Revised January 1948
SEED TREATMENT /r PEANUTS
COYT WILSON, Plant Pathologist
P OOR stands of peanuts, which cut
growers' profits, may be caused by one
of several conditions. Seed rot, how-
ever, is one of the most common causes of
poor stands.
Much of the seed rot can be prevented
by treating seed with the proper disin-
fectant (chemical compound). The results
given here are from 5 years' work 
at the
Alabama Agricultural Experiment Station.
They are similar to results obtained by other
investigators working on the same problem.
VALUE of SEED TREATMENT
High yields of peanuts are dependent on
good stands (Figure 1). Soil fertility,
growing conditions, insect and disease
damage, and weather conditions during
I. Original printing I3M, .Jnuary 194-.
Re\ision 5NM, January 194N.
FIG-kL: i,
11C r
harvest time influence total yields. How-
ever, high yields cannot be expected from
fields of poor stands. Treating the seed
with a chemical seed disinfectant may
mean the difference between good and poor
stands of peanuts.
WHAT IT DOES
Seed treatment serves two purposes.
The disinfectant kills the organisms pres-
ent on the seed surface that cause seed-
rotting and seedling disease. It also pro-
tects the seed against similar organisms that
are present in the soil.
This latter protection is especially im-
portant on machine shelled seed, because
seed coats are broken frequently by the
machine. Unless the seed are covered by a
disinfectant, broken skins are ideal places
for entramcc of ced-rotting org~anisms.
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AGRICULTURAL EXPERIMENT 
STATION
of the ALABAMA POLYTECHNIC 
INSTITUTE
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M. J. Funchess, Director
Auburn, Alabama
t-
FIGURE 2. Seed -rea-ments do not pre-
vent seedling blights and roof rots of peanuts,
as shown above. However, seed treatments
do result in more seedlings. Thus, damages
from seedling blights and r o rots are re-
duced.
This protection during germination also
gives the young seedling a better chance to
become established before disease organisms
attack and produce stem and root rots
similar to those shown in Figure 2. Since
seed treatment usually results in more
plants, the loss of a few from seedling
blights is not as serious in stands from
treated seed as in those where untreated seed
are planted and stands are weak.
MACHINE vs. HAND-SHELLING
Treatment is more important on ma-
chine-shelled seed than on either hand-
shelled or unshelled seed. Good stands
usually can be obtained from hand-shelled
seed without treatment. Treating such
,eed results in only 5 to 10 per cent more
seedlings. Treatment of machine-shelled
seed usually increases the number of plants
from 30 to 50 per cent.
Unshelled seed generally yield poor
stands, and treatment causes very little im-
provement. These facts are shown in Table
1.
MATERIALS USED
A number of different seed-treating
materials have been tested on both Spanish
and runner peanuts. All of the materials
have improved the stands, but some have
given better results than others. The re-
sponse to seed treatment of Spanish and
runners is about the same. Table 2 sum-
marizes the results obtained at the Main
Station, Auburn, over a period of 5 years.
Two per cent Ceresan and DuBay 1452-F
have been two of the best treatments
throughout the tests. However, these ma-
terials contain mercury and are poisonous.
They must be handled with caution, and
seed treated with either of these should be
planted or destroyed. In addition to the
danger to people and livestock, there is the
hazard of using too much of these materials
on the seed. Overdosage with any mer-
cury compound causes abnormal germina-
tion. The first root becomes greatly en-
larged, root branching is retarded, and the
young leaves develop very slowly. Quite
frequently these seedlings die. Such symp-
toms are shown by the plants in Figure 3.
TABLE 1. EFFECT OF METHOD OF SHELLING AND SEED TREATMENT ON EMERGENCE
OF SPANISH PEANUTS, AUBURN, ALABAMA, 1943-44
Method of shelling
Not shelled
Not shelled
Hand-shelled - .
Hand-shelled
Machine-shelled
Machine-shelled
Disinfectant
.- None
.2'c Ceresan
..- None
... 2' Ceresan
None
2 ; Ceresan
Average number of
plants from 100 seeds
TABLE 2. EFFECT OF VARIOUS SEED DISINFECTANTS UPON EMERGENCE OF MACHINE-
SHELLED SPANISH AND RUNNER PEANUTS AT MAIN STATION, 
AUBURN, ALABAMA
Disinfectant
Rate of applica-
tion per 100
pounds of
shelled seed
Ounces
None
Merc-O-Dust
Dow 9B
Yellow Cuprocide
Spergon
Arasan
Phygon
Ceresan, 2%
DuBay 1452-F
New improved Ceresan should never be
used, because it contains 5 per cent of the
mercury compound. Injuries to the seed
are almost certain to result from use of this
compound.
I)uBay 1452-F is now on the market
under the name of Ceresan M. When used
at 1,'2 ounces per 100 pounds of seed, it
has been very satisfactory, but it should be
used with caution. Overdosage may cause
mercury injury. Spergon and Arasan are
reliable materials that are not dangerous to
handle. They do not cause injuries to the
germinating seed, even when used in ex-
cess. The two materials appear to be about
equally effective under Alabamai conditions.
Average number of
plants from 100 seeds
Spanish Runners
Per cent
48
69
65
66
71
62
78
86
Per cent
58
67
71
73
79
83
80
87
85
Spergon is not dusty and is not irritating to
the eyes or nasal passages. Arasan is more
disagreeable to handle, but is less expensive
than Spergon. Phygon is easily handled
and is quite effective. The dangers of
overtreatment with this material have not
been investigated. Dow 9B was not as ef-
fective on runner peanuts as other tested
materials. It has a disagreeable odor, but
it is not as dangerous to handle as the mer-
curial treatments.
WHEN to TREAT
Seed may be shelled and treated during
the winter months when labor is more
abundant. In tests conducted at the Main
FIGURE 3.
r :q t were treated atn dn overduse ot 
Cresn. No-e -no en arged 
-r r: 's. Ie two at the
left are from seed treated at he recommerded 
rate.
Station,
2 
seed shelled and treated 9 weeks
before planting have produced stands as
good as those shelled and treated one day
before planting. These tests have been in
progress for 3 years. In no instance has
there been any significant difference in the
stands obtained from seeds shelled on the
different dates. The results given in Table
3 were obtained in 1946; they are in agree-
ment with those obtained in earlier years
in other tests.
After the seed are shelled and treated,
they should be stored in a dry place. Under
such conditions they will keep for several
months. Seed shelled, treated, and stored
in screened cages at Auburn have germi-
nated as well 15 months after shelling as
they did at the time they were shelled.
Usually, though, it is impractical to carry
treated seed over from one year to another
because of the webworms that get into seed.
HOW to TREAT
The method used to apply the disinfect-
ant will depend upon the volume of seed
2. All machine-shelled seed used in these
experiments were shelled by the USDA
Tillage Machinery Laboratory, Auburn,
Ala., on a portable sheller designed and
built by that laboratory.
to be treated. Whatever method is used,
it should insure uniform distribution of
the disinfectant over every seed. For
greatest efficiency each seed should be
coated with a film of the chemical dust.
Some disinfectants will evaporate, and the
vapors that enter the sack of seed will kill
the disease-producing organisms on the
seed. However, the seed will be re-infected
as soon as they are placed in the ground,
unless covered with the disinfectant.
Thorough coverage is especially important
on machine-shelled seed.
Most commercial peanut shellers are
equipped to treat seed. If the grower has
access to a reliable sheller, it is usually
more practical to buy treated seed or to
have the sheller treat the seed at the time
they are shelled.
For the grower who wishes to shell and
treat his own seed, the rotary seed treater
or one of the gravity seed treaters is satis-
factory.
3
Always plainly label treated seed and use
them only for planting. Treated seed
should not be used for human food, live-
stock feed, or sold to oil mills.
3. Details for construction of these seed
treaters may be obtained from the Agricul-
tural Experiment Station, Auburn, Ala-
bama.
TABLE 3. EFFECT OF TIME OF SHELLING AND SEED TREATMENT ON THE EMERGENCE
OF HAND-SHELLED'AND MACHINE-SHELLED RUNNER PEANUTS
Method of Seed 
Time elapsing between shelling 
and planting
shelling treatment Nine weeks Six weeks Three weeks One day
Per cent Per cent Per cent Per cent
Hand None 71 80 80 80
Hand ................. 2% Ceresan 85 86 82 86
Machine------- None -- - 64 64 51 44
Machine...... 2% Ceresan 80 79 83 80