Grain mould (sorghum/millets)
Pink, grey, black or white mouldy, discoloured grain when the crop matures in wet, humid weather — lighter, weaker, and possibly mycotoxin-laden.
- Pathogen
- Fungal complex (Fusarium, Curvularia, etc.)
- Spreads by
- Air/rain-splashed spores onto wet grain
- Favoured by
- Rain & humidity during grain fill/maturity
- Main risk
- Discoloured, light grain; poor seed; mycotoxins
Overview
Grain mould is not a single disease but a complex of many fungi (Fusarium, Curvularia and others) that colonise the developing and maturing grain of sorghum (and pearl millet) when the grain fills and ripens in wet, humid weather. The grain becomes discoloured and mouldy — pink, grey, white or black — with fungal growth on and inside it, instead of clean, bright, well-filled grain.
Mouldy grain weighs less, is of poor quality and market value, germinates poorly as seed, and — importantly — can carry mycotoxins that make it unsafe for food and feed. The problem is worst when maturity coincides with rain and high humidity, and in early-maturing, coloured or compact-headed types whose grain sits wet. Management combines choosing tolerant (often tan/hard-grained, loose-headed) types, matching maturity to avoid a wet harvest window, and timely harvest and proper drying, plus a fungicide at flowering/grain fill in high-risk situations.
How to identify it
- Grain discoloured and mouldy — pink, grey, white or black — with fungal growth on and inside it.
- Lighter, poorly-filled grain of low quality and market value, instead of clean bright grain.
- Poor germination when such grain is kept as seed.
- Worst when the crop matures during rain and high humidity, and in coloured/compact-headed types.
What causes it and when
- A complex of many fungi (Fusarium, Curvularia and others) colonising the developing and maturing grain.
- Favoured by rain and high humidity during grain fill and maturity, when the grain stays wet.
- Worse in early-maturing, coloured or compact-headed types whose grain sits moist.
- Some of the fungi produce mycotoxins, making the grain unsafe for food and feed.
Cultural & organic control
- Choose tolerant types — often tan/hard-grained, loose-headed varieties — that resist mould.
- Match maturity to the season so grain fill and harvest avoid the wettest, most humid window.
- Harvest promptly at maturity and dry the grain quickly to a safe moisture; do not let mature heads stand in the rain.
- Use clean seed and avoid over-dense, lodged crops that keep the heads wet.
Chemical control
- In high-risk situations, a CIB&RC-registered fungicide sprayed at flowering/early grain fill can reduce mould.
- The bigger levers are variety choice, maturity timing, and prompt harvest and drying.
- Observe the pre-harvest interval, and keep mouldy grain out of food/feed because of mycotoxin risk.
- Confirm the current product and any spray recommendation for your crop with your local KVK.
Prevent it coming back
- Grow tolerant, well-adapted types and time maturity to avoid a wet harvest window.
- Harvest promptly and dry the grain quickly, and store it dry.
- Use clean seed and avoid the dense, lodged, slow-drying crops that grain mould loves.
Crops most at risk
Where this problem is called out in our crop guides — open a crop for the full package of practices.
Frequently asked questions
My sorghum/bajra grain is discoloured and mouldy — pink, grey or black. What is it?
That pink, grey, white or black mouldy, discoloured grain is grain mould, a complex of fungi that colonise the grain when the crop matures in wet, humid weather. The grain is lighter, poorer quality, germinates badly and can carry mycotoxins. Choose a tolerant (tan/hard-grained) type, time maturity to avoid wet weather, harvest promptly and dry the grain quickly, and keep heavily mouldy grain out of food and feed.
Is mouldy sorghum/millet grain safe to eat or feed?
Not necessarily — some of the fungi in grain mould produce mycotoxins, so heavily mouldy grain can be unsafe for both people and livestock and should be kept out of food and feed. Even where toxins are low, the grain is lighter and of poor quality. The safest approach is to prevent mould by matching maturity to dry weather and harvesting and drying promptly, and to clean and separate mouldy lots rather than consuming or feeding them.
Why do some sorghum types get much less grain mould?
Because grain mould is strongly influenced by grain type and head structure. Tan or hard-grained, loose-headed types tend to resist mould much better than soft, coloured, compact-headed types whose grain sits wet and packed. Choosing a tolerant, well-adapted variety and matching its maturity so grain fill and harvest miss the wettest, most humid window is one of the most effective ways to avoid grain mould, alongside prompt harvest and drying.
Symptoms and control measures follow ICAR, KVK and state agricultural-university package-of-practices; any named chemical is a registered use. Always read the product label and confirm the dose for your crop and zone. editorial policy.