Diplodia Ear Rot
(no mycotoxins)
- Wet weather during grain fill and upright ears with tight husks promote Diplodia
- Diplodia may cause ear rot, stalk rot or seedling blight
- Corn is only known host
- Wet weather plus moderate temperatures allow infection to occur if spores are present during early silking to two to three weeks after silking
- Diplodia is highly dependent on quantity of infected, unburied corn residue (stalks, cobs and kernels)
Fusarium Ear Rot (produces mycotoxins)
- Most common fungal disease on corn ears
- Fungi survive on residue of corn and other plants
- Most severe when weather is warm and dry
- Disease enters ear primarily through wounds from hail or insect feeding
- Scattered or groups of kernels are typically affected
- Mold may be white, pink or salmon-colored
- Infected kernels may turn tan or brown
- “Starburst” pattern often associated with the disease
Gibberella Ear Rot
(mycotoxins may occur)
- Infects other cereals – causes head scab of wheat
- Overwinters in infected crop residue
- Spores are spread from crop residue to corn ears by wind and rain splash
- Infection of corn ears occurs through young silks
- Infection favored by cool, wet weather during and after pollination (optimum temps 65 to 70º F)
Aspergillus Ear Rot
(mycotoxins may occur)
- Most common under drought conditions, high temperatures (80-100º F) and high relative humidity (85%) during pollination and grain fill
- Gray-green, olive, yellow-green or yellow-brown powdery mold growth on and between kernels
- Surface mold can develop anywhere on the ear
- Symptoms are often found at damaged areas of ear