INFLUENCE OF SEED TREATMENT ON FIELD PERFORMANCE AND STORABILITY OF ACCELERATED AGED SEED OF SORGHUM
Acharya N G Ranga Agricultural University, Guntur
The present investigation was carried out in the Department of Seed Science and Technology, Advanced Post Graduate Centre, Lam, Guntur and Agricultural Research Station (ARS), Jangamaheswarapuram, Guntur during 2017-18 to study the impact of accelerated ageing on seed quality and storability and influence of seed treatment on initial seed quality, field performance of accelerated aged seed of sorghum variety NTJ -4. Initially freshly harvested (Rabi, 2017-18) seed of sorghum was subjected to accelerated ageing for 24, 36, 48 and 60 h. The standard germination and seed quality parameters of accelerated aged seeds were tested along with control (unaged seed). The accelerated ageing exhibited significant decrease in all seed quality parameters viz., germination, seedling length, seedling vigour index and field emergence. The electrical conductivity of seed leachates increased with the duration of accelerated ageing. Maximum per cent decline in germination (8%), seedling length (27.17%) seedling vigour index (33.03%) and field emergence (12%) over the control was noticed with 60 h accelerated ageing. The seed samples with different levels of germination and seedling vigour thus generated by different durations of accelerated ageing along with the control were kept for storage in cloth bags under ambient conditions. The germination and seed quality parameters were tested at monthly interval. The germination and seed quality parameters gradually decreased, while the electrical conductivity of seed leachates increased due to accelerated ageing and period of storage. The result indicated that 24 h, 36 h, 48 h and 60 h were used to predict the seed quality parameters of normal (unaged) seed of sorghum variety NTJ-4 stored for 1 to 3 months, 3-5 months, 4-8 months and 68 months of respectively xiii The accelerated aged seed was subjected to seed invigoration with 50 ppm GA3, 2% KH2PO4, 2% CaCl2 and 2% KNO3 for 10 h duration. The initial seed quality and field performance of the invigorated accelerated aged seed along with untreated accelerated aged was assessed. Results revealed that the duration of accelerated ageing caused a significant reduction in all the seed quality parameters except electrical conductivity of seed leachates, crop growth, yield and its contributing characters. But electrical conductivity of seed leachates and duration of flowering and maturity increased with increasing duration of accelerated ageing. Seed priming with different chemicals showed significant improvement in seed quality, crop growth, field performance and yield. The interaction effect between accelerated ageing and seed treatment had non-significant influence on all the seed quality and field parameters except germination and field emergence. Among the treatments seed priming with different chemicals, 2% KH2PO4 and 2% CaCl2 showed highest improvement in germination, seedling length, seedling vigour index and field emergence and decline in electrical conductivity of seed leachates. In field studies also the accelerated aged seed treated with 2% KH2PO4 and 2% CaCl2 recorded significantly highest plant height at 60 DAS and at maturity, earhead weight, earhead length, earhead width, number of seeds per head, single plant yield and 1000 seed weight along with lesser duration of 50% flowering and maturity. The seed quality studies from the harvested crop indicated that duration of accelerated ageing and seed treatment with different chemicals showed significant but marginal difference in germination, seedling length and seedling vigour index. However, the interaction between duration of accelerated ageing and seed treatment was non-significant. The present study proved that accelerated ageing test can be used to predict the storability of sorghum seed. Significant enhancement in seed quality is possible through seed priming of aged seed of sorghum with either 2% KH2PO4 or 2 % CaCl2.