Symptoms :

• The grains may be infected by various organisms before or after harvesting causing discolouration, the extend of which varies according to season and locality.
• The infection may be external or internal causing discoloration of the glumes or kernels or both.
• Dark brown or black spots appear on the grains.
• The discolouration may be red, yellow, orange, pink or black, depending upon the organism involved and the degree of infection.
• This disease is responsible for quantitative and qualitative losses of grains.

Favourable Conditions:

• High humidity and cloudy weather during heading stage.

Mode of Spread and Survival:

• The disease spreads mainly through air-borne conidia and the fungus survives as parasite and saprophyte in the infected grains, plant debris and also on other crop debris.

Management:

• Pre and post-harvest measures should be taken into account for prevention of grain discolouration.
• Foliar spray of Neem oil @ 3 per cent at 50 % flowering stage followed by second spray 10 days later.
• Seed treatment with Thiram at 4 g/kg or Bacillus subtilis (TNAU) @ 10g/kg .
• Foliar spray with thiophanate methyl 70% WP or hexaconazole 4% + zineb 68% WP 400 gm per acre at 50 per cent flowering.

Source of information:

• AICRIP rice, TNAU, Coimbatore, Rice diseases- online resource, IRRI, Phillippines.

• IRRI, Phillippines

Acknowledgements: