RESEARCH UPDATE
1993
PEANUTS
The 1992 Alabama Performance Comparison
of Peanut Varieties
The number of peanut variet-
ies available to Alabama growers has
increased in recent years, thus placing
greater need for unbiased performance
data regarding varietal selection for
production.
In 1992 a peanut variety test was
conducted at the Wiregrass Substation
in Headland. The experimental design
for the test was a randomized complete
block consisting of two row plots, 20 ft.
long replicated four times. The test
was planted on April 30, 1992, with a
TABLE 1. YIELD OF PEANUT VARIETIES AT THE WIREGRASS
SUBSTATION, HEADLAND, 1992
Variety Yield/acre
Lb.
(R ) M arc I ....................................... 4,538
(V ) N C V 11 ...................... ............... 4 ,392
(R) AgraTech 127 ............... ......... 4,263
(R) GK 7 ........................... ....... 4,084
(V ) V C 1 ............................ .......... 3 ,9 02
(V) NC 7 ........................... ....... 3,902
(R) Florunner ..................................... 3,902
(R) Georgia Runner ............................ 3,721
(R ) Sunrunner .................................... 3,648
(R ) O krun .............................. .......... 3,648
(V) NC 9 .............. ............ ....... 3,467
(V ) Florigiant ....................................... 3,449
(R ) Tam run ........................................ 3,285
(V) NC 10C ....................................... 3,285
(R) Southern Runne ........................... 2,886
(R) Runner Type
(V) Virginia Type
cone planter at a rate of six seed/ft.
Recommended agronomic procedures
were followed regarding fertility, dis-
ease, and insect control. The test was
conducted under irrigation.
Entries considered to be earlier
than Florunner in maturity were dug
on September 4, 1992. These entries
included Marc I, AgraTech 
127, VC 1,
and NC 9. All other entries except
Southern Runner were dug on Sep-
tember 15, 1992. Southern Runner,
considered to be later in maturity, was
Variety
dug on October 2, 1992. Information
concerning relative maturity was pro-
vided by the plant breeder respon-
sible for developing the variety.
The information presented here
represents data for only one year and
one location. Under these circum-
stances performance trends can not
be adequately evaluated, 
however,
performance comparisons between
varieties can be judiciously drawn.
J.P. Bostick, H.W. Ivey, and B.E. Gamble
TABLE 2. GRADE OF PEANUT VARIETIES AT THE WIREGRASS SUBSTATION, HEADLAND, 1992
Sound
mature
Pct.
(R) Marc I ............. ..........................
(V ) N C V 1 1 ................................................
(R) AgraTech 127 ...................................
(R) GK 7 .................. ..................
(V) VC 1 ................. ...................
(V) NC 7 ............... ....................
(R) Florunner ....................................
(R) Georgia Runner ..............................
(R) Sunrunner .....................................
(R ) O k ru n ......... ..... .............................
(V ) N C 9 ........................................
(V ) F lo rig ia n t ........................................
(R ) T a m ru n ........................................
(V ) N C 10 C ........................................
(R) Southern Runner ...........................
(R) Runner Type
(V) Virginia Type
Sound
splits
Pct.
1
1
3
3
1
2
3
3
2
2
2
2
4
1
5
I otal sound
mature kernels
Pct.
66
68
71
70
67
67
69
70
73
71
68
69
71
67
72
Other
kernels
Pct.
8
3
6
7
6
4
6
6
4
6
4
2
6
4
7
ALBMA GIULUA EXEIMN .T~o AuuAUaEs~
New Formulation of Dyfonate Effective
Against Lesser Cornstalk Borers
The lesser cornstalk borer is an
economically important insect pest of
peanuts grown in Alabama. The larvae
of this insect feed on the root crown and
on developing pegs and pods, with
losses in yield exceeding 70% in severe
population outbreaks. Granular insec-
ticides that are applied to the soil at
flowering or at pegging are commonly
used to manage lesser cornstalk borers.
Previous studies have shown that
Lorsban? 15G and Dyfonate? 20G re-
duced survival of lesser cornstalk borer
larvae, compared with larval survival
in soil from untreated plots, five to 14
days after applications in four field
tests. Lorsban also was the longest
lasting insecticide in four experiments.
A new formulation of Dyfonate
has been produced that contains insec-
ticide granules that are coated with
plastic to increase the length of time
that the granules remain effective in
the soil. How does this compare with
the old Dyfonate 20G? AAES scien-
tists did a field test in 1992 to compare
PERCENTAGE SURVIVAL OF SMALL LARVAE OF THE LESSER CORNSTALK BORER IN FIELD PLOTS
Treatment
U ntreated ...........................
Dyfonate 20G ........................
Plastic coated Dyfonate20G..
1 Date of application.
Sample Date
Rate/acre Jun 30' Jul 8 Jul 14
Lb./a.i. Pct. Pct. Pct.
94 67 83
2.0 0 0 17
2.0 0 6 0
Jul 23
Pct.
75
14
3
Jul 27
Pct.
72
47
39
this new for-
mulation of
D y fonate
with several
other granu-
lar insecti-
cides, includ-
ing Dyfonate
20G.
Peanuts
were conventionally planted in a light
loamy sand soil at the Wiregrass Sub-
station in Headland. Twelve treatments
and a control were replicated four times
in a randomized complete block de-
sign, with each plot being six rows
wide and 50 ft. long. Insecticides were
applied at flowering (June 30) in a
seven-in. band over the row with a
small plot granular applicator.
Survival of larvae in untreated soil
was good, ranging from 67 to 94"%. This
is expected, since no insecticides were
in the soil. Both of the Dyfonate for-
mulations gave equivalent percentage
survivals on the date of application
and on July 8. The new plastic-coated
Dyfonate 20G appeared to give better
control of lesser cornstalk borers than
Dyfonate 20G on July 14, 23, and 27.
The new formulation of Dyfonate
should give peanut growers a better
tool to fight invasion by lesser cornstalk
borers. In 1992 test, the plastic coating
on the granule did appear to extend the
effectiveness of the product.
T.P. Mack, S.D. Wolf, and Z. DeLamar
Virus Infections in Peanuts Greater Than Expected in State
An AAES study was conducted
from mid-July to mid-August in 1990
and 1991 to determine the identity and
distribution of the major virus patho-
gens of peanuts in Alabama. Leaves
from peanut plants showing virus-like
symptoms were collected from fields
selected at random in the 14 counties
making up the major peanut produc-
tion area. Symptoms on suspect virus-
infected plants included leaf chlorosis,
mottling, necrosis, line patterns, and
distortion, as well as overall plant
stunting. Leaf samples also were taken
in most of these same fields from plants
showing no apparent 
symptoms. Sap
was extracted from all samples and
tested for peanut mottle virus (PMV),
peanut stripe virus (PStV), peanut stunt
virus (PSV), and tomato spotted wilt
virus (TSWV) by bioassays on indica-
tor plants in the greenhouse, and by
enzyme-linked immunosorbent assays
in the laboratory.
A total of 1,885 peanut plants from
158 fields throughout the 14 county
area were assayed for viruses during
County
Barbour......................
Bullock ........................
Butler .........................
Coffe .........................
Conecuh ....... ............
Covington ...........
Crenshaw ...... .........
Dale .......... ..................
Escam bia ..............
Geneva .......................
Henry ........................
Houston .....................
P ik e ......... ...... ......
Russell ........................
Totals ..........................
Fields Plants PMV PSV TSWV PMV+TSWV
No.
12
8
6
17
7
10
7
12
7
16
19
18
12
7
158
No.
37
113
79
111
108
118
73
149
80
214
243
184
167
109
1,885
the 1990 and 1991 growing seasons, as
shown in the table. PMV and TSWV,
singly or in combination, were identi-
fied in every county and generally at
high frequency in most counties. PSV
was found in all but one of the coun-
ties, but at much lower frequency.
PMV and TSWV were detected in
samples from a majority of the fields
in all 14 counties. PSV was identified
in about one-fourth of the fields sur-
veyed, but these fields were in 13 coun-
ties. No other viruses, including 
PStV,
were identified in any sample during
the two-year period.
These results show that PMV and
Continued on page 4
VIRUSES IDENTIFIED IN PEANUT PLANTS DURING 1990 AND 1991 GROWING SEASONS IN ALABAMA
Plants infected with:
SM9 Spray Adjuvant Fails to Control
Southern Stem Rot of Peanuts in Alabama
In late winter 1992, the spray adju-
vant SM-9 was being marketed to Ala-
bama peanut producers for the control
of white mold and several other de-
structive diseases of peanuts. Claims of
white mold control were based solely
on a single laboratory study and sev-
eral farmer testimonials. Extensive
field research information document-
ing the activity of SM-9 against any
peanut disease 
does not exist. 
Finally,
SM-9 is not registered as a pesticide in
accordance with the requirements of
FIFRA and can only be marketed as a
surfactant. The objective of this study
1
Folicur and Moncut are not registered
for use on peanuts.
was to determine if SM-9 spray adju-
vant had any effect on white mold and
yield of peanut.
Trials were conducted in two
nonirrigated fields in Henry County
that had a history of white mold dam-
age. Florunner peanuts were planted in
late April and maintained according
to recommendations. Fungicides were
applied by hand using a backpack
sprayer on July 1, 14, 27, and August 4.
Hit counts were made the day after
digging, and the plots were harvested
with a combine.
SM-9 spray Adjuvant did not pro-
tect peanuts from white mold. The
numbers of white mold hits were simi-
lar in the plots treated with SM-9 and
the nontreated control plots. On the
other hand, two or four sprays of
Folicur
1 
and single application of
Moncut
1 
gave excellent disease con-
trol. In addition, considerable foliar
burn on the newer peanut leaves was
seen in both fields after each applica-
tion of SM-9. No damage to the foliage
was seen in the plots sprayed with
Folicur or Moncut.
Yield from the SM-9 treated plots
also were similar to those from the
nontreated plots. Yields from all other
fungicide-treated plots were consid-
erably higher than those in the SM-9 or
nontreated control plots. Greatest
yield increases occurred in the plots
treated with two or four applications
of Folicur or a single application of
Moncut.
A.K. Hagan and JR. Weeks
New White Mold Fungicide Increases Peanut 
Yields
White mold is the most damaging
disease of peanuts in Alabama, with
annual losses estimated at 20% of ex-
pected yields. Greatest losses usually
have occurred in fields cropped to pea-
nut every other year. However, a re-
cent two year AAES study indicates the
fungicide Moncut
1 
can drastically re-
duce peanut yield loss to white mold.
Trials were conducted in 16 farm
fields in 1991, and in 21 fields in 1992.
One of the following cropping patterns
was followed in each field: continuous
peanut production (three years mini-
mum), one year peanuts behind one
year corn / grain sorghum /clean 
fallow,
peanuts after two to three years cotton /
corn, and peanuts behind bahiagrass
(five years minimum). Six nontreated
control plots were paired with treated
plots. Treatments were applied ap-
proximately 60 to 70 days after planting
with Moncut 50W at two lb. per acre as
a full canopy spray at 15 gal. total vol-
ume per acre. The occurrence of other
diseases and nematodes was periodi-
cally monitored. Plots were rated for
white mold and Rhizoctonia limb rot
after inverting, then harvested.
1Moncut is not currently registered for
use on peanuts.
In 1991, an 82"/, reduction in the
incidence of white mold was seen in all
Moncut-treated plots across all four
rotations. Lowest level of disease con-
trol (60o%) occurred in those fields
where peanuts followed bahiagrass,
while the best protection from white
mold was noted where peanuts fol-
lowed two or more years of corn or
cotton. Despite heavy disease pressure,
yield increases after treatment with
Moncut (23.3%) were largest where
peanuts were grown every other year.
Despite modest disease pressure, yield
increases of 14% also were obtained in
fields cropped to peanuts every third
year. Smaller yield increases were seen
in fields in continuous peanut produc-
tion. In peanuts behind bahiagrass,
disease pressure was light and no yield
gains were noted. Overall, an applica-
tion of Moncut increased average pea-
nut yields across all rotations
by 18.1"% over that of the un- 
WHI
treated plots. Yield increases
in selected fields under severe
white mold pressure were in
the range of 40 to 45% (1,700
Peant
lb. per acre). 
Pean
In 1992, Moncut provided Pean
85'X control of white mold 
Contir
across all rotations, see table. Avera
Best disease control occurred in those
rotations with heaviest white mold
pressure. Sizable yield increases were
noted in all rotations except bahia-
grass-peanut, where little white mold
was present. Overall, yields from the
Moncut-treated plots were 19.4% higher
than from the untreated controls across
all rotations.
In both years, superior control of
white mold and yield increases were
obtained with a single application of
the unregistered fungicide, Moncut.
Greatest yield increases consistently
occurred in those fields where white
mold historically has caused extensive
damage. Where disease pressure was
low, such as whenever peanuts were
cropped after bahiagrass, Moncut had
little impact on yield.
A.K. Hagan, J.R. Weeks, K.L. Bowen, W.A. Miller,
and D.L. Hartzog.
TE MOLD CONTROL AND YIELD INCREASES IN PEANUTS TREATED
WITH MONCUT, 1992
Rotation
uts after bahia (5)...
uts every 3 year (9)
uts every 2 year (4)
nuous peanuts (2)..
g e ........... .........
Control Yield increases
Pct. Lb./a Pct.
60 -63 -1.6
78 502 11.1
85 743 20.4
89 768 19.3
85 19.4
AU-Pnuts Expert System Looks Promising
For Management of Peanut Leafspot
Peanut producers interested in
protecting their crops, their profit mar-
gins, and the environment don't have
to exhaust their pest defense budgets
on high-tech weapons. They can enlist
the help of two long-time agricultural
allies a rain gauge and a weather fore-
cast.
These tools can be put to use via an
overall pest management program
known as AU-Pnuts that is now being
developed by the Alabama Agricul-
tural Experiment Station at Auburn.
AU-Pnuts is a rule-based "expert sys-
tem" that utilizes the same logic an
expert would apply to make manage-
ment decisions.
The need for a low-cost, environ-
mentally sound management system
was the stimulus for AU-Pnuts, which
is being developed through support
from the Experiment Station, the Ala-
bama Peanut Producers Association,
and a USDA Southern IPM grant. The
goal of the project is to develop and
evaluate a system to manage diseases,
and nematodes attacking peanuts in
Alabama.
The total AU-Pnuts program even-
tually will encompass management
schedules for leafspot and other dis-
eases such as white mold and limb rot,
and also for other peanut pests such as
nematodes.
Research has shown that leafspot
can be effectively managed if the first
fungicide application is made when
EDITOR'S NOTE
Mention of comfpa7tlny or trade rtinaics does
not inlicate endorseimetiiI by the Alabanma
Agricultural Exp riment Station orAuiburn
University of one hbrand over another. Any i
imenttion of noniabel uses or ap/lications in
excess (off Ilabe'ld rates of pesticides or other
chlemlicals does hot constitute a 'recoillfllelda-
tion. Such use in research is simply part ofthe
scicl tific investiation necessary tofully evalu
ate materials a1d treatruents.
Inifrmaiti tion contained hertieini is available to
all persons without regard o race, color, sex, or
nationial origin,.
six rain events of 1/10-in. or greater
have occurred following emergence of
the plants. Subsequent sprays can then
be made following the 10-day protec-
tion window when it has rained or is
predicted to rain for three additional
days.
On-farm validation tests of the
module have been conducted at sites in
five counties in Alabama's eastern pea-
nut belt in the southeastern part of the
state. On farms where AU-Pnuts was
used correctly, the program signifi-
cantly improved season-long disease
control and also increased yields an
average of 258 lb. per acre in four of the
five fields where vields were corn-
pared.
These tests also showed that farm-
ers can use AU-Pnuts without too much
trouble once they have undergone a
brief training session to explain the
rules.
Though the total AU-Pnuts system
is not yet ready for use, researchers are
optimistic that this will soon provide
peanut growers an effective option for
pest management at a cost that is pea-
nuts compared to the computerized
models.
For more information on AU-
Pnuts or for detailed rules, contact
your local Cooperative Extension Ser-
vice office.
P.A. Backman
Virus Infections , continued
TSWV were prevalent throughout the
peanut production area, and that PSV
occurred at lesser, but significant levels
as well. Generally, incidence of all the
viruses was higher than was previously
suspected. The impact of these viruses
on the peanut crop in Alabama has not
been determined; however, their po-
tential for causing serious losses has
been well documented in other states.
R.T. Gudauskas, K.B. Burch. P. Jin, 
A.K. Hagan,
and J.R. Weeks
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