Effect of Gamma irradiation on seed quality, insect infestation and fungal infection in Sorghum (Sorghum bicolor L. Moench)

Influence of five gamma radiation doses generated from Co⁶⁰ source of Gamma chamber 5000 in combination with control on seed quality parameters of sorghum parents line and variety C43, CSH14 and CSV 29 was studied. Seed quality parameters viz., germination percentage, field emergence, speed of germination, peak value of germination and coefficient of velocity of germination, root, shoot, seedling length, vigour index, electrical conductivity, seed moisture and seed health were evaluated immediately after irradiation and up to nine months under storage at ambient conditions. The experiment was laid out in a Completely Randomised Design with factorial concept. Marked significance of interaction effects was recorded for various seed quality parameters studied immediately after exposing the seed to selected doses of gamma rays. The results indicated that gamma doses up to 2000 Gy were found to exercise positive influence in enhancing all the germination, seedling and biochemical parameters. However, this gamma radiation differed significantly in their response registered variable values for seed quality parameters. The doses beyond 2000 Gy had detrimental effect by interfering with various seed quality attributes. The analysis of bimonthly data at four intervals on seed storage potential up to nine months indicated significant influence of storage period on all the seed quality parameters including seed health However, The results also indicated that among germination and seedling traits studied, peak value of germination, vigour index and root length were the most sensitive seed quality parameters affected by ageing due to storage under ambient conditions. The study revealed that, combinations viz., control/200, 600 Gy, Glutathione/200, 400 Gy and Zinc oxide/800 Gy performed better for various germination, seedling, biochemical, seed moisture and seed health parameters (weevil infestation) evaluated during storage.