EFFECT OF DISCOLOURATION ON SEED QUALITY IN CLUSTERBEAN ( CYAMOPSIS TETRAGONOLOBA ( L . ) TAUB . )

The experiment was conducted on clusterbean variety HG 2-20 during kharif 2016 to know the effect of discolouration on seed quality parameters. On the basis of visual discolouration, the collected seed was divided into five different categories viz., no discolouration, 0-15 per cent, 16-50 per cent, 51100 per cent discolouration and shrivelled seeds. The results revealed that significant variation was observed among all the seed lots in all the seed quality parameters. Maximum germination (59.67%) was observed in the seed lot without discolouration but it was also below the Indian minimum seed certification standards (75%), while it was observed minimum in the shrivelled seed (8.33%). Maximum seedling length (28.10 cm), seedling dry weight (0.145 mg), vigour index-I (1676.73) and vigour index-II (8.63) were also recorded in the healthy seeds (No discolouration). In shrivelled seeds, minimum seedling length (12.60 cm), seedling dry weight (0.058 mg), vigour index-I (104.23) and vigour index-II (0.45) were recorded. Six funginamely Alternaria cyamopsidis, Aspergillus spp.,Curvularia lunat, Fusarium spp., Helminthosporium spp. Cercospora spp. were detected but no bacterial infection was observed in the discoloured seeds.