Oilseed brassicas also known as rapeseed-mustard is an important group of oilseed crop in the world. These crops are susceptible to a number of diseases caused by biotic and mesobiotic pathogens. Among various diseases, Alternaria leaf blight also known as Alternaria dark spot is the most destructive disease of oilseed brassicas species in all the continents. This disease is known to be incited by Alternaria brassicae, Alternaria brassicicola and Alternaria raphani singly or by mixed infection. Alternaria leaf spot pathogens are necrotrophs and produces lesions surrounded by chlorotic areas on leaves, stems and siliquae causing reduction in the photosynthetic areas, defoliation, and early induction of senescence. Alternaria blight causes considerable reduction in quantity and quality of harvested brassica products. The Alternaria leaf blight pathogens are seedborne, soilborne and airborne. The pathogens are greatly influenced by weather with the highest disease incidence reported in wet seasons and in areas with relatively high rainfall. The concentration of conidia, age of the host plants, and wetness period on leaves also influence the severity of the disease. This paper reviews the research and development of Alternaria blight in the oilseed brassicas (rapeseed-mustard) during the past years in relation to pathogen taxonomy, biology, epidemiology, host pathogen interaction and management through chemicals, botanicals, biological, cultural, and biotechnological approaches. The paper also attempts to present future outlook and strategy for Alternaria blight of rapeseed-mustard research.

Alternaria blight of is an important disease of Linseed (Linum usitatissimum L.) that hampers its productivity and oil content. During severe infections, spots coalesced and covered the large area of the leaves. Field experiments were conducted during 2015-16 and 2016-17 to evaluate the performance of promising lines/varieties of linseed against Alternaria blight disease. Microscopic examination of pathogens in diseased tissue reveled that Alternaria linicola Groves & Skolko and Alternaria lini Dey were two fungi associated with the spots on leaves and capsules. Studies of relative dominance of pathogens associated with the diseased tissue revealed the dominance of Alternaria linicola (95.86-98.63%) in comparison to Alternaria lini (1.31-4.14%) during different growth period of linseed crop. Sixty-three genotypes were evaluated against this disease under artificial epiphytotic condition to known the level of resistance and susceptibility in different genotypes under artificial inoculated conditions. Out of Sixty-three genotypes screened, 2 genotypes namely -LCK-152, LCK-7002, rated as resistant, under both the years. While 4 genotypes namely-BUAPUR LOCAL, CR-M-6X22-9, EC-9832, OLC-48 in 2015-16 and 3 genotypes in 2016-17 rated under highly susceptible lines against this disease.