Black Point Of Wheat Caused By Bipolaris Sorokiniana And Its Management
240Black point of wheat is prevalent in most of the wheat growing regions of the world. It reduces grain quality and germination. Symptoms of black point are easily recognizable by deposition of black fungal mass at the embryo end of the seed. Out of a number of fungal pathogens involved in the black point, B. sorokiniana dominates in the warm humid climate of South Asia. Black point appears due to invasion of seed surface by direct penetration of hyphae to outer layers of the pericarp or through stigma to the pericarp. This disease can be artificially produced by inoculation of spore suspension in the floral cavity between the lemma and palea. A scale has been developed for monitoring the quality of grain and black point severity. Warmer temperature and high relative humidity during grain filling period favors black point. Severity of black point increases many fold when rains occur during grain filling period. Genotypic variation for black point severity has been recorded in wheat germplasm. Foliar spray of sterol inhibiting fungicides was found effective in controlling this disease.