Abstract

The role of Alternaria sp on seed vigor of rapeseed, Brassica napus, was investigated. Seed samples were collected from rapeseed growing regions of Sindh province. The samples were processed for fungal recovery using blotter paper and agar plate methods. Both methods produced a number of parasitic and saprophytic fungi. Among the recovered fungi, Alternaria sp was predominant with 16% average infection. Similarly, effect of seed treatment with Topsin M. was examined in this experiment. It improved seed health significantly over inoculated seeds. The treated seeds showed greater germination (16.15%) with 83.69% more healthy seedling in comparison with inoculated seeds. Root and shoot systems were significantly improved in seedlings from treated seed compared to those from inoculated seeds. The results of this study suggest grading seed samples to reduce seed impurities and seed treatment (particularly with Topsin M) to eliminate seed borne pathogen, especially Alternaria from rapeseed to enhance production by the growers.

Key words: Seed health, seed borne fungi, Alternaria, seed treatment.