Effect of ultra-drying on storability and vigour of onion seeds

Abstract

Onion seeds are poor storers they have one of the loweststorability among cultivated crops. Seed moisture is one ofthe critical factors which determines the seed storability.The effect of ultra-drying of onion seeds on seed storabilityand seed vigour was studied. Seeds of three onion varietiesBhima Dark Red, Bhima Shakti and Bhima Safed were driedin 2:1 beads to seed ratio (w/w) for 96 hours and packed andstored in moisture impervious pack for 12 months underambient conditions. The initial moisture of seeds was 8.46%- 5.25%, which reduced to 3.48 - 2.91% at after 96 hours. Theultra-dried seeds had higher seed viability and vigour incomparison to control (undried seeds). At the end of 12months of storage, the average seed germination in ultradriedseeds was 81% whereas in control it was 52%. Incomparison to control at the end of 12 months, the ultradriedseeds had 23.82%, 33.80%, 83.12% and 98.60% higherseedling length, seedling dry weight, vigour index-I andvigour index-II. The ultra-dried seeds also recorded lowerelectrical conductivity indicating lower membranedegradation during storage. Thus, drying of onion seed in2:1 beads to seed ratio for 96 hours is beneficial in enhancingthe storability of onion seeds.