Effective management of diseases
that affect the peanut crop is essential
to successful peanut production.
Producers should carefully
plan an effective strategy to manage
diseases and nematodes based on the following
factors and with the use of Peanut
Although no variety is immune to
TSWV, newer varieties have improved resistance
to spotted wilt and to fungal diseases,
which will likely lead to a reduction
in disease severity. Remember, improved
resistance to one disease does not mean
that the variety also possesses superior resistance
to other diseases.
In general, early planted and lateplanted
peanuts tend to have higher levels
of TSWV than those planted in the
middle of the planting season. For larger
acreages, it may be more effective to plant
varieties with different time-to-maturity
requirements as closely as possible within
a low-risk time period. If planting during
a high-risk period, try to minimize the
risk associated with other index factors.
Research has confirmed the impact of
plant population on TSWV incidence, but it has less effect on fungal diseases.
However, for white mold, it is now
known that severity increases when the
space between the crown of individual
The use of insecticides to control thrips
vectors has been an ineffective means of
suppressing TSWV. However, one chemical
- phorate (Thimet 20G and Phorate
20G), has demonstrated consistent, lowlevel
suppression of TSWV. It is thought
that phorate may induce a defense response
in the peanut plant.
Seven to 10-inch twin-row spacing,
utilizing the same seeding rate per acre as
single row spacing, has become popular.
Research has shown that white mold is
more severe in single rows at six seed per
foot than in twin rows at three seed per
foot. The difference in leaf spot appears
to be negligible.
Spotted wilt is less severe in strip-tilled
fields, as is leaf spot, if peanut is not
planted in consecutive seasons. Use of
conservation tillage does not eliminate
the need for fungicides to control leaf
spot, but helps to insure added disease
control from a fungicide program.
White mold may be slightly more severe
in strip tillage; deep turning the soil
may help to reduce the threat to white
mold by burying initial inoculum.
Research has confirmed that the use
of Classic (chlorimuron) can occasionally
result in an increased expression of
tomato spotted wilt of peanut. However,
results indicate that the effects are minimal
in comparison to the other production
practices that influence this disease.
To date, other peanut herbicides have
not been shown to have an influence on
Crop rotation is one of the most important
tactics to reduce disease severity
in peanut production and production of
all crops. Increasing the number of seasons
between consecutive peanut crops
in the same field has been shown to reduce
disease levels and increase yield.
Choice of rotation crops will also have
an impact on disease.
Fields where growers have had difficulty
managing disease in the past, despite
the implementation of a good fungicide
program, are more likely to have disease
problems in the future than are fields with
less histories of disease.
Irrigation is a critical component of a
production system and can result in large
peanut yields. However, moisture coupled
with increased soil temperatures may
create conditions favorable for disease
more so than non-irrigated fields.
For more complete information on
minimizing disease in peanut, visit
www.ugapeanuts.com or contact your
state Extension peanut pathologist.