This document describes the symptoms and management strategies for several peanut diseases. It notes that peanut diseases can cause chlorosis, wilting, stem discoloration, leaf spots, and pod damage. Management involves practices like deep plowing of crop debris, crop rotation, irrigation, weed control, and in some cases fungicide application. The fungus that causes these diseases can survive in the soil for years.

6. SYMPTOMS
 Leaves on main stem
turning chlorotic and
wilting; entire plant wilts
very rapidly when there is a
period of water stress
following high moisture;
clusters of red-brown
fungal bodies occur on on
stems, pegs and pods;
roots destroyed; roots
blackened and shriveled

7. CLUSTERS OF FUNGAL FRUITING
BODIES ON PEANUT STEM
PLANTSYELLOWING AND
WILTING

15. PEANUT PLANT INFECTEDWITH
CERCOSPORA FUNGUS
PEANUT PLANT INFECTEDWITH
CERCOSPORA FUNGUS

16. SYMPTOMS
 Characteristic orange
pustules on undersides of
leaves which become
covered in masses of red-
brown spores; pustules
may form on pods

17. SYMPTOMS
 Lateral branches or main stem yellowing and
wilting; white fungal mat developing on the stem
close to the soil line; white to brown spore
containing structures developing from the fungal
mats
 Cause
 Fungus
 Comments
 Pathogen has a large host range and attacks many
crops including sugar beets; disease favors dry
soils which crack deeply, allowing the penetration
of oxygen
 Management
 Plow crop debris deeply into soil after harvest of
crop; crop rotation of 3-4 years are very effective
at reducing soil inoculum in the case of severe
infestations; applications of appropriate fungicides
can help suppress stem rot but care should be
taken with selection as some pesticides (e.g.
benomyl) are known to increase the severity of the
the disease

18. SYMPTOMS
 Chlorosis of leaf margins; curling leaves; loss of
leaf turgor; plants wilt and become stunted as the
disease progresses; plants wilt rapidly during
periods of water stress; vascular system becomes
dicolored
 Cause
 Fungi
 Comments
 Fungus can survive in the soil for several years;
disease is spread to uninfested fields by
movement of infested soil or contaminated tools
and machinery; there are no peanut varieties
known to have resistance to the disease
 Management
 Irrigate plants frequently to reduce wilting of
infected plants and allow them to reach maturity;
eliminate weeds int he plantation which may allow
inoculum to build up in the soil; remove and
destroy infected crop residue after harvest to
reduce inoculum in the field


19. SYMPTOMS

Seed and un-emerged seedlings
attacked by the pathogen are rapidly
shriveled and dried. Brown or black
mass covered by yellow or greenish
spores may be seen. Decay is most
rapid when infected seeds are planted.
After seedling emergence cotyledons
already infected with the pathogen,
show necrotic lesions with reddish
brown margins.This necrosis
terminates at or near the cotyledonary
axis. Under field conditions the
diseased plants are stunted, and are
often chlorotic.The leaflets are
reduced in size with pointed tips,
widely varied in shape and sometimes
with veinal clearing

20. SYMPTOMS
 This disease can result in poor
stands after planting and/or
death of entire plants soon after
emergence of seedlings.As
plants develop woody stems and
tap roots, this disease is less
likely to occur.The succulent and
elongating hypocotyl of
seedlings is highly susceptible to
this disease. Diseased tissues
will appear sunken and tan to
dark brown in color. Masses of
black sooty spores of the fungus
usually cover the decayed
tissues.

21. SYMPTOMS
 Circular, brown-black lesions
on the upper surfaces of the
leave; web or net-like brown
lesions on leaves may form on
leaves during periods of high
humidity; as sisease
progresses, lesions darken
and develop a rough texture;
lesions may cover entire leaf
surface

22. SYMPTOMS
 Numerous spots on upper surface of
leaflets; entire plant or discrete parts may
wilt and die; pods and stems become
covered in fungal sclerotia
 Cause
 Fungus
 Comments
 Disease emergence favors high moisture
and high temperature; plants damaged by
frost or other pathogens are particularly
vulnerable to attack
 Management
 Avoiding frost damage by planting early
peanut varieties can help protect the plant
from fungal colonization; application of
appropriate foliar fungicides (e.g. benomyl),
where available, can help to control the
disease