Grain mold

(Caused by a complex of several fungal species)

 Symptoms

• Initial symptoms of grain mold are discoloration of grains due to infection and colonization by mold fungi.
• Grain discoloration varies from light whitish, pinkish, grayish, to shiny black depending on infection and colonization by individual fungal species. Often grains are colonized by multiple fungi.
• In severe cases, grains turn completely black. In case of severe infection at anthesis, grain development is affected resulting in chaffy florets or small grains on the panicle.
• High humidity (>90% RH) due to frequent rains and a temperature range of 25-35˚c during the flowering to grain development period are quite favorable for infection and development.

 

Fig. 1: White fungal growth on the grain

Control measures

• Grow mold resistant cultivars, such as SPV 422, SSV 84, NTJ 2, ICSV 700 and CSH 22SS.
• Avoid growing early-maturing mold-susceptible cultivars whose flowering coincides with the rainy season.
• Harvest crop at physiological maturity and quickly dry grains   after threshing Avoid delay in harvesting the matured crop.
• Chemical control is not suggested for grain mold because it is impracticable and uneconomical, except in seed production plots on  research stations depending on importance of genetic material.
• Some level of control can be obtained by three sprays on earheads with Aurofungin -200ppm and 0.2 % Captan starting from flowering to grain maturity with 10 day intervals under rain free conditions.