SEED HEALTH AND QUALITY STATUS OF MUSTARD SEED

Abstract

uality and health status of nine improved varieties of breeder seed and farmer seed of mustard variety Tori-7 grown in 2007-2008 was determined by seed health and quality analysis in the Seed Health Laboratory, Department of Plant Pathology, SAU, Dhaka. Respectively, 14 seed samples of breeder tier and 40 from farmers representing four districts of Bangladesh were included in the present study. Quality analysis showed that the average moisture content of breeder seed was 6.9%. and 5.6% collected from BARI, Gazipur and RARS, Ishurdi, respectively; whereas in fanner seed, the average moisture content was 8.0010.Three types of seed contaminants viz. inert matter, other crop seed and varietal mixture were recorded in fanner seed; while in breeder seed only inert matter was observed. Five types of abnormal seeds viz. discolored seed, shriveled seed, spotted seed, undersized seed and broken seed were encountered in farmer seed; whereas four types of abnormal seed except broken seed were found in breeder seed. The amount of abnormal seed and seed contaminants were higher in farmer seed than breeder seed. In an average, 93 and 60% 'best' or 'clean' seed were recovered from breeder and fanner seed, respectively by removing the seed contaminants and abnormal seed through manual seed cleaning. Occurrence of seed contaminants and abnormal seed was always higher in farmer seed compared to breeder seed. Seed health analysis revealed that 11 fungi were associated with mustard seeds. Of those, five fungi viz. Alternaria brassicae, A. brassicicola, Fusarium solani, Aspergillus flavus and Penicillium sp. were predominant, constituting 87.5% of the total seed-borne fungal infections. The fungi varied in prevalence with respect to seed tier, variety and sources of seed collection. Prevalence of • the total as well as the individual predominant fungi were found always higher in unclean seed in comparison to clean seed at all the locations. Occurrence of the predominant fungi was higher in farmer seed compare to breeder seed. •Clean , seed significantly gave higher percentage of normal seedlings and lesser number of abnormal seedlings and dead seeds over unclean seed both in breeder and fanner seed. Health and quality of fanner seed of mustard can be improved through manual seed cleaning.