Ergot (Claviceps spp.)
Cream to pink sticky "honeydew" droplets ooze out of infected florets on panicles. Within 10 to 15 days, the droplets dry and harden, and dark brown to black sclerotia (fungal fruiting bodies) develop in place of seeds on the panicle. Sclerotia are larger than seed and irregularly shaped, and generally get mixed with the grain during threshing. Conditions favouring the disease are relative humidity greater than 80%, and temperatures between 20 to 30 degC.
The sclerotia falling on the soil or planted with the seed germinate when the plants are flowering. They produce spores that are wind-borne to the flowers, where they invade the young kernels and replace the kernels with fungal growth. The fungal growth bears millions of tiny spores in a sticky, sweet, honeydew mass. These spores are carried by insects or splashed by rain to infect other kernels.
- Plant resistant varieties, where available.
- Remove affected panicles.
- Avoid planting seeds from infected panicles.
- Plough deep.
- Rotate with non-cereals preferably with pulses.
- Practise good field sanitation.