This web page address is: http://www.btny.purdue.edu/Extension/Pathology/CropDiseases/Corn/corn3.html
Disease Name: Fusarium Ear Rot
Pathogen: Fungus. Fusarium moniliforme
Symptoms: Seldom involves whole ear, rot usually
occurs at tip of ear or in scattered areas on ear, color of
fungal mycelium around infected kernels varies from white to
faint pink to reddish brown. Infected kernels vary in color
from light to dark brown.
Conditions: Dry, warm weather. Infection occurs through
injury by insects or environmental stress.
Pathogen: Fungi. Aspergillus flavus, A. glaucus,
Symptoms:Aspergillus niger appears as a
black mold on infected kernels. A. flavus is a greenish-yellow
mold growing on damaged kernels. A. glaucus is a greenish
Conditions:A. flavus is more common in Indiana
following hot, dry weather, injury by drought stress and insect
damage. Mold growth in storage when moisture is higher than 18%. A.
flavus can produce a carcinogenic secondary metabolite known
Pathogen: Virus. Maize dwarf mosaic virus (MDMV) strain
A or B
Symptoms: Stippled mottle or mosaic of light and dark
green on the youngest leaves (may develop into narrow streaks).
Upper internodes may be shortened. Older leaves may become
blotched with red streaks.
Conditions: Those favorable to aphids and growth of Johnsongrass
Inoculum Survival: Weeds (rhizomes of perennial Johnsongrass).
Symptoms: Partial to complete replacement of the normal
tassel by a large, bushy mass of small leaves. No pollen is
produced. Ear formation may also stop, causing ear shoots to
be numerous, elongated, leafy and barren. Plants may be stunted
or taller than average.
Conditions: Saturated soil conditions for 24-48 hours.