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In this article we will discuss about the diseases and management of Grain Smut.
Disease of Grain Smut:
In India, the grain smut disease (Macalpinomyces sharmae) was first reported by Sharma and Khare (1987) from Dindori district of Madhya Pradesh. Later on, the disease was also reported from other parts of the country in sporadic from.
Sharma and Khare (1987) noticed up to 50 per cent plants/grains affected by the pathogen. Jain and Tripathi (2007) reported grain smut incidence ranging from 5.9 to 31% and 5.0 to 7.8% in the fields at Rewa and Dindori in Madhya Pradesh during 1997 to 2005.
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Jain (2006) and Jain and Tripathi (2007) recorded 9.8 to 53.55 per cent reduction in grain yield per plant, 4.2 to 16.6 per cent in plant height and 6.4 to 38.9 per cent in panicle length.
The symptoms of the disease become visible at grain formation stage. The affected ovary converts into smut sorus, but does not increase in size than the normal grain. The glumes are pushed apart by the transformed spore balls (sori).
The sorus remains covered by thin dull delicate membrane, which is easily pushed away leaving exposed sorus. The spores are easily blown away leaving nothing inside the glumes. Some of the grains developed late, remain greenish and increase in size slightly over the normal grains. Such grains- release spores on pressing.
Management of Grain Smut:
The disease can be controlled by adopting cultural practices, resistant cultivars and chemicals. Genotypes Varisukdhara (2), RLM 13 (3), RLM 14 (1), OLM 203 (5), VMLC 281 (2) VMLC 296 (3) OLM 40 (3) DPI 2394, PLM 202, OLM 203, DPI 2386 and CO 2 were found highly resistant to grain smut.
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Seed treatment with Carboxin or Carbendazim at the rate 2 g/kg seed has been found to be economical and effective. The disease can also be controlled by seed treatment with carboxin at the rate 2 g/kg seed + one foliar spray of Carbendazim (0.05%).
Besides grain smut, rust (Uromyces linearis), Udbatta disease (Ephelis oryzae), leaf blight (Helminthosporium nodulosum), sheath blight (Rhizoctonia solani) etc. are some other diseases which are of minor importance to this crop.
