I
STATION. 4
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DIRECTOR'S COMMENTS
Tm m ~YiA 1979 marks 50 years of agricultural research on outly-
ing units of the Agricultural Experiment Station. An Act of the
Legislature of 1927 authorized the establishment and maintenance
of "sub agricultural experiment stations, one upon each of the five
main large soil types of the State as represented in the Tennessee
Valley, the Sand Mountain Section,
the Black Belt, the Wiregrass, and the
Gulf Coast Area - and to provide for
the carrying on of research work on
experimental fields in different parts
of the State." During 1927-28-29,
land was obtained and facilities con-
structed for the Tennessee Valley, 9
Sand Mountain, Black Belt, Wiregrass,
and Gulf Coast substations, all of
which are still in operation, and 7 ex-
periment fields, including the Brew-
ton, Monroeville, and Prattville fields
which are still active today. The first As a
experiments were conducted in 
1929 . DENNIS ROUSE
and the data from these experiments
are in the record books of this office. Fifty years ago, 36 different
varieties of cotton were tested at the Tennessee Valley Substation
and the average yield was 503 lb. of seed cotton per acre. For this
same station, a contract is on file which shows that the total contract
price in 1928 for the construction of a superintendent's residence,
5 labor houses, a mule barn, machine shed, office building, double
garage, and a chicken house was only $17,873. Eight of these 11
buildings are still in service today.
The remainder of the present-day substations were established
after authorization by the Legislature as follows: Upper Coastal
Plain - 1944, Piedmont - 1945, Chilton Area Horticulture - 1948,
North Alabama Horticulture - 1948, Lower Coastal Plain - 1949,
and the Ornamental Horticulture Field Station in 1952.
Research on the outlying units has played an important role in
the research program of the Agricultural Experiment Station and
has made major contributions to agriculture and forestry of Ala-
bama. In addition to affording the obvious advantages of attacking
and solving problems in the particular soil type and climatic en-
vironment of the area in which a unit is located, outlying units
serve an important function of providing a link between the Agri-
cultural Experiment Station and the people of the State. Producers
can observe experimehts on such things as varieties, pest control,
crop rotations, cultural practices, and livestock under similar con-
ditions existing on their farms. As an example, during 1978, a total
of 2,300 people attended 35 station-conducted meetings and tours
held at outlying units in cooperation with. the Cooperative Exten-
sion Service staff and other agricultural leaders. Another 4,300 at-
tended 65 meetings of farm-related organizations and school class
tours. Also, numerous unscheduled visits were made.
The research at the outlying units is planned cooperatively by
department heads and project leaders at Auburn and superinten-
dents and assistant superintendents of the outlying units, with over-
all direction from the Director's office. Each experiment is planned
to fit into our total program of research. In 1978, over 500 experi-
ments were conducted on the outlying units - each in cooperation
with one or more project leaders from Auburn.
Changing priorities in agricultural research require adjustments
in the research program of the outlying units. Thus, there has been
a continuous evolution in research and we can be assured there
will be further.changes in the future. Continued emphasis will be
on applied research dealing with studies of varieties, fertilization,
pests, cultural practices, and livestock production.
Dr. Coleman Y. Ward, the new head
of the Department of Agronomy and Soils
for the School of Agriculture and Agri-
cultural Experiment Station. He fills the
position left vacant by the retirement of
Dr. L. E. Ensminger.
A native of Millican,
Texas, Ward came to Au-
burn from the University
of Florida where he was
./ chairman of the Depart-
Sment of Agronomy, a posi-
tion with responsibility for
teaching, research, and ex-
tension activities. At Au-
burn he will direct teach-
ing and research in agronomy and soils.
Before joining the Florida faculty in
1974, Ward had been professor of agron-
omy at Mississippi State University for
13 years. His work there involved re-
search on forage and pasture crops and
turfgrass management. His earlier experi-
ence, in Florida, Texas, and New Mexico,
involved various areas of crops and soils.
Ward received B.S. and M.S. degrees
from Texas Tech University, and holds
the doctorate from Virginia Polytechnic
Institute and State University. His prin-
cipal fields of specialization include soils,
forage crops and turfgrasses, and bio-
chemistry-plant physiology.
HIGHLIGHTS of
Agricultural Research
SPRING 1979 VOL 26, NO. I
A quarterly report of research published
by the Agricultural Experiment Station
of Auburn University, Auburn, Alabama.
R. DENms RoUSE -Director
STANtEY P. WiLsoN....Associate Director
CHAs. F. SIMMONS .AssAistant Director
T. E. CORLEY.. Assistant Director
E. L. McGAw -Editor
R. E. STEVENSON_ Associate Editor
Ro ROBERSON __ Assistant Editor
Editorial Advisory Committee: STANLMEY
P. WILsoN; C. A. FLOOD, JR., Assistant
Professor of Agricultural Engineering;
J. D. HARPER, Associate Professor of En-
tomology; NEIL R. MARTIN, Associate
Professor of Agricultural Economics and
Rural Sociology, AND E. L. McGRAw.
Information contained herein is available
to all without regard to race, color, or
national origin.
ON THE COVER. New bull test station gives
added dimension to performance testing pro-
gram.
,ffice b 73, Ei
Electronic key on neck chain allows bull to feed in assigned bunk
only. Thus, individual feed consumption can be measured.
PERFORMANCE TESTWG started at Auburn University in
1951. That first test had 19 bulls - 13 consigned by Alabama
breeders and 6 from the Agricultural Experiment Station
herd. Average daily gain (ADG) was 1.94 lb. and weight
per day of age (WDA) averaged 1.93 lb., table 1. The high-
est performance, ADG of 2.50 lb. and WDA of 2.40 lb., was
made by a Hereford bull consigned by C. W. Gantt, of Titus.
Performance at this level in today's test would be below aver-
age for both traits.
Since that modest beginning, 2,491 bulls have been tested,
and 1,684 have qualified for sale. In addition, several high
performing bulls have been retained by their owners for
breeding purposes.
Requirements for bulls to enter the test 
have been increased
periodically in an effort to reduce compensatory gain and to
improve test reliability. Compensatory gain makes individuals
appear to perform at unrealistically high levels. Requirements
were increased as follows: WDA was increased to 2.00 lb. in
1960, to 2.10 lb. in 1966, to 2.20 lb. in 1970, and to 2.30 and
2.50 lb., respectively, for British and large breeds in 1973.
Weaning weight records were required in 1961, and mem-
bership in Alabama Beef Cattle Improvement Association be-
came mandatory in 1964. These requirements are still in
effect.
Success of the program is evidenced by the steady increase
in participation and improvement in overall performance of
test bulls. For example, ADG went from an average of 2.24
lb. during 1952-59 to 2.74 lb. average for 1970-76, table 1.
Increases for WDA, conformation score, and selling price for
the same periods were 2.04 to 2.59 lb., 11.9 to 13.3, and $407
to $874, respectively.
It appeared that performance had reached a plateau by the
mid-1970's and that continued progress would be hard to
aphieve as long as bulls were tested under existing environ-
mental conditions. A new bull test center designed to over-
come environmental limitations was built in 1977. This new
facility has the unique capability of not only testing bulls for
their ability to gain weight, but also to measure individual
feed consumption. This measurement is accomplished with-
out confining bulls in separate pens. Each feed bunk has an
electronic panel contained in an especially designed door that
allows access to the feed. Each bull has an electronic key on
a plastic chain around his neck that will open the door to his
assigned feed bunk only. Thus, individual feed consumption
can be recorded for determining feed efficiency (FE). Bulls
learn to open their assigned door in a 7- to 10-day training
period before the test begins.
The 96-capacity barn is divided into eight pens with 12
feeding bunks each. Each pen is connected to a dirt loafing
TABLE 1. SUMMARY OF Autmx U vnsrrY PERFORMANCE
Test Bulls Bulls Conf.
years on test sold ADG WDA score
2  
Pnce
No. No. Lb. Lb. $
1951__. 19 0 1.94 1.93 10.2
1960-69. 
954 
733 2.46 
2.30 
12.7 
595
1970-76._ 986 547 2.74 2.59 13.3 874
1 
Performance data are for sale bulls only.
2 10 = average Good, 11 = high Good, 12 = low Choice, 13
= average Choice, and 14 = high Choice.
STEADY PROGRESS IN
PERFORMANCE TESTING
T. B. PATTERSON, Dept. of Animal and Dairy Sciences
TABL. 2. COMPARATIVE PERFO MANCE: FOR LAST Two TEsT
s
'
Test Bulls Bulls AD WDA Feed Final Conf. Price
years ton sold ADG WDA 
eff. wt. score riceyrs test
No. No. Lb. Lb. Lb. Lb. $
1976-77- 119 58 2.51 2.53 .... 1,065 14.0 736
1977-78 .... 84 60 3.12 2.78 7.3 1,170 13.4 1,021
Junior .. 26 23 3.14 2.85 6.7 1,092 13.4
Senior .. 58 37 3.11 2.75 7.5 1,205 13.4
Data are for the last year at North Auburn Beef Unit (1976-
77) and first year at the new test unit (1977-78).
lot. Electronic scales in the adjoining working pens are used
for periodic weighing of the bulls during the test. These
scales are self balancing and show animal weights on a dis-
play panel.
Comparative results of the first year in the new facility and
the last year at the old site are given in table 2. A total of 84
bulls finished the 1977-78 test, of which 60 were sold. The
ADG and WDA, respectively, were 3.12 and 2.78 lb. in the
new facility, a substantial improvement over the 1976-77
values of 2.51 and 2.53 lb.
Average FE, which is calculated as pounds of feed required
to produce a pound of gain, averaged 7.3 lb. for the 84 bulls.
The range was from 5.6 lb. for a junior Charolais that had
ADG of 3.19 lb. to 11.6 lb. for a senior Angus that gained
only 1.86 lb. per day. These data indicate a correlation be-
tween ADG and FE.
Because of lower maintenance requirements, younger,
smaller bulls will require less feed per unit of gain than will
older, heavier bulls, table 2. Even though there was no dif-
ference in ADG (3.11 vs. 3.14 lb.) between senior and junior
bulls, the junior bulls that averaged 1,092 lb. required 0.8 lb.
less feed per pound of gain than the senior bulls that averaged
1,205 lb. at the end of the test.
Since feed accounts for the majority of the expense in-
volved in beef production, it is extremely important that feed
efficiency, as well as rate of gain, be considered in selecting
bulls for commercial beef herds. Both of these traits are
highly heritable and therefore subject to improvement through
selection.
Auburn University Agricultural Experiment Station
a Real Este Market
Developments and Imphations
. . YEAGER Department of Agricultural Economics 
and Rural Sociology
I T TAmES a lot of money to get set up
in farming. The major reason is increas-
ing farm real estate values. There are
significant, implications of higher farm
real estate values to those who wish to
start farming, those presently owning and
operating farms, and to those contemplat-
ing the sale or transfer of a farm.
One has to go back to 1954 to find the
last year that the average value of farm
real estate per acre declined in the
United States, see chart. Economic data
available to the Agricultural Experiment:
Station show that for Alabama it was also
1954. However, the 1950's were gener-
ally a period of increasing farm real es-
tate values. The last time of declining
values for a period of years was in the
1930's.
But the period of most rapid increases,
based on the record of farm real estate
values, was the 1970's. Average annual
percentage increases were in the teens
with the highest of 23% for the United
States registered in 1974. In Alabama,
farm real estate values increased an aver-
age of 24% in 1974.
Since farm real estate is a major part
of the capital investment in a farm, total
capital investment has increased drasti-
cally in the past few years. USDA re-
ported the average total investment in
production assets per farm in 1978 as
$219,625, or $142,622 per farm worker.
This investment has more than doubled
since 1972. A major part of the increase
resulted from higher farm real estate
values.
For the farmer who is attempting to
get set up in farming, these higher values
have major implications. Unless the per-
son already owns farm real estate and has
some equity accumulated, it is most dif-
ficult to obtain financing. One of the
reasons is that farm earnings have not in-
creased in proportion to real estate values.
Consider this example. Suppose that
6 years ago a young farmer could have
bought a 400-acre farm for $300 per acre
or a total of $120,000. Assume that net
earnings from the farm would equal
about $20,000. In 1978, based on the
average increase in Alabama farm real
estate since 1972, this 400-acre farm
would have a price tag of about $573
per acre or a total of $229,200. Although
net farm income has fluctuated consider-
ably from year to year, as an average
there has not been a great change since
1972. Thus, if only farm income is con-
sidered in financing the farm and the
farmer bought the farm in 1978 rather
than 1972, the ratio of capital investment
required relative to income generated al-
most doubled. As a result of this situa-
tion there has been increased demand
for income from nonfarm sources to help
in the financing of farms. Many farmers
and members of their families have ob-
tained full or part-time jobs off the farm.
In some cases the increased farm real
estate values have gone beyond the abil-
ity of the productivity of the land to sup-
port the high level values at present farm
product prices. This is most pronounced
in areas where non-farm factors such as
urbanization are influencing values.
Farmers are not normally in the busi-
ness of buying and selling farm real es-
tate. Their objective is to generate net
income from use of the land resource in
farming. However, one way to capitalize
on the increasing farm land value is to
sell. The substantial increases in farm
real estate values in recent years have
invited non-farmers to invest in farm land
and to take advantage of the rising mar-
ket. There are tax advantages that may
accrue, in particular from capital gains
treatment of profits from the sale of 
farm
real estate.
The investment by foreign groups and
individuals in U.S. farmland has received
attention in recent weeks and months.
No doubt one of the reasons for such 
in-
vestments is to hedge against further in-
flation. Also, possible incentives may
exist for foreign investors.
1
To the farmer who invested in a farm
several years ago, the increasing annual
farm real estate values have meant the
building of equity or an estate. Of
course many farmers have used this in-
creasing equity to buy additional land
or expand operations. Records indicate
that more than 50% of the purchases of
farm real estate in recent years have been
for enlargement purposes. This in itself
has been a factor in increasing values be-
cause of the dollar amount a farmer is
willing to pay for small tracts conven-
iently located to his existing farm. The
increased price paid may be justified
based on gains in efficiency of operation
from increasing farm size.
A farmer who has built an estate of
considerable value through increased real
estate values or otherwise needs to make
wise decisions in utilization of this estate
for retirement purposes and inter-genera-
tion transfers.
Thus the implications of farm real es-
tate market developments depend on the
situation in which the farmer finds him-
self and 
his opportunities 
to take advan-
tage of the situation through wise man-
agement decisions.
Donald Abramson, Karl Gertel, and
James Lewis, "Federal Taxation of and In-
centives for Foreign Investment in U.S. Real
Estate," Proceedings of the Seminar on Fed-
eral Taxation and Land Use, Lincoln Insti-
tute of Land Policy, Cambridge, Massachu-
setts, April 9-11, 1978.
Percent of March I, 1967
4001 
m
1910 20 30 40 50 60 70 
80
Index of U. S. form real estate value per ocre
Auburn University Agricultural Experiment Station
J L TURNER, Department of Horticulture
I T Is THE GENERAL practice in Alabama
to grow potatoes in slightly acid soils,
because of the danger of potato scab'
when soil pH value is above about 5.7.
Because of a fear of overliming, commer-
cial potato growers have a tendency to
underlime their soils. With the wide-
spread use of acid-forming nitrogen fer-
tilizer, soil acidity progressively increases
with fertilizer use. This acidity effect can
readily be overcome by an adequate lim-
ing program. Without corrective liming,
soil acidity will develop to the point that
potato yields will be severely reduced.
During recent years, several liming ex-
periments by the Auburn University Ag-
ricultural Experiment Station have veri-
fied a need for liming highly acid potato
soils for commercial production. One of
the most important findings is that maxi-
mum yields are realized in the soil pH
range in which scab does not usually
occur.
At the Gulf Coast Substation, in Bald-
win County, an experiment was con-
ducted on a Malbis fine sandy loam soil
that had a soil pH range of 4.8 to 7.0.
The soil pH values in the graph are for
samples taken in winter prior to planting
potatoes. Open circles on the graph rep-
resent potato yields as affected by soil
pH at that location.
Maximum yield was realized at a soil
pH of 5.3. At higher pH values, yields
were about the same. No scab was ob-
served at the higher pH values. How-
ever, potatoes had not been grown on
this particular field before, and certified
seed were used.
Another experiment was established in
1975, this one on a Hartsells fine sandy
loam at the Sand Mountain Substation
in DeKalb County. This location also in-
cluded a range in soil pH values. Yields
at this location are represented by the
square points on the graph. Maximum
yield was realized at pH 5.(
83% of the maximum at pH
. Yield was
5.1 and only
Relative yield of potatoes as affected by soil pH.
55% of the maximum at pH 4.8. Raising
the pH to 6.5 at this location did not in-
crease yields over that at pH 5.6.
In 1974, lime experiments were begun
on growers' potato fields in the Sand
Mountain commercial potato producing
area of northeastern Alabama to better
define the soil pH requirements for po-
tatoes. Placing such tests on farmers'
fields, in addition to those on units of the
Experiment Station, provides results un-
der a variety of management practices on
different soil types. These experiments
cover a period of 5 years and are repre-
sented by the solid circles on the graph.
Results show that a soil pH of about 5.3
is the point of maximum yield and that
more acid soils sharply decrease yields.
Liming some of these fields to pH 5.7 or
higher resulted in potato scab disease.
s The effect of acid soils on potato yields
is deceptive, because plant symptoms
may not be obvious. For example, plants
growing side by side on a highly acid
plot and on a limed plot may look the
same in top growth. At harvest time, how-
ever, tuber yields will be less on the
low-pH plots. Root observations at the
Sand Mountain Substation about 6 weeks
after planting indicated major differences
in root growth as a result of soil pH dif-
ferences. At pH 5.6, there was an exten-
sive, well branched, healthy-looking, fi-
brous root system. At pH 4.8, there were
only a few thickened, poorly branched
roots. Even though plant tops grew about
the same during the season, the effect of
poor root growth was highly evident in
tuber yields at harvest time.
All these tests show the same results:
Maximum production can be realized
within the soil pH range of 5.2-5.7, a pH
range where scab does not occur. The
results showed definite benefits of liming
to correct high soil acidity caused by con-
tinuous use of fertilizers. However, there
was no additional benefit from liming to
pH values higher than 5.6, which would
bring soils into the danger zone for potato
scab.
Auburn University Agricultural Experiment Station
: Reo" tiveC -c K' 
+? I y
yield, pct .
OOh
0o - Oh AGulf 
Coast Substtio
O Sand Mountain Substation
SPotato Fields
40!
T",4* 909
4.7 4.9 51' 5.3 5.5 5.7 5.9 6A 6.3 6.5
Soil pH 11
~VU J UV V~VII rYII V UJ UI UUV~1LlULV ~YI1
C
X
LANDLORD-TENANT RELATIONSHIPS
SIDNEY C. BELL and BRUCE CANOLES
Department of Agricultural Economics and Rural Sociology
THE LAW defines a tenant as anyone
who uses the land of another and pays
rent either in cash, crops, or livestock.
The tenant with a written, long-term lease
is in an advantageous legal and economic
position. However, many tenants con-
tinue to occupy land on a short-term
agreement basis. Economic data avail-
able in the Agricultural Experiment Sta-
tion show that in Alabama a short-term
tenant is involved in one of three types
of tenancy. In each type the landlord,
as well as the tenant, is in different legal
positions with varying legal rights and
responsibilities in regard to continuation
of the lease arrangement.
Tenancy from Year to Year
The first type of tenancy is "tenancy
from year to year." Alabama law pro-
vides for the termination of lease agree-
ments on an annual basis (December 1
unless otherwise specified), if the lease
is an oral agreement or if rent is collected
annually or unless a longer lease period
is explicit and in writing. Therefore, any
tenant who does not have a long-term
written lease with a multi-year rental
payment agreement has a "tenancy from
year to year" leasing arrangement. The
"tenancy from year to year" was created
when the tenant made his oral agreement
with the landlord to rent the property for
the current year. -
In the case of a "tenancy from year to
year," the landlord has the right to re-
claim his property when the lease term
expires. However, the tenant is entitled
to some considerations, and when and
how the landlord repossesses his land are
restricted by law. The "tenant from year
to year" maintains all the possessory
rights to the property granted him in the
annual rental agreement for the full du-
ration of his lease term. Nonetheless, the
law clearly specifies that annual leases do
not automatically carry over to the next
year in the absence of a notice to termi-
nate. Therefore, since the landowner is
not obligated by law to give notice of his
intent not to renew the oral lease, it is
the responsibility of the renter to vacate
the premises of the landlord when his
current lease term expires. If the tenant
does not vacate the premises on his own,
the landlord may evict him. The land-
lord, however, must give the tenant
proper notice of his intentions and the
eviction notice may not be delivered until
after the tenant's annual lease term has
ended. After the lease has expired, the
landlord has two legal-eviction remedies
(unlawful detainer proceedings or eject-
ment) at his disposal to regain control of
his property from a "tenant from year to
year" who refuses to relinquish posses-
sion.
In a "tenancy from year to year" ar-
rangement, the landlord's legal right to
terminate the contract at the end of the
current lease term is all but undisputable.
Nevertheless, the tenant is protected by
statutes and court decisions from errors
by the landlord in interpreting the oral
contract and from any unreasonable or
unequitable demands of the landowner.
The second type of tenancy is a "ten-
ancy at will." A "tenancy at will" is
similar to "tenancy from year to year" in
that no fixed term is specified. Under a
"tenancy at will," however, a landlord or
tenant may terminate the lease by giving
the other party 10 days' written notice of
intent to vacate the premises.
Tenancy at Will
A "tenancy at will" may be created
implicitly if the tenant remains on the
lands of the landlord after the term of a
previous agreement has ended, and if the
landlord does not voice objection to the
arrangement. Under these conditions, the
tenancy may be allowed to continue for
an indefinite period, and often a "reason-
able notice" is required rather than the
customary 10 days' notice. Depending
on circumstances the reasonable notice
period may extend to 30 days, particu-
larly if extension of the agreement was
continued more or less on a monthly basis
and a period in excess of 10 days is nec-
essary for the tenant to vacate the prem-
ises. Although there is no security for
either party in a "tenancy at will," both
the landlord and the tenant have an equal
legal right to terminate the agreement.
However, in the event the landlord elects
to end the lease, and if after proper no-
tice the tenant refuses to leave the prop-
erty, then the landlord has available the
legal remedies of unlawful detainer and
ejectment.
Tenancy at Sufferance
The third type of tenancy is a "tenancy
at sufferance." Persons who acquire pos-
session of land or other real property 
by
some lawful means, such as an annual
lease, but who fail to leave the premises
after the term has expired and notice
given, create a "tenancy at sufferance."
There is a distinction between failure to
vacate the lands creating a "tenancy 
at
will" and one at sufferance. The "ten-
ancy at will" was created implicitly with
the approval of the landowner. A "ten-
ancy at sufferance" is automatic 
when a
tenant remains in control of the 
lands
without the landowner's consent. 
There-
fore a "tenant from year to year" 
upon
expiration of his lease term becomes either
a "tenant at will" or a "tenant at 
suffer-
ance," depending on the acquiescence 
of
the landlord. A "tenant at sufferance" 
is
legally entitled to very few considerations
by the landlord. About the only 
right
the landowner must allow the "'tenant at
sufferance" is sufficient time to complete
the job of moving.
None of the three types of short-term
tenancy offer the renter or the landowner
any certainty 
about the future 
of the
landlord-tenant relationship. One year is
not sufficient time to initiate farm im-
provement practices or justify acquisition
of expensive machinery. The uncertainty
of annual agreements reduces the incen-
tive of both parties for making fixed 
in-
vestments that may not be recovered for
several years, such as soil liming, building
fences and other needed improvement, or
various conservation practices.
Written Agreement Preferred
Another weakness of many Alabama
landlord-tenant agreements is that it is
an oral agreement. Oral leases for 1 year
or less are legal and binding, but 
the
written agreement is much preferred.
The act of condensing an oral agreement
to writing forces both landlords and ten-
ants to think-out more of the detail of
their agreement and reduces the possi-
bility of a misunderstanding later about
what the agreed terms were.
If the farm lease is chosen as a means
to farming or farm operation enlargement
it is definitely advantageous to have a
written long-term lease agreement. This
will provide better understanding be-
tween landlord and tenant and will con-
tribute to the longevity of successful
farm operations.
6Auburn University Agricultural Experiment Station6
TIHE EXTENDED TIME interval when pe-
can trees produce new leaves provides a
long susceptibility period for infection
and conidial development by Fusicladium
effusum, the causal fungus of pecan scab.
Pecan leaves are susceptible to scab
when they are immature and yellow-
green and become less susceptible as
they mature and turn dark green. During
this period, new scab lesions or leaf spots
develop when environmental conditions
are favorable. Leaf emergence along the
growing shoot and maturity of leaflets
along the leaf rachis prolongs the time
and amount of susceptible pecan leaves
available for scab development. An in-
creasing number of lesions develop on
each succession of leaflets during rainy or
highly humid weather.
Development of scab lesions on pecan
leaves was followed from April to the
first part of June at the Bedingfield pecan
orchard approximately 5 miles west of
Auburn. Twenty compound leaves were
collected by scientists of the Agricultural
Experiment Station at weekly intervals
per tree from four sectors around 12 ran-
domly-selected mature Schley trees. If
sufficiently mature, the second compound
leaf was collected 7 days after the first
leaf with similar procedures used for the
third and successive compound leaves
throughout the foliation period. Leaf
buds opened about March 20 on Schley
pecan with scab infection developing suf-
ficiently for lesion counts to be made by
mid-April. Lesion counts for each com-
pound leaflet pair were recorded for each
collection period.
The two-phase growth pattern of pe-
can foliage or the succession in leaf
emergence and development that pro-
longs the susceptibility periods for F.
effusum infection is illustrated in the
photograph. A series of leaves from one
representative pecan shoot were photo-
graphed during the first week of May.
SOME FACTORS INFLUENCING
PECAN SCAB DEVELOPMENT
A. J. LATHAM, Department of Botany and Microbiology.
Compound pecan leaves from the same shoot showing scab lesions (black spots) on matured
and maturing leaflets. Only the alternately formed 1, 3, 5, and 7 compound leaves are
illustrated.
Compound leaf 1 was mature, while the
three terminal leaflets of compound leaf
3 and 5 were immature. The leaflets of
compound leaf 7 were just beginning to
unfold. Some lesions were just visible
on maturing terminal leaflets of com-
pound leaves 3 and 5. Extensive leafspot
symptoms were evident on terminal leaf-
lets late in May and June, table 1.
The data indicated that new compound
leaves kept emerging along the elongat-
ing shoot to provide a continuous suc-
cession of susceptible leaf tissue. After
the second week of May, lesion numbers
increased very rapidly and, consequently,
inoculum (spore populations) was inten-
sified. These high-spore populations, ac-
TALE 1. NUmER OF ScAB LESIONs ACCORDING TO SAMPmNG DATE, LEAFLE
PAIR, OR TERMINAL LEAF DURING 1976
Corn- Maturity Leaflet pairs and average Terminal Total
Date pound 
of number 
of lesions leaflet 
lesionstalDalL d terminal lesions
leaf leaflets 1 2 3 4 5 6 lesions
No. Pat.
April 16. 1 -.. .. .- 1.4
April 23_ __ 1 55- -- . ... - -- - - - -7.3
April 302 73 . .. 7.7
May 7_ 3 84 2.0 2.2 2.3 1.7 2.1 0 1.2 11.5
May 14 ..... 4 89 1.4 1.4 1.4 1.5 3.9 1.0 2.7 12.5
May 21 _ 5 90 0.6 0.8 2.5 9.2 11.3 2.3 8.1 34.8
May 28 6 90 0.5 2.0 9.9 22.4 33.9 14.7 19.3 102.7
June 4' . 7 91 3.4 15.8 45.7 76.7 94.2 56.3 55.7 347.8
' Based on development of 3 terminal leaflets.
' Trees were fully leafed-out, a few new leaves emerged on terminal shoots throughout
the summer.
companied by wet weather and an abun-
dance of susceptible leaf tissue, resulted
in such high lesion numbers that count-
ing became difficult by June, table 2.
Scab was so severe during 1975 that de-
foliation occurred in July and new leaves
appeared in August. No nuts were set in
this orchard during 1976. This tends to
confirm reports by other researchers that
TABLE 2. AVERAGE NUMBER OF SCAB
LESIONs PER COMPOUND LEAF ON
SCHLEY PECAN ACCO DING TO
WEEK ANTD YEAR
Month and week 1975 1976
April 2 1.4
April 3 .- 7.3
April 4 36.2 7.7
May 1 69.3 11.5
May 2 40.5 12.5
May 3 285.8 34.8
May 4 238.0 102.7
June 1 800.0 347.8
pecan trees must retain their leaves well
into the fall to obtain a nut set the fol-
lowing year.
The susceptibility period of pecan fol-
iage may extend for 90 or more days dur-
ing leaf development. During this time,
protective fungicide applications made at
regular intervals are essential to (1) con-
trol inoculum buildup and (2) prevent
infection of the tender young pecan nut-
shucks.
Auburn University Agricultural Experiment Station
Pond Water Movement
Can Improve Natural Aeration
C. D. BUSCH and C. A. FLOOD, JR., Dept. of Agricultural Engineering
ON A SUNNY DAY the plant life. in a cat-
fish pond manufactures oxygen rapidly
enough to boost the pond water oxygen
concentration up to supersaturated levels.
It's not uncommon to measure 10-14
parts per million (p.p.m.) of oxygen even
though the saturation level is only 7 or 8
p.p.m. At least this is true in the top few
feet of pond water penetrated by sun-
light. Beneath the level of light penetra-
tion, if there's no top to bottom water
movement, the oxygen concentration may
be near zero p.p.m. Catfish cannot sur-
vive in water in which oxygen concentra-
tion has dropped below about 1.0 p.p.m.
Since oxygen depletion is the most
common cause of massive fish kills, it is
beneficial to maintain adequate levels of
dissolved oxygen in the deeper locations
of the pond. This allows for a more con-
tinuous oxidation of waste products and
increases the total reserve of oxygen
available in the pond.
Experiments at Auburn University's
Agricultural Experiment Station with
multiple paddlewheels, like those shown
in figure 1, have demonstrated their value
in mixing oxygen rich and oxygen poor
water. Six paddlewheels, powered by 1/4
hp. electric motors, were positioned to
provide circular water movement in a 1.4
acre pond as shown in figure 2. The pad-
dlewheels were controlled by time clocks
and set to run continuously for 5 hours.
Dissolved oxygen measurements were
made periodically to note any changes of
concentration.
The results for one set of measure-
DISSOLVED OXYGEN LEVELS AS INFLUENCED BY WATER MOVEMENT
(PARTs PER MILMON)
Time Deepest pond location Northwest comer
Depths
1' 5' 
10' 1' 
4' 8'
Midnigt.__ 8.5 8.3 2.7 8.5 8.2 3.8
Paddlewheels on 1:00-6:00 a.m.
:00 a.m......7.2 6.6 3.9 7.4 7.4 6.0
6:00 a.m . . -6.6 6.7 6.6 6.7 6.7 6.5
ments are shown in the accompanying
table. An hour before the paddlewheels
were started, a definite decrease in oxy-
gen level was evident for measurements
made in the deeper locations. After 2
hours of operation (3:00 a.m.) some im-
provement in oxygen level near the pond
bottom could be seen. After 5 hours of
stirring, the water had achieved a uni-
form oxygen content. This was true for
both the deepest location within the main
paddlewheel current, and the northwest
corner which was a good distance out-
side the flow circle. Decrease 
min oxygeA
levels at the surface is due to mixing,
oxygen use by fish waste and plants in
the pond, and the mechanical aerator's
removing oxygen from the water when
it is supersaturated. (In this case about
7.3 p.p.m.).
FIG. 2. Catfish pond with paddlewheel and
measurement location
FIG. 1. Paddlewheels in action.
Auburn University Agricultural Experiment Station
M D.O. meosement locations
M Poaddlew el locations
Surface area 1.4 acres
I _ _
GOOD FALL TOMATOES
WITH TRICKLE IRRIGATION
B. D. DOSS, Department of Agronomy and Soils, Coop. USDA-SEA
J. LI TURNER, Department of Horticulture
C. E. EVANS, Department of Agronomy and Soils
FALL-GROWN TOMATOES are not gener-
ally thought to be a good crop in Ala-
bama because of drought, high tempera-
tures, and disease and insect problems.
However, Alabama's late frost date allows
sufficient time for a fall crop if these ad-
verse conditions can be overcome.
Nothing can be done about heat, of
course, but irrigation can solve the
drought problem. Trickle irrigation re-
sulted in 
good production 
in 1978 re-
search by the Auburn University Agricul-
tural Experiment Station. Despite severe
drought, both yield and quality were
high when irrigation was combined with
strict disease and insect control measures.
Different nitrogen rates, number of ap-
plications, and methods of application
also were studied in the irrigation project
with Tropic variety of tomato. Nitrogen
rates compared were 40, 80, and 120 lb.
per acre - applied either dry or in the
irrigation water. The dry N material was
ammonium nitrate. That put out in irri-
gation water was a commercial solution
of equal amounts of urea and ammonium
nitrate containing 30% N.
For treatments getting two N applica-
tions, one-third was applied at planting
and the remainder when fruits on the first
hand were approximately 1 in. in diam-
eter. Plots getting eight N applications
received N at weekly intervals beginning
at planting.
Test plots were rototilled and chiseled
beneath the row to a depth of 12-15 in.
immediately before plants were set July
6. The P and K fertilization was based
on soil test. Weekly spraying with insec-
ticide and fungicide provided effective
pest control.
Water for the trickle irrigation system
was applied through a single line of twin-
wall plastic tubing placed on the soil sur-
face next to the plants. Liquid nitrogen
solutions were loaded into cylinders and
injected by compressed air into the irri-
gation lines through plastic quick-coup-
lers. Amounts were controlled according
to the individual row treatment.
Rainfall was unusually low during the
latter part of the 1978 fall crop period.
Total rainfall from planting to last har-
vest was 10.8 in. However, only 1.6 in.
of this fell during the 71-day period pre-
ceding last harvest.
Plants were irrigated approximately 5
to 6 days after rain and every 2 days
MARKETABLE TOMATO YIELDS AS AFFECTED BY IRRIGATION, NrrOGrEN RATE,
NUMBER OF N APPLICATIONS, AND N APPLICATION METHOD
Marketable yield/acre, by N rate/acre
Irrigation and nitrogen treatment 40 lb. 80 lb. 120 lb.
Lb. Lb. Lb.
No irrigation
Dry mix ammonium nitrate, 2 applications-.... - 20,460
Trickle irrigation
Dry mix ammonium nitrate, 2 applications ........ ..... 40,550
Liquid N in irrigation, 2 applications... 39,060 47,630 48,950
Liquid N in irrigation, 8 applications -.......... 44.020 49,690 50,490
Tomatoes were grown with and without ir-
rigation (left) and with three nitrogen rates
(right).
thereafter. About /4 in. of water was
applied at each irrigation. Number of ir-
rigations totaled 36 for the season, with
8.6 in. of water applied.
Early plant growth and plant height
at first harvest showed little difference
among treatments. Average final plant
heights ranged from 47 to 54 in. for the
different treatments shown in the table.
But there were tremendous differences in
yield among treatments, especially be-
tween irrigation and no irrigation, as
shown by data in the table.
Irrigation increased marketable yield
an average of 20,000 lb. 
per acre, nearly
double the production without irrigation.
At the 120-lb. N rate, marketable yields
ranged from 20,460 lb. per acre with soil
applied ammonium nitrate and no irri-
gation to 50,490 lb. with trickle irrigation
and weekly applications of liquid N.
Increasing N from 40 to 80 lb. per acre
boosted marketable tomato yield an aver-
age of 7,100 lb. A further N increase, to
120 lb., increased production another
1,060 lb. per acre.
Method of applying N also had an ef-
fect on production, as shown by results
with 120 lb. of N in two applications.
Applying it in irrigation water increased
yields by about 8,400 lb. per acre over
the same amount to the soil. Dividing
the N into 8 weekly applications in-
creased yields an average of 2,850 lb.
per acre over that for the two N applica-
tions (average of all rates).
Yields reported were obtained in har-
vests over a 4-week period, with the last
harvest on October 24. All marketable
size tomatoes were harvested October 24
in anticipation of a freeze. Neither a
freeze nor killing frost occurred as antici-
pated, however, and tomatoes continued
to produce and were harvested until De-
cember 5. Marketable yields would have
been considerably higher if harvesting for
yield records had been extended to De-
cember 5 in the normal manner.
In addition to boosting yield, irriga-
tion also increased the percentage of
large size fruit. An average of 71% of
fruit on irrigated plots was rated large, as
compared with 45% on nonirrigated plots.
There also were fewer cull tomatoes on
irrigated plots - 15% as compared with
34% with no irrigation.
These results indicate that high yields
of high quality tomatoes can be produced
in the fall by use of trickle irrigation and
adequate nitrogen.
Auburn University Agricultural Experiment Station
Cattle Egret Damage To Pine Plantations
JULIAN L. DUSI, Dept. of Zoology-Entomology
SINCE THE EARLY 1960's cattle egrets, large white birds
seen feeding in pastures with cattle, have come into Alabama
and become our most common wading bird. Their habit of
feeding on pasture insects, or following mechanized equip-
ment and feeding on soil insects and small animal life, have
all been quite beneficial; and cattle egrets are welcome in
most agricultural situations. However, when allowed to nest
in large numbers in pine plantations, they do damage trees.
An excellent example of this damage is in a pine plantation
adjacent to the Holiday Inn in Tuskegee in Macon County.
Egrets have nested there since 1970, but only since 1973,
when the nesting colony increased in size to about 12,000
birds, has the damage been so evident.
The birds have concentrated in an area about one-half acre
in size, shifting to different areas in the plantation after the
trees die. The figure (left) shows the destruction in the cen-
ter of the plantation; the trees already down and replaced by
undergrowth. The figure (right) shows the appearance of
the area, while the tree stubs were still standing. This is al-
most a complete loss as a pine plantation.
Though fecal droppings of the birds landing on leaves de-
foliate trees quickly, it is changes in the soil that are the most
significant.
Soil samples were taken in the colony area for several years
and control samples taken at the edge of the area, away from
the nesting birds and their droppings. The table shows the
soil sample data for 3 years. The samples vary but the
overall general tendency is the increase in pH and usually
greater increase in all of the nutrients. The pine trees were
growing well on the control soils. but then phosphorus was
increased 13 to 104 times, potassium increased four to 19
times, magnesium two to 12 times and calcium one and a
half to eight times. This was more than the pine trees could
tolerate and they quickly died.
Cattle egret colonies must be kept in areas where they are
compatible with man's activities. When they nest in pine
plantations, they should be immediately 
induced to move be-
fore they can cause damage. This doesn't mean for landown-
ers to kill the birds, because cattle egrets, like most other
birds, are carefully protected by State and Federal laws. In-
stead,. contact a Fish and Wildlife Service agent. In Ala-
bama, contact Keith McCartney, whose office is in Room 727,
of the Federal Building at 474 South Court Street, Montgom-
ery 36104. His phone number is 823-7228. Fish and Wild-
life agents can determine the legal and proper way of solving
cattle egret problems and help landowners to solve them.
In this way the cattle egrets can be carefully caused to
move from a place, where they will cause damage, to another
site nearby, where the benefits can be enjoyed.
Sore DATA FROM THE TUSKEGEE HERON COLONY SrrE
Phos- Potas- Mag- Calcium
Date Sample pH ph~orus sium nesiumCalcium
9-16-76 1 6.3 1,505 1,082 468 3,058
2 6.1 1,555 1,500 521 1,966
3 5.2 .690 772 115 650
Av. 5.9 1,250 1,118 368 1,891
Control 4.6 15 77 42 363
7-14-77 1 7.0 905 999 324 1,994
2 6.4 140 450 125 918
3 7.0 615 999 244 1,233
Av. 6.8 553 816 231 1,382
Control 6.4 28 113 60 529
8-28-78 1 6.3 440 427 144 810
2 6.0 256 359 64 250
Av. 6.15 348 393 104 530
Control 5.8 20 40 19 160
All nutrients expressed as pounds per acre.
Aerial view of Tuskegee Holiday Inn, the pine plantation remains to the left and the center of the pine plantation, devoid of trees.
Ground view of the center of the pine plantation, showing the dead trees.
Auburn University Agricultural Experiment Station10
AFLATOXIN B
1 
IS A potent carcinogenic mycotoxin produced
by the mold Aspergillus flavus on corn in the field and in
storage. In recent years, feed and livestock producers in the
southeastern United States have suffered from problems
caused by aflatoxin in corn. In 1977, 60% or more of the
corn grown in the South contained at least 20 ppb (jig/kg)
aflatoxin - the legal maximum level permitted by the Food
and Drug Administration for corn in interstate commerce.
Most methods for detection and analysis of aflatoxin in corn
are time consuming and expensive. The bright greenish-yel-
low fluorescence (BGYF) test has been used extensively for
rapid screening. Unfortunately, this test is highly contro-
versial and generally less reliable than most circumstances
demand. Minicolumn procedures are reliable but are also
expensive and time consuming. Minicolumn methodsrequire
10-15 minutes and cost approximately $1.00 per sample (sup-
plies only). Commercial laboratories charge $15.00 or more
per sample for aflatoxin analysis by minicolumn methods.
A new approach for detection and analysis of aflatoxin in
corn has recently been developed in the mycotoxin laboratory
at Auburn University Agricultural Experiment Station. It is
called the Fluorometric Iodine Rapid Screening (FL-IRS)
method. The FL-IRS method requires about 7-8 minutes and
costs about five cents per sample (supplies only). Samples
are designated aflatoxin positive or aflatoxin negative by this
test. Aflatoxin positive samples may be further analyzed by
one of the standard methods. No further analysis is required
for aflatoxin negative samples.
For analysis, corn samples are finely ground and 10 grams
of each sample of corn are stirred for 2 minutes with 25 ml
of extraction solvent (80% methyl alcohol-20% water). Fifty
ml of zinc acetate-salt solution is stirred into the mixture and
the sample is filtered under vacuum. The clear filtrate is
diluted with water to 100 ml. A check (control) is similarly
prepared using corn which is known to be free of aflatoxin.
One ml of a saturated aqueous solution of iodine is added
to a 20-ml aliquot of each clarified sample extract. A Cole-
man Model 12-C Electronic Photofluorometer, equipped with
special filters, is used for estimating the fluorescence of the
sample extracts containing aflatoxin. The instrument meter is
TABLE 1. SCREENING OF 170 CORN SAMPLES FOR AFLATOXIN
BY FL-IRS METHOD
1
Group No. of FL-RS Aflatoxin' Comment
Group samples screen ppbComment
neg./pos. 
ppb
I 119 negative 0 correctly labeled
II 32 positive 6-650 correctly labeled
III 14 positive 0 false positives
IV 5 negative 5,5,8,9,106 false negatives
Fluorometric iodine rapid screening procedure.
2
Determined separately by quantitative analysis by FL-I
method.
TAIE 2. Sc ENIN OF 170 ConN SAMPL.ES FOR
BGY FLUORESCENCE
Group No. of BGYF Aflatoxin Comment
Group samples neg./pos. ppb Comment
I 86 negative 0 correctly labeled
II 28 positive 8-560 correctly labeled
III 47 positive 0 false positives
IV 9 negative 5,6,9,10,10 false negatives
... 47,52,228,300
Screening Corn For Aflatoxin:
A New Approach
N. D. DAVIS and U. L. DIENER, Dept. of Botany and Microbiology
adjusted to zero using a water blank and to 50 using the clear
extract of the check (aflatoxin-free corn). Fluorescence of
samples is then determined by reading the meter of the in-
strument. Samples with meter readings of 54 to 100 are
labeled aflatoxin positive and samples with meter readings of
0 to 53 are labeled aflatoxin negative.
Table 1 lists the results of screening 170 randomly selected
samples of corn by the FL-IRS method. Actual aflatoxin con-
tent as determined separately for each sample by quantitative
analysis is also listed in table 1. Table 2 presents results of
the BGYF test on the same group of 170 samples (50 corn
varieties grown in 1978 at five widely scattered locations in
Alabama).
Results (table 1) show that only one sample containing
more than 20 ppb aflatoxin passed through the FL-IRS screen
compared with four (table 2) that passed through the BGYF
screen. Moreover,-the BGYF screen falsely labeled 47 sam-
ples as contaminated compared with only 14 false positives
via the FL-IRS screen. The false positives do not represent
a health hazard, since they do not actually contain aflatoxin
and in any event would not be consumed without further anal-
ysis. However, they are of importance since the follow-up
quantitative analysis is both time consuming and expensive.
Results also show that the FL-IRS test incorrectly labeled five
samples as false negatives. However, only one of the false
negatives contained more than 20 ppb of aflatoxin. False
negative samples are important since they contain aflatoxin
but are labeled aflatoxin negative. By comparison, the BGYF
test incorrectly labeled nine samples as false negatives, of
which four contained more than 20 ppb aflatoxin.
These results show that the new FL-IRS screening method
for aflatoxin in corn is more accurate than the BGYF test.
Other than capital outlay, the two screening methods would
require about the same time and expense for sample analysis.
Overhead and labor would be similar for both methods. Since
the BGYF test is controversial, the FL-IRS method appears
to be a valuable new screening method for aflatoxin in corn.
Auburn University Agricultural Experiment Station
Also known as the black light test.
Determined separately by quantitative analysis by FL-I
method.
11
Southernpea Pod Toughness
Appears Related to
Resistance to Curculio
KENNETH S. RYMAL and OYETTE L. CHAMBLISS
Department of Horticulture
S OME SOUTHERNPEA VARIETIES consistently sustain less dam-
age from the cowpea curculio than others growing next to
them in the same field. Such variety resistance to the crop's
major insect enemy could be valuable to growers.
Incorporating resistance into varieties has been difficult be-
cause of the lack of understanding of the mechanism of resis-
tance. Two Auburn University Agricultural Experiment Sta-
tion projects shed some light on the question. Both were re-
ported in Highlights.
The first
x 
indicated that resistance to curculio attack was
due in part to the lack of a feeding stimulant in the pods
which made them less attractive to the insects. In the second
project
2
, microscopic examination of pod cell structure showed
basic differences between resistant and susceptible cultivars
in the cell walls of the fiber layer of pods. This observation
led to the conclusion that these differences might contribute
to differences in pod strength or toughness. Pod toughness
that discourages penetration of the pod by insects might
therefore be a factor in plant resistance, along with the chem-
ical factor.
The latest Auburn study dealing with the question mea-
sured differences in pod toughness. A specialized laboratory
machine (Instron Model 1122 Food Testing System fitted with
a small stainless steel probe 1 mm in diameter) was used for
testing the pods.
After seeds were removed, the fresh pods were stretched
over a polyurethane block and hand held while the probe
penetrated the pods at the points which had covered the
'RYtAL, K. S. AND O. L. CHAMBLISS. 1975. Insect Resistant
Southernpeas May Lack Chemical Attractants. Highlights, Vol. 22,
No. 1.
2 EN.NIs, T. H. AND O. L. CHAMBLISS. 1976. 
Pods Resist In-
sect Penetration in Curculio Resistant Southernpeas. Highlights,
Vol. 23, No. 1.
Toughness of southernpee pods was measured by specialized lab-
oratory machine (left), which measured force necessary to pene-
trate the pod with a stainless steel probe (right).
center of each seed. Pods were selected from two curculio
resistant breeding lines (Ala 963.8 and CR 22-2-21) and one
curculio susceptible variety (California Blackeye). Pods rep-
resenting seven stages of maturity were tested.
In the three immature stages there was no obvious correla-
tion of curculio resistance with pod strength, as shown by
data in the table. In fact, at the immature stage, pods of the
susceptible California Blackeye were at least as resistant to
pod puncture as pods of the resistant lines. As the pods ma-
tured, however, the force necessary to puncture the resistant
pods became significantly higher than in the susceptible culti-
var. This is important since curculio feeding is much more
active on the mature pods, especially on those in mature I
and II stages.
Though all the pods were ranked subjectively by size, seed.
maturity, and color into seven maturity groups, there were
essentially only two maturity stages on the basis of pod
strength. Analysis of data for all lines and varieties tested
showed no differences among the three early stages or the
four later stages.
Analysis of data from all stages showed (1) there were no
significant differences in force values between the two lines,
and (2) the two resistant lines required significantly more
force to penetrate the pods than was true for the susceptible
variety.
Obviously, mature pods of curculio resistant southernpeas
are harder and more difficult to penetrate than those of va-
rieties that are susceptible to curculio attack.
FORCE REQUIRED TO PUNCTURE PODS OF TmEE SorrLHERNPEA
CULTIvARS AT TmHREE MATURMTY STAGES
Grams of force to puncture pods"
Maturity stage Caforna 
CR 22-2-21 Ala 963.8
Blackeye
Immature . 65a 50b 58ab
Immature 
.. lab 
54a 66b
Snap..-..--- 64a 72b 60a
Mature ..... 
52a 138b 
104c
Mature .... 
96a 136b 
126b
Color ._. 109a 126b 143c
Dry .........---------..------ 76a 125b 176c
Means followed by the same letter are not significantly dif-
ferent at the 5% level, within maturity groups.
Auburn University Agricultural Experiment Station
12
THERES NO QUESTION 
that creep feeding boosts 
weaning
weight of beef calves. But that does not necessarily mean
that nursing calves should get creep feed. Such factors as
quantity, quality, and distribution 
of forage, milking ability 
--06
of cows, calving season, and price of feed in relation to an-
ticipated calf prices are points that must be considered.
Several creep feeding experiments have been conducted at
the Black Belt Substation in earlier years using Hereford and
crossbred cattle. In a newer 5-year experiment by the Au-
burn University Agricultural Experiment Station at the same
location, creep feeding was evaluated with calves from Here-
ford cows sired by Hereford, Charolais, and Simmental bulls.
The test cattle were on dallisgrass-white clover pasture, 1%
acres per cow-calf unit. Grass hay and supplement were fed
to cows in winter. Calves were born from November to mid-
January and weaned 
August to October. 
All weaning weights
were converted to 270-day figures.
Cows and nursing calves were equally divided into three
groups,. based on breed of calf. A control group (group 1)
received no creep feed. The other two groups were creep
fed: group 2 received a high protein (19%), low energy ;
feed; and group 3 was fed whole shelled corn, a low protein, A
high energy feed. 
j - J!
Consumption of creep feed averaged 671 lb. per calf per
year for the high protein group and 716 lb. for those fed low
protein feed. It required 9.68 lb. of high protein and 10.71 A
lb. of low protein creep feed to put on an extra 
pound of gain [
over the control. During the 112-day winter period when 71
calves were small, 5.59 lb. of high protein and 5.31 lb. of low 1-
protein creep feed were required for an extra pound of gain.
Weaning weights of all breeds were heavier in groups 2
and 3 than in group 1, table 1. There was no significant dif-
ference between the two rations (groups 2 and 3) in weaning
weights. Steers and heifers showed the same type response
to creep feeding.
Steers and heifers getting 
creep feed also weaned 
with
~ithigher live slaughter 
grades, table 1. Group 3 steers graded
W eanig w slightly higher than group 2 steers, 
and group 3 heifers had
F'eeeifefreatmented ehigher grades than those in group 2. However, these dif-
* -ferences 
were too small to draw any definite conclusions.
( )With both creep treatments, Charolais and Simmental sired
fsteer and heifer calves were 
significantly heavier at weaning
i 
- 0 than Hereford sired 
calves, table 2. There were no significant
L e rdifferences between Charolais and Simmental calves. Even
uthough 
there were only minor differences 
in live slaughter
ogrades, Hereford calves had more backfat than other breeds
Sand low protein groups had more back fat than controls.
& Di CResults 
of the recent creep feeding study show 
that calves
CREwP Fxm TEST~ ~AVxE.,Oi C1HEE rErT S getting either high or low protein creep feed wean heavier
Bd Lethan non-creeped calves. Differences in the rations did not
groups averaged 63 lb. heavier than non-creeped calves of
L . ethe same breed. With Charolais and Simmental crosses, the
eeor_ 5.54 10.8 10difference was 64 lb. per calf in favor of creep feeding.
Charolais Heeford...... 574 1 612 106- 10 Although all breeds responded about the same to creep
Si. ..ental x Hereford .555 617 10.0 10.2 feeding, between-breed differences were noted. Charolais and
S10 =middle Cood, 11 - high Good '. Simmental sired calves averaged 55 lb. heavier than Hereford
: :.a: :.z * -: : " s___ sired calves under each feeding treatment.
Auburn University Agricultural Experiment Station 13
IS CULTIVATION NECESSARY for COTTON?
G. A. BUCHANAN, A. E. HILTBOLD, and J. E. STREET
Department of Agronomy and Soils
FROM THE BEGINNING of row crop agri-
culture, farmers have pulled weeds by
hand, hoed them out of the soil, uprooted
and buried them with cultivators drawn
by animals and later by tractors, and
most recently killed them with herbi-
cides. Some chemical weed control prac-
tices are so effective that little if any cul-
tivation is needed for weed control in
crops such as cotton. If weeds are not a
competitive factor for cotton growth, can
cultivation be eliminated without losing
yield? Research shows that it can.
Effects of shallow cultivation, deep
cultivation, removal of weeds without
stirring the soil, and allowing weeds to
compete with cotton were determined in
experiments at the Tennessee Valley and
Sand Mountain substations of the Agri-
cultural Experiment Station on Decatur
silty clay loam and Hartsells fine sandy
loam soils, respectively. Experimental
areas were essentially level and were
plowed to about 
9 in. depth with 
a mold-
board plow in late winter each year. One
and sometimes two diskings were made
during seedbed preparation. Stoneville
213 cotton was planted with conventional
4-row planters in 42-in. rows each year
on the same plots. Fertilization, disease,
and insect control practices were applied
as necessary to remove these factors as
yield limitations. Cultivation treatments
began early in the season and consisted
of (a) flatweeding or cutting weeds at
the soil surface with a sharp hoe without
stirring the soil, (b) three shallow cul-
tivations, (c) three deep cultivations, and
(d) no weed control. Shallow cultivations
were made with tractor-mounted sweeps
set fiat to run 2 to 3 in. below the soil
surface, while deep cultivations were
made with the same equipment set to
run 4 to 6 in. deep. Weeds in the row
not removed by cultivation were hoed as
necessary to prevent competition. Herbi-
cides were not used in any of these treat-
ments. The flatweeding treatment simu-
lated a herbicide effect without tillage.
In each of 5 years at Tennessee Valley,
good yields of cotton were obtained
where weeds were removed, but essenti-
ally no yield obtained where weeds were
uncontrolled, see table. The equal re-
sults of shallow and deep cultivation and
weed removal without stirring show no
beneficial effects of cultivation beyond
weed control. Similar results were ob-
tained in 2 of 3 years at Sand Mountain.
Elimination of weed competition was the
critical factor for high yielding cotton; ex-
cept for 1969, no advantage was .gained
with cultivation. In this year, cotton yield
was increased by deep cultivation as
compared with flatweeding. A similar
trend occurred in 1970, but variability
indicated that the cultivation effect was
probably not significant in 1970. Other
tillage experiments on this soil show cul-
tivation increases rainfall infiltration and
improves corn yield. With cotton, how-
ever, this apparently is not a major fac-
tor. Differences in the nature of the root
systems of cotton and corn, as well as
differences in water requirements, may
account for their relative responses to
cultivation. While cultivation was gen-
erally no advantage to cotton, neither was
it detrimental. Root pruning by deep or
late cultivation has been implicated in in-
jury of corn and soybeans. For cotton,
the primary requirement is weed control
with effective and economical use of her-
bicides, cultivation, or combination of
both.
YIELD OF SEED COTTON AS INFLUENCED BY CULTIVATION
Treatment Seed cotton yield per acre
Treatment1969 
1970 1971 1972 
1973
Lb. Lb. Lb. Lb. Lb.
Tennessee Valley Substation, Decatur sicl.
Flatweed. ... .......... 2,174 2,724 4,454 3,259 2,677
Cultivate shallow (3 times)...... 2,097 2,647 4,183 3,360 2,895
Cultivate deep (3 times)--- 2,265 2,685 4,397 3,127 2,740
No weed control 220 40 20 0 864
Sand Mountain Substation, Hartsells fsl.
Flatweed 3 ,053 
2,950 3,419
Cultivate shallow (8 times)--- 3,272 2,984 3,128 ..... ...
Cultivate deep (3 times) . 3,395 3,347 2,989 ----- .
No weed control -- 153 278 5 ... ...
Auburn University Agricultural Experiment Station14
FARMERS ARE CONFRONTED with many
problems when trying to market products
effectively. Price uncertainty is a major
risk that has traditionally plagued farm-
ers.
Historically, the farmer's price was as-
sured only after transferring ownership in
the marketplace. Unstable and volatile
input and farm commodity prices, infla-
tion, international developments, techni-
cal advances, various government farm
policies, and seasonal weather conditions
are some of the factors which have added
to uncertainty in farm production and
marketing. In addition to this uncertain
environment is the fact that a majority
of the markets utilized by farmers have
market power concentrated on the side
opposite them.
Farmers are still basically "price
takers." However, shifts in institutional
arrangements in markets in recent dec-
ades have provided them more alterna-
tives. Thus, some flexibility as to market-
ing and pricing strategies employed by
farmers does exist, enabling them to bet-
ter their economic position through effec-
tive marketing planning.
Agriculture has experienced a large in-
crease in the number and types of coordi-
nated activities, ranging from complete
vertical integration to various forms of
contractual relationships. Through re-
search conducted at Auburn University's
Agricultural Experiment Station, attempts
are being made to identify the nature
and structure of farm-level markets for
major agricultural crops in the State, and
also to determine the extent to which
farmers are utilizing alternative market-
ing and pricing strategies to improve
their economic position and reduce price
risks.
REDUCING PRICE RISKS FOR
PRODUCERS OF AGRICULTURAL CROPS
J. L. ADRIAN, J. LOTT, and MORRIS WHITE
Department of Agricultural Economics and Rural Sociology
Information obtained revealed that al-
ternative marketing opportunities were
available for soybean, cotton, peanut,
and corn producers. For various reasons,
however, individual producers restricted
the number of alternatives used. Peanut
producers had the most options with an
average of almost three potential buyers
available, see table. Cotton farmers had
the fewest selling alternatives. Twenty-
nine percent of the cotton producers
knew of only one market outlet, and 92%
sold to only one buyer. Other commodity
producers seemed to be fairly loyal to
one marketing firm in that 60% or more
of the producers sold to one outlet.
Prices, convenience, and tradition were
reasons most commonly offered to explain
this relationship.
Cooperative organizations were found
to be important in marketing soybeans,
peanuts, and corn. One-half of the soy-
beans and about one-third of the peanuts
and corn were sold through these outlets.
Cooperatives act to gain market power
for their members; that is, they attempt
to increase competition in the market and
thus increase economic benefits to mem-
bers through higher prices and income.
Higher than average prices received at
cooperative outlets indicated that they
were achieving their goals and were vi-
able alternatives. In fact, the differences
MARrriNrc PRACTICES AND STRATEcmS OF CROP PRODUCERS,
BY MAJOR CROPs, ALABAMA, 1977 CROP YEAR
Item Unit Major crops
Soybeans Cotton Peanuts Corn*
Marketing practices:
Potential buyers identified by seller. no. 2.5 1.7 2.7 2.3
Sellers knew of only one buyer .- pet. 13 29 6 17
Buyers utilized no. 1.5 1.1 1.5 1.4
Sold to only one buyer. pct. 62 92 80 65
Used cooperative outlet. _ ______ pect. 60 6 34 33
Price received-all dol. 6.26 .50 402 2.20
Price received---cooperatives dol. 6.33 407 2.38
Marketing strategies:
Harvest and sell. pet. 37 39 96 71
Sell part at harvest and store rest .. pet. 29 38 20
Contract agreement pet. 33 13 5
Use of govt. loan program pct. - 6 - -
Other-...._pct. 1 4 4 4
Hedged---- pct. 1 4 0 0
* The 1977 corn crop year was abnormal in that weather and aflatoxin influenced pro-
duction and marketing.
** Too few observations were available to make comparisons.
in prices could result in substantially
higher incomes for producers marketing
large volumes through these outlets.
Alternative marketing and pricing stra-
tegies for soybean, cotton, and corn pro-
ducers were not used extensively to cope
with risks. Over one-third of the soybean
and cotton producers and almost three-
fourths of the corn producers sold their
output at harvest. Another 29% of the
soybean producers, 38% of the cotton
producers, and 20% of the corn producers
sold part of their output at harvest and
stored the remainder hoping for higher
prices. The government loan program
was utilized by 6% of the cotton pro-
ducers. Marketing peanuts differed from
marketing of other commodities in that
government policy influenced pricing and
marketing in a way that resulted in less
need for farmers to utilize alternatives.
One-third of the soybean producers
and 13% of the cotton producers used
contracts in which price and other mar-
keting terms were stipulated. These var-
ied from forward contracting arrange-
ments, which were most prevalent, to
deferred pricing arrangements. Hedging
in the futures market was not a common
practice among Alabama farmers.
In summary, Alabama farmers have al-
ternatives available in marketing and
pricing products. Basically, they continue
to sell products at harvest, but storage,
contracting, and hedging are being used
to prevent drastically low prices at har-
vest and to reduce extreme price variabil-
ity. Several reasons for the lack of more
extensive use of alternative practices were
reported. First, farmers lacked the nec-
essary information to initiate these ac-
tions. Second, bad experiences may have
been detrimental to continued use of the
alternatives. Use of practices that re-
duced losses resulting from price declines
also limited potential gains in the case of
price increases. Some farmers prefer to
assume risks and accept gains and/or
losses that result. Farm commodity prices
are moving on an upward trend. At
higher levels of prices, opportunities for
wide price fluctuations are greater and
use of practical pricing alternatives will
grow in importance to farmers.
Auburn University Agricultural Experiment Station 15
erous inquiries as to the identity, life cy-
rE
\
Life Cycle
The tent caterpillar spends the winter
in the egg stage. Eggs occur in masses
'- , in the form of bands encircling twigs of
host trees, figure 2. Hatch occurs in
spring about the time that leaf buds of
host trees begin to unfold. In the Au-
burn area, hatch began about March 1
in 1977 and on March 13 in 1978. Time
of hatch may be 10 days to 2 weeks
earlier in southern Alabama and delayed
by this time period in northern Alabama.
IG. 1. Eastern tent caterpillar in cherry.
THE EASTERN TENT CATERPILLAR
L. L. HYCHE, Department of Zoology-Entomology
D URING MARCH and April in Alabama,
large white silken webs are often evident
on trees scattered throughout the coun-
tryside, figure 1. A closer look will usu-
ally reveal that the webs are primarily on
wild cherry.
These webs, or tents, are made by lar-
vae of the eastern tent caterpillar, Mala-
cosoma americanum. In most years nat-
ural regulating factors keep populations
relatively low - a single web, occurring
on an occasional tree - and presence of
the caterpillar attracts little attention.
Periodically, however, populations may
increase so that: multiple webbing may
occur on most cherry trees; trees may be
completely defoliated; plants other than
wild cherry may be fed upon; and mi-
grating caterpillars become very notice-
able. Such a population increase occurred
in Alabama in 1977 and 1978 causing
considerable concern and prompting num-
e 0
Eastern tent caterpillar larvae are gre-
garious. Newly hatched caterpillars feed
briefly on the egg mass covering, figure
3, and begin construction of the web in
a limb crotch or crotch of trunk and limb
and enlarge it as they grow. Caterpillars
migrate from the web to feed and return
to the web where they remain between
feeding periods. Duration of the larval
developmental period is 5 to 6 weeks.
The fully grown caterpillar, figure 4,
is about 2 in. long. The body is dark,
sparsely clothed with fine, light-brown
hairs, and has a conspicuous light stripe
along the mid-line of the back. At this
stage of development, larvae abandon
their gregarious habit, leave the web, and
begin migrating in search of pupation
sites. It is during this period that cater-
pillars are often observed on non-host
plants.
Pupation occurs in white, silken co-
coons, figure 5, on the bark of trees, on
weeds and brush, under logs, leaves, or
other debris, on fences, and even on sides
of buildings. After about 
3 weeks, moths,
figure 6, emerge and begin laying eggs
in masses around twigs. In the Auburn
area, egg laying began on May 5 in 1977
and May 16 in 1978 and extended over
a period of 2-3 weeks. The number of
eggs per mass ranged 
from 212 to 424,
with an average of 287. Eggs remain on
the twigs through summer, fall, and win-
ter and hatch the following spring; thus,
there is only one eastern tent caterpillar
generation per year.
Egg production in 1978 was high.
Overwintering masses are currently abun-
dant on cherry trees, indicating the pos-
sibility of a high caterpillar population
again in 1979 unless natural control
agents, such as parasites and predators,
bring about a reduction.
Hosts and Damage
The favored host of eastern tent cater-
pillar in Alabama is the common wild
black cherry. When populations are at a
low level, oviposition and infestations are
confined primarily to this species, but
may also occur on apple. As populations
increase other plants of the Rose family,
including peach, pear, and plum, serve
as hosts for the caterpillar.
The eastern tent caterpillar, even in
periods of high population, is largely a
nuisance pest. Complete defoliation of
wild cherry trees may occur, but these
trees generally refoliate and little or no
economic injury results. However, de-
foliation of ornamental or fruit-producing
trees may cause sufficient damage to war-
rant application of measures for cater-
pillar control.
0 0
a4vi
?eeomna ,eio i i: 5 !6we
FIG. 2-6. Development stages of the tent caterpillar: (2) egg mass; (3) newly hatched caterpillars; (4)fully grown caterpillar; (5) silken
pupal cocoon; and (6) moth adult. Photos by J. V. rEdelson.
Auburn University Agricultural Experiment Station
F
16
Tm SOYBEAN cyst nematode, Hetero-
dera glycines, causes a destructive disease
in soybean referred to as "Yellow Dwarf."
This disease was first reported in 1915
in Japan. Other foreign countries where
the cyst nematode is known to occur
include Korea, China, Egypt, Poland,
and Taiwan. The first report of the soy-
bean cyst nematode in the United States
was in North Carolina in 1955. Since first
reported, this dreaded pest has .spread
rapidly throughout the eastern United
States.
The cyst nematode was first detected
in Alabama in the summer of 1973.
Shortly thereafter, a quarantine was
placed on portions of Conecuh, Escam-
bia, and Monroe counties in South-Cen-
THE SOYBEAN CYST NEMATODE:
A New Threat to Alabama Soybeans
F. A. GRAY, Pest Management Group, Ala. Cooperative Extension Service
R. RODRIGUEZ-KABANA, Dept. of Botany and Microbiology
FIG. 1. Distribution of the cyst nematode
in Alabama. Block areas indicate counties
where one or more fields were found to be
infested with cyst nematode. Blue coun-
ties moay have the soybean cyst nematode,
but it has not yet been detected.
FIG. 2. Partial stand loss caused by the cyst
nematode to soybeans in Jackson County.
tral Alabama. This action, taken by the
State Department of Agriculture, was im-
plemented in hopes of preventing the
spread of cyst nematodes to other soy-
bean growing areas of the State.
In July 1977, several soybean 
fields in
Northern Alabama, quite removed from
the area under quarantine, were found to
be severely damaged by the cyst nema-
tode.
Cyst Survey
To determine the extent of spread of
this pest within the soybean growing
areas of the State, a survey was con-
ducted beginning August, 1977 and end-
ing August, 1978. The survey was jointly
conducted by the Alabama Cooperative
Extension Service and the Alabama De-
partment of Agriculture. Soil samples
were collected from soybean fields with
a history of poor growth and from fields
that had a soybean cyst problem. Sam-
ples were tested in the Alabama Coopera-
tive Extension Service's Plant Diagnostic
Lab.
Of 335 soybean fields surveyed during
the one year period, 75 (representing 24
of the 67 counties) were found to be in-
fested with the cyst nematode, figure 1.
These 24 counties encompass over 65%
of the State's total soybean acreage. Soil
populations of the cyst nematode in some
samples exceeded 9,000 larvae per pint
of soil.
When laboratory records were checked
for 1975 through 1977, the number of
samples having cyst nematodes increased
from 2.1% in 1975, to 6.5% in 1976, to
22.4% in 1977, indicating a drastic in-
crease in occurrence of this pest within
the State.
Cyst Nematode Symptoms
Plant symptoms directly attributable to
the cyst nematode were first noticed in
early June and persisted until harvest.
Overall symptoms of infested soybean
fields usually consisted of stunted, chlo-
rotic, and dying plants occurring in some-
what circular areas from a few feet to
several hundred feet in diameter, figure
2. In addition, the incidence of several
fungal diseases including Southern Blight,
Pod and Stem Blight, and Brown Spot
appeared to be much higher on plants
having cyst nematode infections.
Crop losses were more severe in fields
where soybeans were continuously
cropped for several years. Yield losses in
individual fields were as high as 75%.
New Cyst Race
To complicate matters, four patho-
genic races of the soybean cyst nematode
have been described from the U.S. Races
are identified by their ability to repro-
duce on certain soybean varieties and/or
breeding lines. Since observations within
the State indicated that race 3 resistant
varieties were performing well, it was
assumed that race 3 was the dominant
population of cyst nematodes occurring
in Alabama. However, with the adjoin-
ing states of Tennessee and Mississippi
reporting the existence of the newly
formed race 4, the possibility of its de-
velopment in Alabama seemed likely.
This would be of particular interest since
soybean varieties having resistance to
race 4 are not yet available.
To date, greenhouse 
tests conducted
by the Agricultural Experiment Station at
Auburn indicate race 3 to be the domi-
nant race in Alabama. Should race 4 de-
velop, however, growers would be forced
to rotate out of soybeans for two or more
years or resort to chemical control, which
is relatively expensive.
Auburn University Agricultural Experiment Station
17
Use of Planting Time Application of Ethylene Dibromide
For Control of Plant Parasitic Nematodes on Soybeans:
New Uses For an Old Fumigant
R. RODRIGUEZ-KABANA, P. S. KING, H. W. PENICK, Dept. of Botany and Microbiology
F. A. GRAY, Pest Management Group, Ala. Cooperative Extension Service
E. L. CARDEN, R. N. McDANIEL, F. B. SELMAN, Gulf Coast Substation
HENRY IVEY, Wiregrass Substation
R ECENT ACTIONS by the Environmental
Protection Agency (EPA) have restricted
use of DBCP (Fumazone, Nemagon) on
soybeans to a degree that it can no longer
be considered for practical use on the
crop. In the past DBCP provided an in-
expensive (6-8 dollars per acre) means
of controlling nematodes parasitic of soy-
beans. While other nematicides can be
used for this purpose, they are either not
cleared for commercial use, or they are
too expensive because of the amounts or
equipment required to attain effective
control.
Ethylene dibromide (EDB) is one 
of
the oldest nematicides available for com-
mercial use. In the past its use on soy-
beans was not explored, probably 
because
of the general availability of DBCP and
early reports on other crops that the lat-
ter nematicide was two to three times
more effective than EDB. Since ED)B 
is
produced at comparable costs to DBCP,
it was thought that EDB could be an ade-
quate economical substitute for DBCP
for farmers to use on soybeans. This ar-
ticle presents results of experiments con-
ducted by Auburn University Agricultural
Experiment Station scientists during the
1978 season to determine the feasibility
of using a formulation of EDB (Soil-
brom? 90 EC) and a mixture of EDB
with 27% (w/w) chloropicrin (Terr-O-
Cide@ 72-27) at planting time for control
of nematodes parasitic of soybeans.
Tests were conducted at three loca-
tions in the State: (1) The Gulf Coast
Substation in Fairhope on a field heavily
infested with the root knot nematode
Meloidogyne arenaria; (2) in a field
heavily infested with race 3 of the soy-
bean cyst nematode (Heterodera gly-
cines), located on the Engel Farm in the
vicinity of Summerdale also in Baldwin
County; (3) in a field on the Wiregrass
Substation in Headland in Henry County
which was moderately infested with the
northern root-knot nematode (M. hapla).
The fumigants were applied at rates of
1.0, 1.5, 2.0, 2.5, 3.0, and 4.0 gal./
acre using two chisels per row sep-
arated 10 inches apart. A treatment of
1 gal./acre of DBCP 86 EC (Fumazone
86 EC) and no treatment control were
also included for comparative purposes.
In every test each treatment was repre-
sented by eight replications arranged in
a randomized complete block design.
Each replication was a single plot, two
rows (36" or 38") wide and 
20 ft. long.
The test at Fairhope did not include any
Terr-O-Cide 72-27 treatments.
Yield increases in the test at the Gulf
Coast Substation (table 1) in response to
applications of Soilbrom 90 EC were
sharpest in the range of 1.0 to 2.0 gal./
acre. Small but significant yield gains
over those obtained with the 2.0 gal./
acre treatment were evidenced with the
use of either 3.0 or 4.0 gal./acre of the
fumigant. Yield differences between the
1 gal. rate of Soilbrom 90 EC and the
DBCP 86 EC treatment were not signifi-
cant. The use of Bragg soybeans, a va-
riety with some 
degree of tolerance 
to
root-knot nematodes should have resulted
in higher yields for the control. However,
previous work has shown that tolerance
as measured by yield response is limited
and that significant yield increases can be
obtained by the use of nematicide treat-
ments in heavily infested fields such as
at the Gulf Coast Substation, even when
TABLE 1. EFFECT OF ETHYLENE DIBROMIDE (SonLROM 90 EC) AND A MxTURE OF
ETHYLENE DIBROMIDE CONTAINING 27 % CHLOROPICIN (TERR-O-CIDE 72-27) ON
YIELD OF BRAcc (GULF.. COAST) AND RANSOM (SUMMERDALE AND WIREGRASS)
SOYBEANS IN FIELDS INFESTED WTH THmmE DIFFERENT SPECIES OF
PLANT PARASITICm NEMATODES
Location
Gallons Gulf Coast Summerdale Wiregrass
Treatment per
acre Bu./acre Return Bu.acreReturn Bu./acre Return
Soilbrom 90 EC- .--- 1.5 26.2 51.5 9.9 14.5 47.9 82.5
Soilbrom 90 EC..... 2.0 36.3 96.0 12.1 19.5 44.1 57.5
Soilbrom 90 EC.2.5 37.9 98.0 14.6 26.0 44.9 55.5
Soilbrom 90 EC ... 3.0 40.0 102.5 15.2 23.0 44.8 49.0
Soilbrom 90 EC- ..-. 4.0 43.2 106.5 19.3 31.5 46.7 46.5
Terr-O-Cide 72-27 ..... 1.0 ... 6.9 3.5 32.8 11.0
Terr-O-Cide 72-27 - 1.5 .. 6.6 -5.0 48.9 84.5
Terr-O-Cide 72-27-----. 2.0 .- 8.6 -2.0 49.2 79.0
Terr-O-Cide 72-27. 
2.5 . -- 
13.6 16.0 50.6 
79.0
Terr-O-Cide 72-27- . 3.0 . .... 12.4 3.0 49.7 67.5
Terr-O-Cide 72-27 . 4.0 20.4 29.0 47.6 43.0
DBCP 86 EC
(Fumazone, Nemagon) 1.0 19.4 26.5 6.2 7.0 33.2 20.0
SFigures for yields are averages of eight replications.
** Gulf Coast and Wiregrass fields were infested with the root-knot nematodes, Melo-
idogyne arenaria and M. hapla, respectively; the Summerdale field was infested with race 3
of the soybean cyst nematode (Heterodera glycines).
*** Net return per acre over control calculated on the basis of $5.00/bushel of soybeans,
and cost of Soilbrom 90 EC, Terr-O-Cide 72-27, and DBCP set at 12, 14, and 7 dollars/
gallon respectively.
Continued on Page 19
Auburn University Agricultural Experiment Station18
Continued from Page 18
resistant varieties are planted. Results
also suggest that in heavily infested
fields, levels of Soilbrom 90 EC of 2.0 to
2.5 gal./acre are necessary to maintain
smaller larval populations of M. arenaria
than those in the control and that this
practice results in profitable yield in-
creases.
In the Wiregrass tests, with the excep-
tion of one treatment (Terr-O-Cide 72-27
at 1.0 gal./acre) all applications of the
fumigants containing EDB increased
yields significantly above the control, but
no pattern of response to amount of fum-
igant applied was evidenced. One gal./
acre of Soilbrom 90 EC or 1.5 gal./acre
of Terr-O-Cide 72-27 was sufficient to
attain significant maximal yield response.
Yield response obtained in this experi-
ment to treatment for control of this low
level of infestation reflects the lack of
nematode resistance in Ransom soybeans.
Very likely if a more tolerant variety,
such as Bragg, had been used yield re-
sponses would not have been as great.
Results from the Summerdale test indi-
cated that yields increased somewhat pro-
portionally to the amount of either Soil-
brom 90 EC or Ter-O-Cide 72-27 ap-
plied. Results also confirmed that these
two fumigants were as effective as DBCP
in improving yields. The test at Summer-
dale represents a situation where the
level of infestation was such that a rota-
tion with corn would be recommended;
however, this level of infestation pro-
vided an excellent means of discriminat-
ing between nematicides to quickly de-
termine the relative efficacy of these ma-
terials.
Data from the three experiments show
conclusively that either Soilbrom 90 EC
or Terr-O-Cide 72-27 are good substi-
tutes for DBCP for control of plant para-
sitic nematodes on soybeans. While rates
of 1 gal./acre of the two EDB formula-
tions may be sufficient for treatment of
fields with low to moderate levels of in-
festation with root-knot nematodes, fields
with very severe infestations of either
root knot or the soybean cyst nematode
may require applications of 2 gal./acre
or higher of the fumigants to attain maxi-
mal yield response.
Planting Time and Postemergence Use of Ethylene Dibromide-
Chioropicrin Mixtures for Control of Root-Knot Nematodes
On Florunner Peanuts
THE PEANUT PLANT is subject to attack
by a variety of nematode species which
cause significant yield losses. In Alabama,
the most important parasitic species are
the southern peanut root-knot nematode
(Meloidogyne arenaria), and to a lesser
extent the northern root-knot nematode
(M. hapla), also species of Pratylenchus.
Control of these parasites in seriously in-
fested fields has been primarily effected
through the use of DBCP (Nemagon,
Fumazone) at planting time. Use of this
fumigant resulted in consistently good
control of the parasites for a reasonable
investment ($7-10/acre).
Recent actions by the Environmental
Protection Agency (EPA) have elimi-
nated the use of DBCP on peanuts. Al-
though other contact and systemic nema-
ticides can be used for control of nema-
todes parasitic of peanuts, these materials
are generally either not as effective, or
are more expensive, and their correct use
on peanuts is still under study.
Although the fumigant ethylene dibro-
mide (EDB) is one of the oldest nemati-
cides, its use on peanuts has been re-
stricted because of the general availabil-
ity of DBCP, which was considered to be
three to five times more effective in pre-
R. RODRIGUEZ-KABANA, P. S. KING, H. W. PENICK, Dept. of Botany and Microbiology
HENRY IVEY, Wiregrass Substation
liminary trials with other crops. Planting
time applications of EDB, and especially
of EDB-chloropicrin mixtures, have been
thought to be phytotoxic to peanuts,
hence recommendations for use were
only for preplant application. Because
EDB and EDB-chloropicrin mixtures
could provide acceptable economical
planting time treatments for nematode
control on peanuts, scientists in Auburn
University's Agricultural Experiment Sta-
tion decided to explore the possibility of
their use.
Tests were conducted near Headland,
Ala. on the Marshall Brothers Farm in
a field which was heavily infested with
the southern peanut root-knot nematode
(M. arenaria). In every test each treat-
ment was represented by eight plot repli-
cations arranged into randomized com-
plete block designs. All tests were con-
ducted following recommended cultural
practices for the area.
Planting time applications of the fumi-
gants were effected using a gravity flow
apparatus. The materials were injected
into the soil to a depth of 8 in. using two
chisels per row separated 8 in. apart;
postemergence applications were per-
formed similarly in the first week of July
at midbloom but with the chisels sepa-
rated 10 in. apart. Experiments were
conducted in 1977 and 1978 using the
Soilbrom 90@.EC formulation for EDB
and Terr-O-Cide@ 72-27 (72% EDB and
27% chloropierin).
Soilbrom 90 EC or Terr-O-Cide 72-27
applied at planting during the 1977 sea-
son resulted in yield responses that were
inversely related to nematode numbers.
After a sharp rise in response to the 0.5
and 1.0 gal./acre treatments (table 1),
maximal yields were obtained with rates
of 2.0 gal. or higher; yield differences be-
tween treatments with 2.0 gal./acre or
higher were not significant. The per-
formance of Soilbrom 90 EC (1 gal./
Continued on Page 20
Auburn University Agricultural Experiment Station 19
NV V .' _ -..
A.r e trn 21 .l D a cre1
T-- P
Soi br 111 9 0 E C----------------4 3 339. 19
------------90----C-k j - 4 4 5. 17 ("T1 .
C; J, rer 905 2CS.30-9 21-3
Snl ,I'Orn 90 Ec ---------------- 3.0 4225 4 S 9.21 7053 U
So-4rw 90EC- 42 .04 3.0 32fk(
T& r-O-Cime72----- 0-3 71917
fThlr-o-aCi'e 72-27,------------ --------- j 40 3793 2 7
Ter-r-O-Cirle 7-207 -.----- --- 1.---4-27 4449"
rrz-0.Cide 7 9- 3 10 44
I I -f or varible s uc' " - e '~ i CrI- 11 I o Iv';'
7) C; It z
~' edru- oert~ ~ o u -P )~ '. - n. Pt I '.Lriut aul i
'I'sr -O - nisover 7 t 0A
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acre) compared with DBCP was superior
with respect to yield response but was
similar for degree of nematode control.
Results also indicated that Terr-O-Cide
72-27 (1 gal./acre) was inferior to
DBCP for yield response and degree of
nematode controL
Data from the 1978 test indicated that
planting time applications of Soilbrom
90 EC or Terr-O-Cide 72-27 at rates of
1.5 gal./acre or higher resulted in maxi-
mal yield increments (table 1). Differ-
ences in yield response between these
rates were not significant. Soilbrom 90
EC at the 1 gal. rate significantly in-
creased yield but Terr-O-Cide 72-27 did
not increase yields above the control.
Results from these experiments sug-
gest the superiority of EDB over EDB-
TABLE 2. EFFECT OF POSTEMERGENCE
APPLICATIONS OF ETHYLENE DIBROMIE
(SomBRnoM 90 EC) ON YIELD OF
FLORUNNER P.EANUtrrs w A FIELD
HEAVILY INFESTED WITH THE
SoUTHERN ROOT-KNOT
NEMATODE (M. arenaria)
Yields and returns
Treatment Gal./ 
per acre
acre Pounds 
Dollars**
Coltrol]. .. 2993* .
Soilbrom 90 EC.__ 1.0 3284 49.110
Soilbrom 90 EC 2.0 8160 11.07
Soilbrom 90 EC.__ 3.0 3623 96.30
Soilbrom 90 EC-... 4.0 3134 -18.39
DBCP (at planting)
Nemagon,
Fumazone ........ 1.0 4160 238.07
* Figures for variables are the averages of
eight replications.
** Returns over the control based on
$0.21 per pound of peanuts and Soilbrom
90 EC, Terr-O-Cide 72-27, and DBCP at
12, 14, and 7 dollars per gallon, respectively.
chloropicrin mixtures for control of M.
arenaria. Chloropicrin is mixed with
EDB to provide fungicidal activity to the
formulation, since EDB is strictly a nem-
aticidal fumigant. Consequently, the use
of the more expensive ($12-14/gallon)
Terr-O-Cide 72-27 should be restricted to
fields with nematode-fungal complexes.
Some difficulty was experienced in the
application of Terr-O-Cide 72-27, par-
ticularly in the transfer of material prior
to delivery in the field. This was due to
the lachrymatory properties of chloropic-
rin (tear gas). Our results indicate that
AGRICULTURAL EXPERMENT STATION
AUEURN4 'UNIVERSITY
AjEURN, ALABAMA 36830
L. Dennis Rousc, Director
~uL1C TOK- ichts of
,-cvrukrofResezarc0h379
P. r city for Private Use, 5300
in fields with only nematode problems
Soilbrom 90 EC should be given prefer-
ence. Soilbrom 90 EC proved to be a
good substitute for DBCP; the equipment
needed for its application is the same as
that for DBCP and its price is within an
acceptable range ($10-12/gallon).
Midbloom applications of Soilbrom 90
EC during the 1977 season did not result
in the degree of control obtained with
planting time applications of this fumi-
gant. Yields from Soilbrom-treated plots,
although higher than that for the control,
were not significant. None of the post-
emergence treatments equaled the degree
of control or the yield increments ob-
tained with the planting time treatment
of DBCP at 1 gal./acre.
Results indicate that either EDB (Soil-
brom 90 EC) or EDB-chloropicrin (Terr-
O-Cide 72-27) can be effectively used at
planting time for control of root-knot
nematodes in peanuts without danger to
the crop. Maximal yield responses can be
expected with rates in the range of 1.5-2
gal./acre. Soilbrom 90 EC is as effective
as DBCP for control of root-knot nema-
todes in peanuts and more effective than
Terr-O-Cide 72-27. Florunner peanuts
can tolerate up to 4 gal./acre of Soilbrom
90 EC applied at midbloom using two
chisels/row separated 10 in. apart.
However, the value of such postemer-
gence applications is questionable since
they did not result in as adequate a de-
gree of control or yield response as a
planting time application of the fumigant
at 2 gal./acre.
POSTAGE
OF AGRICU T7R
BIULK L .- 
9M
__