Annals of Plant Protection Sciences

Seven types of black point symptoms were established based on the discolouration of seeds. Light brown to dark brown/black discolouration of embryonic region (symptom type-3) was observed as the predominant symptom of black point discolouration (62.5%) followed by embryonic end (lower side) dark brown to black (symptom type-2). Three different pathogens viz. Alternaria alternata, Bipolaris sorokiniana and Curvularia lunata, were found to be dominantly associated with black point infected seeds with significantly varying frequencies of association with different types of discolouration. Maximum incidence (90%) of A. alternata was detected in seeds with embryo region and surrounding endosperm area dark brown to black. Incidence of B. sorokiniana was maximum (52%) in seeds with embryo region (upper side) light brown and of C. lunata in seeds with embryo region (upper side) dark brown to black (92%). Irrespective of the symptomatic category, the disease significantly affected the seed quality like test weight, seed viability, germination percentage and seedling vigour of black point affected seeds. Incidence of black point was found more in case of bread wheat grown in rain-fed conditions (5.29%) as compared to irrigated conditions (1.70%).