the root collai
area, one oi the shoot area.
and one oin the iroot area.
This configuration ixie"
higher image resolution,
for the shoot and root pio-
jected area measurements
Tests exvaluated how well
machine vision measure-
ments of root collar diam
eter and height compared PC-based mach
to man ual measurements
and hoxw welI machine xision protected
area measurements compareul to dry xeights
and to projected area measurements ob-
tained dlestructively with an infrared line-
scan dex ice.
For the manual comparison tests, each
seedling xas measured by two persons so
that the x ariability inherent in manual inea-
surements couild be assessed. Root collar
diameter and height results showed good
agreement between machine vision and
manual measurements. Variability fhr ma-
chine xision measurements compared to
manual measurements was no creater than
variability for manual measurements com-
pared to each other.
Projected area measurements, which can-
not be measured by hand, are of interest
because of their potential for predicting
xeight. surface area, and xolume. Machine
xision shoot and root projected area mea-
surements xere moderately conrelated to dry
weicht measurements. The line scan de-
vice, or area meter, was used as an indepen-
dent standard to asscss the accuracy of the
machine xi sion projected area measurements.
Machine x ision and area meter projected
area measurements were highly correlated.
The two-camera system had a much
shorter cxcle time than the three-camera
ilne vision system for measuring pine seedlings.
sxystei (about six seconds per seedling xer-
sus IX seconds per seedling). but both of
these cycle times can be reduced suibstan
tially by upgrading the micropiocessor used
in this study. A fast cycle time is desirable
for makinc measurements on a large num-
her of seedlings, but manual seedling place-
ient xill require at least a few seconds for
each seedling, so there is a limit to how
rapid the cycle time can be.
The higher resolution of the three-can
era configuiration did not imprxove the accu-
racy (f projected area measurements as
expected although it is difficult to make a
direct comparison because separate tests
were conducted with each confiur ation.
Foi seedling measurements in at nursery pro-
duction setting. the two-camera configura-
tion may be better because of its simplicity
and speed. For research purposes. there may
be additional measurement requirements.
especially related to roots, that can be met
xith a three-camera configuration.
This study demonstrated the feasibility
of rapidly measuring pine seedling morpho-
logical pioperties using low-cost machine
vision technology.
Wilhoit and Kutz are Assistant Pirofessors and
Fly is former Research Graduate Assistant of
Agricultural Engineering: South is Associate Pro-
lessor of Forestry.
Aluabani Agricultural E pc r-itnce o Station
i ~. Y i. ~ LILI. L11*ib~j~ ~3LXSLi,,~
12 r,.~-, rr,, TTrCI:~, (5,\ c:rr24
J.C. BLISS
PUBLIC OPINIONS PRIVATE FORESTS
erccie cld eirionmental etfects are
the Iitmnus test for public approx al
of forestry practices. according to
an AAES study funded paltl h
the Alabama Unix ersities/T enncs
see Valley Authority Research Consortiurn.
A statewide telephone surey of 1.)07
randchmly, se I eeted Iou sehold s indicated th at
Alabamians those who own forests and
those wh o do not care about enx ironimein-
al coiiservatioin.
P'erhaps the nost hotly debated issue in
forest management is the tradeoff between
envi ronimental proitection andi private prop-
crtyx riehts. The study indicated that most
Alabamians want a halance of these values.
but one that faxvors the envx iron ment.
[Iully 841r agreed with the statement.
"Prixvate property rights are important but
only if they don't hurt the enironment." A
majority supported government regulations
to proteet natural beauty. streams and wet-
lands, and threatened and endangered spe-
cies. Most of the forest owners interv iewed
su ppo irted regulations to poteet wetlands
and endangered species. However. strong
majorities also supported compensation for
Iorest owners xhen regulations cause them
to lose money.
[he survey further indicated that much
of the public accepts cutting trees as a neees-
sary forest manage ment praetiee. Sexenty-
two percent agreed that "Trees are like any
othei crop. and they should he eut and re-
planted to provide consumer products.''
Morover. 55( felt that the amount of tree
cuttincg in their area is 'about right."
This apparenit acceptance is conditional.
hoxx ex er. upon the lack of adxverse enx iron-
mental effects. A central concern for the
environment appears to drive opinions
about timber harrvesting and other forest
iaiage ment practices.
(learcIutt ing remains at contested prac-
tice. with slightly over half the pub!ic ap-
proying its use on private lands. Similarly,
half approxved of the use of prescribed I ire
to cont rol comipeting vegetation on prixate
land. In contrast, chemical
weed control. although loh,
used in aearieultuie, has h ct
to xin xidespread public
acceptance for forest man
agemcnt. Only 33r agreed '
xxith the practice. 4 G
Those who oppose clear
cutting. prescribed
burnin. and chemical
xeed control base theii Fully
opposition 
on the 
per- 
84/
ception that the prac a
tices destroy ildlife. agreed
deplete dwindling 
re- With 
the
sources, or hax e othei
negative enxironiien
tal consequences. "Private
Unf amiliaritx wih proper
forests and the cm iron-
mental effects of man- rights
agement 
actixities 
are
likel!' caused at least i r
soliC of this disap i
proval. For example. but
although Alabamai for only
est acreage incieased
dramatically oxer the if they
past 5) years. 
77(/( be- 
don't
liexe forest land de-
creased ox er that time. hur
Asked how often 
the
landowners spray pine 
environmi
forests with chemicals.
61( said thex did not
know. and 26(/ think
spraying is done at least yearly. In tact, the
most intensixely managed piiie plantations
in the South are sprayed at most three times
dui ng their entire Ifi etiime of about 35 years.
Although most respondents were not
xelI informed about forestry, they were
fairly educated: 85( completed high school.
and half had some college training. Respon
dents were from all walks cf life, including-
professionals, managers entrepreneurs and
others. Opinions xw ere based not onlx on at
limited knowlledge of forestry bct also oi
personal observations, expertise
in other areas. and news coxerage
of enxironmental issues.
Forestry professionals may find in these
results a xaluable lesson: forestry actixities
perceix ed to protect or enhance the ennviron-
ment are likely to enjoy public approval.
Both the piblic and forest oxners are likely
to disapprove of practices that do not match
this perception. The profession faces dlal
challenges: to continue to develop envi-
ronmentally frienlly managemcnt meth-
ods and to educate a skeptical public.
Bliss ks Assistantt Profoessor- of For esnrv.
Albaniam At,'ric ltiura/ Exerei-nent Station
S.S. GROPPER AND H. C. CHAUNG
IMMUNE STATUS OF CHILDREN
WITH PHENYLKETONURIA
Infants born in hospitals throughout
Alabama and the U.S. have their
heels pricked about 72 hours after
birth to obtain a blood sample that is
tested for the presence of an inher-
ited disorder called phenylketonuria or
PKU. PKU is a lifetime condition in which
the ability of the body to breakdown pheny-
lalanine, an amino acid found in protein, is
impaired. The incidence of PKU in the
United States is about one in 12,000.
If not treated, PKU results in severe men-
tal retardation, but if diagnosed and treated
with diet therapy, there are no harmful ef-
fects. Infants diagnosed with PKU are put
on a diet that restricts phenylalanine intake.
Infants and children with PKU must avoid
high-protein foods such as milk, eggs,
cheese, yogurt, meat, fish, and poultry, and
must limit their intakes of other foods con-
taining protein such as breads, grains, pas-
tas, and vegetables. Thus, simple food com-
binations such as cereal with milk, or a
sandwich with peanut butter, cheese, or
lunch meats cannot be consumed.
Specially designed formulas referred to
as medical foods provide infants and chil-
dren with the majority of their daily needs
for protein, vitamins, and minerals. Diets of
children with PKU are very restrictive in
the choices of foods allowed, and often as
the children get older compliance with the
diet diminishes, resulting in higher plasma
phenylalanine concentrations. Adherence
to the diet, however, can also lead to im-
paired mineral status and alterations in
plasma amino acid concentrations.
Deficiencies of amino acids such as phe-
nylalanine and tyrosine, minerals such as
iron, selenium, and zinc, and other nutrients
diminish immune system function. For ex-
ample, nutrient deficiencies can result in
decreased production or function of: (1) an-
tibodies that help destroy foreign substances
in the body; (2) complement, a group of
proteins that work with antibodies to de-
stroy foreign substances in the body; (3)
interleukins that influence blood cell func-
tion and ultimately antibody production;
and (4) white blood cells that can directly
kill or assist in the destruction of foreign
substances. Children with PKU may be at
risk for impaired immune system function
because of the PKU condition itself or be-
cause of the diet therapy used to treat PKU.
Investigators at the AAES have begun to
assess selected aspects of immune system
functioning in children with PKU on diet
therapy.
Twenty-two children with PKU were re-
14
12
10
_J
8
6
4
2
0
Concentration of three major antibodies (IgG, IgA, IgM) in children 
with and without PKU.
cruited from four centers that treat PKU in
the United States. Blood samples were ob-
tained from each child to examine cellular
and humoral immune system function. Re-
searchers measured white blood cell num-
bers and concentrations to examine cellular
immunity, as well as concentrations of anti-
bodies, complement, and other proteins in-
volved in humoral immune function.
Immunological data of PKU children
who were maintaining normal plasma phe-
nylalanine concentrations were compared
with those children with PKU who were not
adhering to diet and thus had relatively high
plasma phenylalanine concentrations. Data
from children with PKU were compared
with published data from age-matched chil-
dren without PKU. While no differences in
immune status were observed between chil-
dren maintaining normal versus high
plasma phenylalanine concentrations, as a
group children with PKU had lower con-
centrations of certain antibodies than chil-
dren without PKU (see figure).
No significant differences in plasma
concentrations of other antibodies, comple-
ment, and white blood cells were found be-
tween children with and without PKU nor
within children with PKU with differing
plasma phenylalanine concentrations. No
correlations were found between plasma
phenylalanine concentrations and immuno-
logical parameters.
Results of this research suggest that mod-
erate differences in plasma phenylalanine
concentrations do not appear to affect se-
lected immune system parameters. This
does not mean that it is safe to exceed the
recommended maintenance of plasma phe-
nylalanine concentrations, since plasma
phenylalanine concentrations in excess of
normal ranges can lead to declines in arith-
metic, language, and perceptual skills;
shortened attention span; impaired short-
term memory; and visual motor perception
and motor coordination problems. Further
studies are needed to investigate causes for
lower than normal concentrations of anti-
bodies in children with PKU, as well as
causes for impaired nutrient status of chil-
dren with PKU on diet therapy.
Gropper is Assistant Professor and Chaung is
former Graduate Research Assistant of Nutrition
and Food Science (now Associate Professor of
Veterinary Medicine, National Ping-Tung Institute
of Agriculture, Taiwan).
Alabama Agricultural Experiment Station
IgG IgA IgM
L.M. SMITH, A.G. APPEL, T.P. MACK, G.J. KEEVER, AND E.P. BENSON
INTEGRATED PEST MANAGEMENT EFFECTIVELY
CONTROLS SMOKYBROWN COCKROACHES
common insect around homes in
Alabama. Control of this insect
takes many forms, including the
use of insecticidal sprays by
homeowners and professionals. Indoor in-
secticidal sprays used by homeowners do
not effectively reduce abundance of cock-
roaches, because cockroaches residing out-
doors will reinvade when the chemicals
dissipate.
AAES research explored options for out-
door control of the smokybrown cock-
roach. These studies focused on improving
management strategies, based on the insect's
behavior, that provide effective control yet
reduce insecticide use.
Two outdoor trials were conducted to
evaluate the efficacy of two different man-
agement strategies in 18 homes in Auburn
during the summer of 1992. Three experi-
mental treatments were used: a no-manage-
ment control, a perimeter spray, and an
intergrated pest management (IPM) ap-
proach.
The perimeter treatment consisted of
spraying insecticide three feet up from the
base of the house and 10 feet out into the
yard with a power sprayer. The spray was
a wettable-powder formulation of chlorpy-
rifos at the rate of five ounces of active
Reduction in cockroach abundance, pct.
-60
' TRIAL ONE
-40
-20
0
20
40 T;0 00
60
80
100 10 
0 10 
20 30 
40
ingredient per 100 gallons of water. This is
one approach used by professional pest con-
trol operators in Alabama.
The IPM treatment combined two tac-
tics: applying an insecticidal spray to crev-
ices around the outside of homes and re-
moving litter and debris from within a foot
of the house to remove cockroach habitats.
Crushed gravel was used near the homes to
replace the debris. After application of
treatments, cockroaches were sampled
weekly at each house to assess changes in
their abundance.
Cockroach abundance was reduced ap-
proximately 40% in the first trial with no
difference noted between the IPM and pe-
rimeter treatments (see figure). However the
IPM treatment was safer and less expensive
because it reduced chemical usage by 75%.
In the second trial, the rate of chlorpyri-
fos in the perimeter treatment was increased
to the mid-range of recommended rates,
eight ounces per 100 gallons of water. Three
additional tactics were included in the IPM
treatment. The first additional tactic was an
application of a pelletized ant-and-cock-
roach bait containing 0.5% chlorpyrifos,
which was applied within three feet of
homes with pine straw, fallen leaves, or ivy,
and next to other cockroach habitats, such
as garden borders, large rocks, or railroad
50 -10 0 10
Days after application
Reductions in cockroach numbers for each trial.
ties. The second tactic added was the appli-
cation of a gel bait containing 2% hy-
dramethylnon, which was applied in shel-
tered crevices, such as in porch corners,
under ledges, in crawl space gratings, and
under garage doors. The third tactic was the
release of insecticidal smoke in out-
buildings and crawl spaces. The smoke
contained 12.5% permethrin.
More than 80% reduction in cockroach
abundance was achieved in the second trial,
nearly twice as much as in the first trial. In
addition, the IPM treatment reduced abun-
dance longer than the perimeter treatment
(see figure). The IPM treatment maintained
cockroach populations below those in the
perimeter treatment for the duration of the
trial, using only one-fourth of the insecticide
of the perimeter treatment.
This second IPM approach proved ef-
fective because it took advantage of several
aspects of cockroach behavior. Insecticidal
sprays and the insecticidal smoke kill cock-
roaches where they hide during the day.
Pelletized and gel baits attract hungry cock-
roaches to feed on insecticide in their nor-
mal feeding areas, close to where they hide.
Finally, removal of litter reduces hiding
places next to the base of homes and reduces
cockroach activity near doors and other en-
trances. By targeting management tactics
at cockroaches where they
hide and forage, use of in-
secticide can be decreased
and cockroach control can
.atment
eter 
be maintained 
for a longer
period than by employing a
standard perimeter spray.
Thus, the IPM treatment ap-
pears tobe an effective, safe,
andeconomicalwayto man-
age outdoor cockroaches.
Smith is Post Doctoral Fel-
30 40 low, Appel and Mack 
are Asso-
ciate Professors, and Benson is
Assistant Professor of Ento-
mology; Keever is Associate
Professor of Horticulture.
Alabama Agricultural Experiment Station 7
T. P. MACK
j1AICN ULAR INSCTICIDES HARMLI.
ARTHROPODS IN PEANUTS
L csser cornstalk horers can reduce
peanut yield and quality. espe-
cially in hot, dry weather, when
potpulation outbreaks are likelx to
occurf. Recent AAES research in-
dicates that insecticides applied too early
may lose etectiveness before outbreaks oc-
cur, and may have a double negative impact
by killing oll beneficial insects that prey on
lesser cornstalk borers.
In AAES research, grarnular insecticides
were especially damaging to beneficial
arthropods such as striped carw igs anid fire
ants that livx on the soil sulrace. wheie the
granules are applied. It is important to
maintain an abundance of beneficial
arthropods in peanut fields because they pro-
x ide cheap and effective control of many
insect pests, including lesser cornstalk bor-
ers. Destroying beneficials also increases
the abundance of some insect pests in (ther
crops.
Field experiments were done at the
Wiregrass Substation. Headland. Sun-run-
ner peanut seeds were conventionally
planted in a I)othan sandy loam soil, usingi a
randomized comiplete block design in both
years. with four replicates of fix e treatments
and a nontreated control. Plot size was
eight rows wxide by 5) teet long. Herbicides
and fungicides were applied according to
Alabamna ('ooperative Extension Service
recommendat ions. Insecticides used were
Lorsban I J 1 at two pounds of active
ingredient (a.i.) per acre. MocapR 15G at
three pounds of a.i. per acre. [\IifonaCR
I OG at two pounds ot 
a.i. pet acre.
Fortress? 1OG at one-hall pound of
a.i. per acre. CounterB 15G at two
pounds of a.i. per acre, and a
nontreated control. Treatments
were applied at peanut flowering
with a small-plot granular appli-
cator.
Pittall traps were used to sample
for arthropouds that liv e on the soil
surface. Pitfall traps were used be-
cause granular insecticides remain
on the soil suiface. so their greatest
effects should be on arthropods that
live and craw I on the surface of the
soil. Each trap was conposed of
two plastic drinking cups that were
buried to their tops in the soil, filled
one-third full with antifreeze, and
covered xx ith a 12-inch aluminum
pie plate held above the ground
with nails. The pie plate was hung over the
traps to deflect water. Traps vere monitored
weekly for at least sexen weeks after applica-
tion. Contents ot traps xere remoxed re-
turned to the laboratory, aid identified.
Applications of granular insecticides had
very transitory effects on insect pests such
as the corn earxxorm and fall arin xorm.
The applications had no effect on beneficial
arthropods such as bigeyed bugs and spiders
that inhabit the foliage (Table I).
Predators such as striped earwigs and red
imported fire ants were the most abundant
beneficial insects. Abundance of these
predators declined in sonie treated plots tor
Pesticide programs designed 
to kill harmful insects,
such as this adult male lesser cornstalk borer, can also
kill beneficial insects.
as long as one nionth. which would increase
the probability of economic darage from
insect pests such as the lesser cornstalk
borer (Table 2).
A potentially serious result of applying
a granular itsecticide to peanuts is the re-
duced abundance of fire ants and striped
earwigs. These two predators were the most
abundant arthropods sampled. so the nega-
tix e effects of oiranular iisecticides could
increase the probability ot economic damage
from lesser cornstalk borers and other insect
pests. These results underscore the need for
timely applicatfons ot insecticides based on
scouting.
Mack is Associate Professor ot Entonology.
TABLE 1. ABUNDANCE OF SELEC1Ett PREDATORS UY TREATMENT COMBINED OVER Ai L
S \ti't i DATES. I 990
Insecticide Imported Bigeyed Spider Spider Ground
fire ants' hugs (calopy)' (soil-dwelling)' beetles'
Nontreated 2.......... 20.8 0.8 0.2 1.7 3.9
Iorsban .............. 4.2 .6 .2 1.2 4.3
Mocap .......... 7.3 1.3 .1 1.3 4.4
DU tinate ............ 9.6 .0 .3 1.7 4.5
Fortess ................ 8.8 1.1 .3 1.7 52
Counter .......... 2 .6 .4 .0 4.5
Number per 0 rap per week from pitfall traps.
'Numher per six row-feet per week, Irom beat sheets.
TABLE 2. ABUNDAsNCE OF STRIPED EARNN IGS I OR 35 DAYS At til TRFL SItEN I
oN Jit 5, 1990
Days atter treatnment
Insecticide 5 12 19 28 35
Nontreated ........... 14.9 8.6 23.) 112.5 100.5
ILorsban ............... 3.9 4.1 13.1 89.4 10)26
Miocap ............... 29 5.3 2(.3 90) 135.1
D) fo ate .............. 5.4 6.6 25.5 97.9 133.1
IFortiess .............. 1.5 69 36.8 1(119 132.1
Counter ................ .6 2.1 10.8 89.1) 130.9
A lubmni rAu'icultiru/ Lvjwtimcllewl Station
I i . I2r
D.G. HIMELRICK, W.A. DOZIER, JR. A.W. CAYLOR. J.A. PITTS. M.H. HOLLINGSWORTH, AND W.B. WEBSTER
MAI TED RZow STRAWBERRY VARIETY PERFORMANCE
IN CENTRAL AND NORTH ALABAMA
eletring thre best perlti iiru S .ri ctx
Sis crucial to the success (If a cor-
mercial strawberry operation. Al-
th ughi miany xvarietires are axvailable,
only a fewx will povide high yields
arid superior fri t quality.
WhleI the econoImics ot Successful pro-
duetiori make high yields a primary conisid-
crationi x hen selecting x aricties. additional
fruit quality characteristics rmust be conisid-
erecd in the final decision. Other citerra in-
elude cornsisteriex of annrural cropping. x igor.
runner-riak inrg ability. disease resistance.
and othle r pl ant penforrmance tactors: as wAelI
aS her- ixse, firmiiness sugear content. tiax or.
and othe icrhiuit quLial ity characteri stics.
Varieties arec categorized as early-, mid-
or late-season in ripening. Ditffer ences iii
lie fii st hiarx est date usuiallIy do no( t xvar-y
great ly amronrg xvariet ies. The gr-eate st dillfer-
ence iii ripeing is the tirie (If peak hiarx est.
wh lich may x ary sexven to 10) days betweecci
the earliest andI latest ripening x arieties. Ini
somiie xvears the dif fererice ini the ipeinrg
seasonis may be short and peak harx est sea-
soils oIt the xvarieties ovxerlap.
Straxx brrx xvariety trials we rc condiulctedl
at the (Chrltori A-rea Horticultuire Substation
(CAHI S) ini 1horsbx. Nor th Alabama Hor-
tICUItUirC Suhsationl (NAHS) ini Cullmian.
and~ ITenniessee Valley Substation (TVS) iii
Belle Miria.
In the f irst e-xperirient, 21 xvarietics were
plantedl at the NAHS and TVS. lIn a seconrd.
16 x arieties 'a erec planted at the CAHS arid
TVS. Ini a third test. 23 xvarieties xwere
planted at the CAHS.
The x arieties cx aluated xxere Earlibelle.
Sunrrise. Far liglow. Titan. Preludue.
Surecrop. Pocahontas, Sco(tt, Cardinal.
Ark6086 . Allstar. Atlas. Douglas. Parajo.
Vista. Rosanine. Sentinel. Ar k6686. A-rkinig.
Delite. Tennessee Beautx. Redchiet. Ti(Iea.
Albri tto n, A pollo. C hand ler. A iko. Guard-
iam. I lonce, C Lester. Sequoia. LateeLdx
\m Mllate.
I ar-e seasonal and location fluctuationis
\\ e I seen in miiany important performuance
loir acteristieS, Such as yield and berry sirc.
]'be seveni ox erallI best v arijetiCs we re
larligloxk. Sunrise. Titan. Allstar. Cardinal.
Scott. and Dcllite (see table).
Scx eral top-yielding x arieties wxerc not
in the top sC\ en duc to additronal undesir-
able traits. F-or example. Tennessee B~eaurty
has a relatixvely soft, small berry and ave r-
aiee dessert arid processing quality . Apollo
prodirces Sterile pollen and variable x relds.
as we ll as being droug~ht Susceptible. Alter-
natrxely, somrie ax er age-xieldriie xarictics.
such as [-arligloxx are listed because of
other char acteristrcs, such as earliness and
exceptiorially good flavor and processing
quality for freezinrg.
Moire detailed inflormation conrcerinrg
the 3 xvarireties tested in this Study is pre-
sented ini \AA S Bulletin 619," Pertotrunce
(it Sti- ax brrx Cultix ars in Central arid
North Alabama Growxn on the Matted Roxx
Sy stem..
Professor - and (,i\ or is Research Specilist of
HoutICUliure: Ptti. Hoinesxiirth, and W\ehster
are Superintendents of the Chitton Area Hoirti-
culture. North .\lahana Horticulture, and Tennes-
see Valley substations. irespects ely.
OP' tI iiRMiI STRAW\ iii RRSv V~ Sll hiSs i Ri< i OS F SI \i \ Yi SRS 550U TuREE LOt ArIONS
Vai lit
t-arli'tii ..............
t au i . . . .. . . . .. . . .. . . .
Sunse ............ ...
A llt at ...............
Carn n . .............
S co t . .. . . .. . . .. . . .. . . .
D elit .. . . . .. . . . . .. . . . .
Torat Harvst Ai verage tPerceini heirs
s ietd seaisin fruit soiluile liiniiiess'
w~eight solids'
Lb./a
7,170
8.761
8&439
8.806
8.3(02
9.582
10.040
F-.rN
Early
E-ail s
Mid
MIid
Mid
Lt ae
Gr,,ot
6.9
9.8
9(0
1012
10.2
92
10.0
Degrec
exterior
colo~r
4.5
4.2
4.2
3.6
4.5
4.4
3.9
Degree
itrio(
clorl
4.2
3.6
3.7
2.5
4.1
4.1
2.7
Ltisteid iii order of ripening.
'One oun tie eqa it29 grams.
'The hither rthe peicent of SOluble solids. the sw~eeter ihe berry.
I irnniess dutne: I = ver s~oft. 10) = ery firm.
tDeuiee of color: I =green. 5 = dark red.
Al/u/bm,, Agricirutua F_.r1eijnew .Statioum
T.A. MCCASKEY, S.D. ZHOU, S.N. BRITT, AND R.C. STRICKLAND
CAN SOLID WASTE BECOME A RESOURCE
INSTEAD OF A LIABILITY?
The U.S. discards approximately
200 million tons of municipal solid
waste (MSW) each year, creating
many disposal problems. Auburn
University and Tennessee Valley
Authority (TVA) researchers have demon-
strated a promising method of recycling
MSW into a valuable raw material that can
be used to produce biodegradable plastic.
Landfills and incinerators are now the
primary means of MSW disposal, but they
may cause water and air pollution. And
while MSW production is increasing, the
capacity to handle
it is decreasing.
M00Many 
landfills
and incinerators
lodegradable have been closed,
and sites for new
ki!istic may disposal facilities
eplae are 
often difficult
to locate. Recy-
.... cling is one of the
he 1 5. . .
most promising
. ways to manage
ilon. . .MSW 
and reduce
f.S 
its environmental
Simpact.
DMVO lORMI !i 
Newsprin 
t,
Iastik 
wood, cardboard,
and yard waste -
s d in 
which comprise
he U.S.. 56% 
of all MSW
- are primarily
very year. made 
of plant fi-
bers called cellu-
lose, a network of
thousands of simple sugar units. These
wastes can be broken down into individual
sugar units, chiefly glucose and mannose,
using sulfuric acid. The sugars can be fer-
mented by microorganisms to produce a
variety of fuels and chemicals. Microbial
fermentation has been used for many years
to produce ethanol from the glucose found
in corn.
Recently, a 100% biodegradable plastic
was manufactured from lactic acid and ap-
TABLE 1. E
proved for use by the Food
and Drug Administration. 
This 
Bacteria
evaluate(
product may replace some of
the 15 million tons of conven-
tional plastic used in the U.S.
L. arabinos
every year. This development 
L. arabinos
has stimulated interest 
in pro- L. arabinos
ducing 
large quantities 
of in- 
L. pentos
expensive lactic acid. MSW L. pentosus
could provide 
a low-cost 
L. plantaru
L. xylosus 4
source of sugars for lactic acid
production, in addition to re- cMSW
ducing the volume of waste 
in 
2
One p
landfills. 
milliliters.
AU and TVA researchers
TABLE 2. O
are developing the technology
to use microorganisms to con-
vert MSW 
to lactic 
acid. The 
Fetiment
waste used in these experi-
ments was newsprint that had Days
been treated with 2% sulfuric 0.....
acid at 250?F causing the pa- 1.................
per to break down (hydrolyze) 2.......
3 .................
into its component sugars, 4.......
yielding 4.1% sugar. 5.................
Since the hydrolyzate may 'Total su
contain compounds 
harmful was added.
to lactic acid-producing 
bacte- 
One pou
ria, it is treated with calcium
hydroxide and filtered. Nitrogen supple-
ments, which the bacteria require for growth,
also are added.
An evaluation of eight types of bacteria
showed that one in particular had the poten-
tial to produce high levels of lactic acid
from MSW (Table 1). Culture L. pentosus
227 produced 0.187 pound of lactic acid
from one gallon ofhydrolyzate (2.24 grams
per 100 milliliters).
To further improve the ability of the cul-
ture to produce lactic acid, the sugar con-
centration of the MSW hydrolyzate was
increased to 8.2% and the hydrolyzate was
buffered by adding 5% calcium carbonate.
Since lactic acid is produced from sugar, the
increased sugar should improve lactic acid
production. The higher buffer capacity
should help alleviate inhibition of lactic
VALUATION OF LACTOBACILLUS CULTURES FOR PRODUCTION
OF LACTIC ACID FROM MSW
1
SSugar used Lactic acid Sugar to
d produced lactic acid
conversion
g/100 mL
2  
g/100 mL
2  
Pct.
us 787 ........ 3.04 1.86 61
us 788 ......... 3.01 1.82 60
us 813 ......... 3.33 1.70 51
us 531........ 3.18 1.67 52
227 ............ 3.63 2.24 62
473............. 3.84 1.93 50
m 422 ......... 2.95 1.96 66
449 ............ 1.83 0.82 45
hydrolyzate contained 4.1% total sugars and no added
rbonate.
ound equals 454 grams; one gallon equals 3,785
PTIMIZATION OF LACTIC ACID PRODUCTION CONDITIONS FOR
CULTURE L. PENTOSUS 2271
ation Sugar Lactic acid Sugar to
conversion
g/100 mL
2  
g/100 mL
2  
Pct.
................... 0 0 0
................... 2.00 1.54 77
................... 6.23 5.32 85
.................... 7.49 6.50 87
................... 7.54 6.05 80
................... 7.54 6.04 80
gar concentration was 8.2%, and 5% calcium carbonate
and equals 454 grams; one gallon equals 3,785 milliliters.
acid production caused by the higher acidity
associated with increased yields of acid.
Under these conditions, culture 227 pro-
duced 0.542 pound of lactic acid per gallon
of MSW hydrolyzate (6.5 grams per 100
milliliters), almost three times more than
previously demonstrated (Table 2).
Industry is exploring the production of
lactic acid from corn for the manufacture of
biodegradable plastic. However, the use of
solid waste has significant environmental
advantages. Studies are in progress to further
improve the process of converting MSW to
lactic acid.
McCaskey is Professor, Zhou is Visiting
Scholar, and Britt is Research Associate of Ani-
mal and Dairy Sciences; Strickland is Project
Manager, Biotechnical Research Department,
Tennessee Valley Authority.
Alabama Agricultural Experiment Station
10
J.L.KOON, C.A.FLOOD,JR., R.D.TRUMBULL, AND R.N.BREWER
ENERGY SAVINGS WITH USE OF DOUBLE
SIDEWALLCURTAINS ON BROILER HOUSES
Heat energy is used by broiler
producers during the first three
weeks of a growout to provide an
optimum environment for bird
survival. Depending upon time of
year, brooding energy used during this time
will range from 75% to 100% of the total
energy used for the entire growout period.
Heat supplied during the last four weeks
serves primarily to improve feed conversion
and efficiency. Since LP gas, which is the
primary source of heat utilized in broiler
houses, is expensive relative to other energy
sources, conservation is a major concern of
broiler producers.
From an energy use consideration, the
ideal poultry house would be a totally en-
closed, insulated house for the brooding
period with open curtains during the re-
mainder of the growout.
For curtain sidewall houses that are cur-
rently being built in Alabama, the portion of
the house energy losses that can be attributed
to curtain area on houses using single cur-
tains and half-house partial-area brooding is
approximately 66% of the total for the house.
The use of double curtains reduces this por-
tion of the total house energy loss due to the
curtain area to 48%. This has the potential to
reduce the overall heat loss from the house
during the first three weeks by some 35%.
A study of this concept was conducted
by the AAES during four 48-day cold
weather trials at the AU Poultry Research
Unit to show the overall effect on energy use
when using double curtains as compared to
single curtains on poultry houses. While
every effort was made to operate the sys-
tems in a manner similar to that used in
industry, the size and type of house used in
GAS USAGE FOR THE FOUR TRIALS, GAL. LP
Trial Single Double Pct. reduction
curtain curtain
Trial 1 .......... 466 357 23
Trial 2 .......... 208 187 10
Trial3 . 238 180 25
Trial 4....204 156 24
the demonstration prohibited the utilization
of partial house brooding. Because partial
house brooding was not used, total energy
consumption was higher than would be ex-
pected in a typical commercial house.
Comparisons of the relative amounts of
energy used and relative energy savings
can be made, however.
Two houses were equipped with single
curtains, and two houses were equipped
with double layers of curtain material. The
curtain material for the house containing
double curtains was installed as shown in
the figure. Air was al-
lowed to enter the
house by passing up-
ward through the air
space between the two
curtains. This method
of installation allows
recovery of a portion
of the heat loss through
the curtain material
and prevents conden-
sation of moisture be-
tween layers of curtain
material, which has
been a problem when
double curtains with
closed bottom edges
have been used. One
curtain was installed
outside the building,
and the second curtain
was installed inside.
The building wall was
constructed using 3.5
X 3.5-inch posts, thus
a 3.5-inch air space ex-
isted between the cur-
tains. Theoutercurtain Cross sectional v
was held away 
from construction 
on
the wall at the lower edge by a series of 0.5-
inch tubes.
During early brooding periods when
ventilation requirements are lowest, air
flow was through the lower opening and up
between the two curtain layers. A 1.5-inch
iev
slot opening was established at the top of
the inside curtain. Both curtains could be
lowered, and ventilation air passed through
a 1.5-inch opening at the top of each curtain
when ventilation requirements increased.
The inner curtain opening could be closed
completely when needed. Both curtains
can be lowered completely to provide a
four-foot opening for warm weather opera-
tion. The table summarizes the gas usage
for the two types of curtain material for the
four trials.
Overall gas usage for the four trials was
reduced from 1,118
gallons for single cur-
tain houses to 881 gal-
lons for double cur-
tain houses. Use of
double curtains gave
an average gas usage
reduction of 21%.
This research in-
dicates maximum
benefit of double cur-
tains will be obtained
by installation in the
wall sections of the
primary brooding
area and should not be
required for the entire
house. It also indi-
cates reduction in gas
usage, resulting from
the use of double cur-
-tains, will depend on
house construction
and time of year the
birds are grown. The
most effective use of
double curtains is dur-
w of double curtain ing the first three
Itry house.weeks 
of production,
and in most cases their use will be justified
only in the partial house brooding area.
Koon and Flood are Associate Professors and
Trumbull is former Research Associate of Agri-
cultural Engineering; Brewer is Head of Poultry
Science.
Alabama Agricultural Experiment Station
11
S.S. STRONG, C.F. DENEKE, B.K. BEHE, AND K.L. BOWEN
I RAN SMISSION OF PHYTOPHTHORA ROOT RoT IN
AN EBB AND FLOW SUBIRRIGCTION SYSTEM
ncireasln concern
a bot xxater qf al-
ity has prompted
the floriculture in-
dustry to increase
scrutiny of f ertiliz a-
lion and irrigation
practices to help re-
duce the potential 
for 
I
groundater coitaimi-
nalion from green- 
,
house runoft. Ebb and 
a
now suirrigation is
one mtethod ot control-
liia ruinoillf, hut recent
AAES research indi-
eates plant spacing is
critical in reducing
the spread of disease
Peppermint Cooler vinca gro
withi this system. with 
Phytophthora parasitica.
Ebb and flow sub-
irrigation is a closed pioduction system These s
SiVI MI N I Of PHIOPHI iIRA P0 \%AI-F( A To NON \I it rr VINCA
SP.-Vl Li ATTwo Divi \N\(iSii O \im ANDi ho rNCH
Spacing hetmeen
pots
hi.
(iooip 1. 7/16 .............
Group 2. 1 5/8 ............
C
wing on an ebb and flow bench; closest row inoculated
pores would be discharged along
with the runoff in traditional
irrigation systems, but with
Linulatiie intettiol of nonireated plants are contained and recircu-
Week 2 Week 4 
Seek 6 lated. 
The movement 
of the
root rot pathogen Phi to-
Pct. Pct. 
P. ptlihortra 
parasitico from 
dis-
6 23 60 eased to healthy plants in the
0 10 30
subirrigation system was stud-
ied in an AAES project.
that collects runoff and returns it to a tank
foi recirculation. As the surface of a leak-
proof floor or bench is slowly flooded, irri-
gation water flows around and beneath pot-
ted plants. Water is transported tp through
the growing medium by capillary action.
Altcr the sater is turned off, the irunoff is
used for the next irrigation. This labor-
saxing system conserves water and fertil-
izer decreases croundxsater contamilation
pitential, and reduces incidence of foliar
tlisease.
A possible dirasback is the spread of root
ltscase in the iecycled liquid. Some bacteria
and fungi produce spores that moxe freely
in water and can cause large crop losses.
Five-wxeek-old seedlings of Peppermint
Cooler vinca were transplanted into three-
inch pots. Six rows of plants were placed on
4 X 6f4oot ebb and flow benches. The first
row placed along the drain of each bench
was inoculated with the pathogen to serve as
an inoculum source for the five nontreated
rows. Separate benches were used to space
pots at two distances - 7/16 and 1 5/8
inches. Plants from nontreated rows were
barsested at txo-week interxals and root
samples wxere tested for exidence of
Phytophthora. Solution from irrigation
tanks also wx as tested. Plants were groxxwi on
the benches for six weeks.
By week six, root samples from 601/ of
nontreated plants
spaced at 7/16 inch
(Group I ) displayed
infection by Phyto-
phthora. while 30'4 of
those spaced at 1 5/8
inches (Group 2) ex-
hibited pathogen
growth. Diseasekilled
all of the inoculated
plants. and Phyto-
phthora spores were
detected in one of four
water tanks used.
The pathogen
moveci from the in-
oculated row to the
fifth row of nonitreated
plants on all benches
by week six a total
distance ot 17 inches
in Group I and 23 inches in Group 2.
However. only 1317c of infected plants in
Group 2 exhibited sexere root injury, com-
paied to 36% of those infected at the closer
spacing. Severe injury means at least 25%
of the root system is harmed.
The pre-packaged Canadian sphagnum
peat and perlite medium used in this study
xas steam pasteurized to allows lo moire
accurate detection of Phytophthoia by
eliminating existing pathogens. However
pastetiri/ation of Canadian peat is not rec-
ommended in commercial production be-
cause beneficial, disease-suppiessingl mi-
croorganisms also are destroyed.
Sanitation of production areas and disin-
fection of equipment reduce chances of1 a
disease outbreak. but other measures may
become necessary once a pathogen is estab-
lished in an ebb and flow system. Chemical
pesticides are commonly used in consven-
tional production systems. however ithere
are currentls no fungicides or pesticides
registered for reciiculation.
Stinn is Giaduate Research Assistant. )ckcec
and Behe are A\ssistant Pirofessors of Horticu turie:
Boms en is Assisiant Professor of Pant Patholog .
A labamai A 0/rh mltiura/ E.v1 rime n .Slution
J.M. DANGLER AND C.W. WOOD
iN I1 (RlON hAt LS AN D V it H1N-K0iV PA(AN(NS
41- _T8- ~ a
in recent year s, seed companies ha
introduced new hybrid collaids tl
are higher yielding than traditiot
open-pollinated varieties. One hbr
Blue Max. exhibited the greatest v ii
stability in trials conducted in the Sothea
Because ol the increased cost ol hybh
seed and the conv enience ot obtaining din
ity transplants. collard establishment I
shifted rom direct seeding to the use
transplants. -loseser. the effects ofx with
row spacing and nitriogen (N) fertilizer re
on collards prodnced from transplants F
not been addressed. An AAES
study focused on these factors in
the production of Blue Max and
Vates. a less expensive, open-pol-
linated vaieicty. grown i a sandy
loam soil.
Field experiments were con
ducted in the spring and tall of
1990() on a Norfolk/Oraneburg
sandy loam soil at the E.V. Smith
Research ('ente. Shorter. Treat-
ients included N rates of 0. 50. I.
100.150. and 200 potnds per acre .
supplied as anmmoniui 
nitrate.
One-row plots were used with r4
plant spacingsof 6. J. and 12 inches.
Rows were f our leet apart.
Potassiim and phosphorous
were broadcast anI incorporate at
iates determiined by the Auburn Univeis
Soil Testing Iaboratory. Half ol the N "
broadcast at planting: the remainder "x
band-appliet 3) tlays after planting. Wee
nematotes, antI othe pests were controll
accordine, to the Vegetable Pest Conti
Guide ANR-2. Plants were harvestetd or
each season ait the 21-leaf stage.
Fall yields were 4.6 tons per acre. wh
spring yielts were 2.8 tons per acre.
shown in the Ifigure. Collards usually gr(
better in the Iall when temperattres are co
However. season, N rate, and ctiltil
interacted in their effects on yieltl. In
spring. Blie Max yield increased prop
tionatel as N rates increased, butt
6 I-
Q
-64
33
a2
u.
F
I I I I I I I I 0 I
0
00
0 
0
0 
0
O
O
.9
D
D
I
150 200 0
N Rate, Ib./A
Y
itN highest Vates yield wxas obtaietl at 100
7as potnds of N per acre. Highest fall yields of
'as both xarieties were obtained with 100
As. potnds of N per acre. Howexer. Blte Max
ed yielded more at all rates of N application.
rol The superiority of Blte Max xx as espe-
ice cially exident in the control plots. where N
was not applied. The hybrid yielded ap-
ile proximately I0(01 more than Vates in these
as plots. However. it shoild be noted that Blue
rw Max pirotluces bluish-green leaves that
ol. some consumers may find objectionable.
ai Yields of both collard xarieties decreased
he from 4.0 to 3.6 tons per acre as the xx ithin-
ii roxx spacing increased trom six to nine
he inches. Yields tlid not decrease further at
50 100 150 200
AES study confirmed the high yield potential of
Max, a hybrid collard variety.
'-inch spacings.
Ailts of' these experiments confirm
iperior yield potential of' Blue Max. a
hi id. compare to an openpol litiatet cul-
mi-. Blie Max responded to the addition
wure than 100 pounds of N per acre.
I n the fall, the yield difference between
,_i tics when no tertilizer was applied is
Jdlitional evidence of the hybrid's poten-
al. Blue Max may have the capacity to
)rodtce high yields when planted as a
dotble crop without additional fertilizer.
The similar redtctions in Nielti of both
varieties xith increased xithin-row spacing
suggests the crop's response to plant spac-
ing is similar for hybrid and open-pollinated
collards.
In addition to confirming the yield po-
tential of Blue Max. the results of this
experiment establish a benchmark for N
application at 100 pounds per acre on Ala-
bama sandy loam soils. It also snggests that
high yielts of standard and hybrid collards
may be obtained at within-row spacings of
nine inches and a tour-foot row spacing.
Dangler is Assistant Protessor ot Horticul-
ture and Wood is Assistant Professor of
A'ionoms and Soils.
A Iabainu A i- ic ultirrl E xperiloc w Stationt
I
L. L. LOVSHIN AND D. R. BEAM
ADVERTISING INCREASES
THE SALE OF LIVE CATFISH
small area of water often have
problems marketing their fish to a
processing plant because the small
quantities harvested do not warrant
purchase by the processing plant. Small-
scale catfish producers have to find alterna-
tive markets for their fish. Two of the most
attractive markets for small-scale catfish
farmers are fee-fishing and live-fish sales to
area residents.
The Department of Fisheries and Allied
Aquacultures has operated a live-fish mar-
ket and fee-fishing pond located five miles
north of Auburn for 13 years. The market is
open on Saturday from 8 a.m. until noon
about 47 weeks a year. The fee-fishing pond
is open during the same time period about
32 weeks a year.
Channel catfish raised in AAES research
ponds are harvested in the fall and early
winter and stored in holding ponds until
they are sold. Enough fish must be stored to
satisfy consumer demand until the follow-
ing year's fish are large enough to harvest
in September. Often 40,000 to 50,000
pounds of fish, 8,000 to 10,000 pounds per
acre, are in holding ponds during the winter.
Holding ponds that contain over 5,000
pounds of fish per acre by the end of March
often have disease outbreaks that can result
in high fish mortality. To reduce fish mor-
tality, the weight of fish in the holding
ponds is reduced to levels that permit the
maintenance of a healthy aquatic environ-
ment.
Live channel catfish 
are THE INF
sold for 
$1.20 
per pound 
while
catfish are sold 
to the process- 
Year
ing plant for $0.60 to $0.70
per pound. Thus, profits are
higher if excess fish 
in holding 1985 .........
ponds can be sold 
through the 
1987.........
live-fish market or to fee fish- 1988.........
ers rather than to a processing 1989..
plant. To increase catfish sales, 1991 ....
a three- to four-week 
advertis- 1992.....
ing campaign 
is conducted 
be- 
Avg ....
3,:
3,1
tween January 14 and March
31. Ads are printed in the
Auburn University student
newspaper and two area . 2,500
newspapers at a cost of about
$150 per week. 
The ad cam- 
o
paign promotes a reduction in 2
the price of live catfish from
$1.20 to $1.00per pound. Ads
are printed on eitherThursday
or Friday depending on news- 1,500
paper distribution.
An average of 47,060
pounds of catfish per year and
998 pounds of catfish 
per 1,000
week have been sold from
1985 through 1992, as shown
in the table. Advertisements 
in 500
local newspapers increased
live catfish sales in 1990,
1991, and 1992 (see figure). The weight
An average of 1,468, 2,388, during, 
an
and 2,047 pounds 
per week of 
and 92.
live catfish were sold during the periods of
newspaper advertisements in 1990, 1991,
and 1992, respectively. The weight of
catfish sold during promotions increased
37, 50, and 47% over the weekly averages
for 1990, 1991, and 1992, respectively (see
table). Live catfish sold three weeks before
and three weeks after the ad campaign at
$1.20 per pound generated average weekly
incomes of $927 and $1,216, respectively.
Average weekly income received from live
catfish sold for $1.00 per pound during the
1 2 3 4 5 6 7 8 9 10
Weeks
of live channel catfish catfish sold before,
d after advertisment campaigns in 1990, 91,
ad campaigns was $1,968. Even with the
$150 per week advertisement costs de-
ducted from the $1,968 earned weekly dur-
ing ad campaigns, average weekly income
increased $891 and $602 compared with
income earned before or after the promotion,
respectively.
Additionally, advertising appears to
have a residual effect on catfish sales after
the promotion is ended, as shown in the
figure. An average of $289 more catfish
were sold during the three weeks after the ad
campaign compared to the three
rHE AAES weeks before the ad campaign.
Percent Newspaper advertisements
increase to promote 
a reduction in the
price of live catfish are a
promising method to raise cat-
- fish sales, reduce inventory in
- catfish holding ponds, and in-
- crease income.
Lovshin is Professor and Beam
is Senior Research Associate of
Fisheries and Allied Aquacultures.
Alabama Agricultural Experiment Station
LUENCE OF ADVERTISEMENTS ON LIVE-CATFIS
Sale weeks Yearly Average Av
per year sales weekly sa
sales
Lb. Lb.
... 48 47,511 990
... 41 46,907 1,114
... 48 42,510 886
... 48 46,656 972
... 46 42,180 917
... 50 46,280 926
... 49 57,948 1,183
... 48 46,489 969
... 47 47,060 998
1,468 37
2,388 50
2,047 47
1,968 45
verageweeklwcampaig~r -1Lb.
14
J.H. EDWARDS, D.B. WEAVER, D.L. THURLOW. AND J.T. EASON
ROTATING
SOYBEAN
CULTIVARS
MAINTAINS
YIELDS
ticularly corn or sorghum. has been
Ro 
a 
~i oe 
n 
t a 
n o 
s 
ro ea 
cyst
Irecognized as a valuable tool in the
mianagement of soybean cyst
nematode. Soybean cultivars that
are rcsistant to soybean cyst nematode also
have been Lised as a management tool. Con-
tinued monoculture of resistant cultivars.
however, led to the development of new
races of soybean cyst nematodes that were
able to reproduce on and reduce the yield of
previously resistant cultivars. AAES re-
search suggests that rotating resistant and
susceptible varieties may provi dc a way to
grow a soybcan monoculture and maintain
acceptable yields.
In Alabama soybean yield losses in 1992
due to soybean cyst ncmatodes, were esti-
mated to be 110,000() bushels, worth
$600,000. Reducing the loss by a small
percentage should have a beneficial effect
on net returns to the soybean producer.
An AAES study was conducted at the
Sand Mountain Substation. Crossville, to
determine the effects of various soybean
clopping sequences on soybean yield and
soybean cyst nematode numbers. The rota-
tion included soybean cultivars that were
susceptible and resistant to cyst nematode.
Cropping sequences included continuous
monoculture with the same soybean cultivar
using Essex (a susceptible cultivar). Forrest
(resistant to soybean cyst race 3), or Bedtord
(resistant to soybean cyst races 3 and 14).
These plots were compared to plots in a
two-year rotation of Essex-Forrest. Forrest-
Essex, Essex-Bedford, Bedtord-Essex
Forrest Bedf ord. Bedford Forrest. Essex-
corn. Forrest-corn, or Bedford-corn.
Soybean yields were lower when culti-
vars were not rotated compared to cultivar
rotation and rota
tion with corn 50 F 
Continuous 
20Y
(see ti('ure). Yield
of Essex was W Soy-Soy
lower when the
previous crop was Soy-Corn
Bedford rather 40
than [orrest. 15
Corn in the rota-
tion had the great- Z
est positive ben-
efit on soybean Q 30
yield. There was C 0
a oie to two - M
-10 c
bushel peracre in- Ui
crease in yield 0
when resistant 20
cultivars were
rotated with sus-
ceptible 
ones.
while there weie 5
two to four bushel
per acre increases
when soybeans
were rotated with
corn.
Soybean cyst 0- 
0 0
nematode larvae 1990 
1991 1990 1991
and cyst counts Cyst nematodes
were highest for Soybeans
continious Essex Yields and nematodes counts from various treatments 
including con-
and continuous tinuous (nematode susceptible soybeans), soy-soy (resistant and sus-
Forrest soybeans.ceptible 
rotation) and soybean 
and corn rotations.
Larvae and cyst counts were higher in the tode-infested soil is feasible when resistant
Forrest and Bedford cultivars when follow- cultivars are rotated with susceptible ones.
ing Essex.
Edwards is Adjunct Associate Professor ot
Based on these findings, it appears that 
Agronomy and Soils and Soil Scientist wxith 
the
soybean production practices that 
include US)A-ARS National Soil 
Dynamics Lab. Weave
corn in the rotation are the best means to is Professor and Thurlo 
is Associate Professor
sustain soybean yield. However, planting Emeritus of Agronomy and Soils. Eason is Super
continuous soybeans in soybean cyst nema- intendeni of the Sand Mountaii Suhstaiion.
Alabama Agricultural E.xperiment Station
G.R. MULLEN
VVHICH HIGGERS ATTACK HUMANS IN ALABAMA?
ost people haxe encountered
chiggers or 'red hugs.' and
experienced the intense itch ing
their bites can cause. but little
inform ation is axvail able regard
ing the species ot chiggers n volved. )cirinv
the past 15 years, researchers with the AAES
coldlected in formation that helped deternmin m
the species that attack hnmans and the fate
of those chiggers once they haxe attache
to ai unsuspecting host.
(higereis are tie tiny larx al stagce of mite'
ot tle fainilv Tmnbicadli. Whierteas
nyiplis and adults t these mites are Iiree
Iiin. the larvae are parasitic on manx
vertebiate hosts iicludiii mammals. birds.
reptiles, and amphibians. Chiggers seldom
cause icici discomfort to their normal hosts.
However, when they attach to atypical
hosts such as humans, their bites often
cause skin reactions, usually aiound the
ankles, wrists, waist, and othei parts of the
body where clothes fit snugly.
Identificatiois of chiggers recovered
ifro hu mans in Alabama indicate that two
species are most frequently involxcl. Nei-
ther has a common name. Oie is the eastern
forn of, Iutrombhicu/o a/frcddui'csi. the
most pesky chigger intesting people in the
easterii U.S. The other is Luuotiobi u/
lipoi sk ona, which has not been repoted to
bite humans. Although the lattei species
was found crawling on people. researcher s
are iot sure if it actually attaches aiid feeds.
On the other hand, E. (Ilf-reddu'esi was
clearly respoisible for most ot the discom-
tortiig chigger bites experienced.
A third species, E. splemle n. known to
attack humans in areas bordering marshes
and swamps - was not recovered, which is
probably due to liiited collectiins from
these particular habitats.
. ulf -c(d(uigc si was found maiily in
relatixely dry upland areas of piie. iixed
hardwoods, and second- groxth sites domi-
nated by various plants. such as blackberry
and honeysuckle. In contrast. L. liposvsian
was ound in low-lying deciduous xoods
with damp. shaded ground cover aid an
Close-up view of skin reaction to chigger bites w
swelling, and vesicle formation.
abundance of decaying logs and stumps.
Both habitats support populations of lizards.
which are preferred hosts ot these chiggers.
Both species xere generally active
throughout the summer and early tall. E.
orifr-ceddui,'ei xas recoxered in huiman cases
from early May through mid-September
and I. liporskv ana froi early July through
mid-October. . alftrcdducs comprised
7514 of the cases examined and 76(r of the
total specimens recoxerec and ideitified.
To determine what happens to chiggess
after attachmenit to a peison. indiviidual
mites wx ere monitored. In oie series of
observations, the attachmeit sites of 25 E.
afr c-ddu'esi were circled xw ith ink wi thin
1 2 limi" of ifl etatio 1 .iIh ile ie i,
ALABAMA AGRICULTURAL EXPERIMENT ST/
AUBURN UNIVERSITY
AUBURN UNIVERSITY, ALABAMA 36849-5403
Lowell T. Frobish, Director
POSTMASTER-Address Correction Requested
.naniined daily
thereafter. Within
Sthe 36irst 3 hours.
fib;. 
nine had died
while stiII attached
at their original
sitesanother nine
had detalched and
either dropped off
or ioved to an-
other, undeter-
mined location. 01
the remaining
seven attached
ith associated 
redness, iites. 
only two
xere still alive by
the fourth day. None surxvix ed tol daiy five.
Even the few chiggers that did manage to
feed did not appear to survive oi this host.
Whether the mites survived or not, their
bites caused intensely itchy skin lesions,
oftei culminating in fluid-filled vesicles at
the point of attachmet. These ohserva-
tions iidicate that few, if any, of the chig-
gers that attach to humans successfuilly
complete their feediig and go oi to de-
x elop into nsmphs. However. unless the
chiggers are killed or riemoved within a fe
hours, their bites typically cause a localied.
sometilies severe. skin irritatioi exven after
the iites have died or detached.
\TION
NON-PROFIT ORG.
POSTAGE & FEES PAID
PERMIT NO. 9
AUBURN, ALA.