VERNALIZATION AND GIBBERELLIC ACID RESPONSE IN SUMMER ONION’S (ALLIUM CEPA L.) REPRODUCTIVE PHASES

The present study was aimed at determining the effect of vernalization and Gibberellic Acid (GA3) on seed yield and quality of summer onion. There were three vernalization treatments viz., no vernalization (control), vernalization at 5°C for 14 days and vernalization at 10°C for 14 days and four GA3 treatment viz., 0, 50, 100 and 150 ppm. The two-factor experiment was laid out in the Randomized Complete Block Design with three replications. The results of the experiment showed that the vernalization and GA3 had significant influence on all the parameters studied. Solitary Effect of vernalization and GA3 was significant on the parameters such as plant height, number of leaves plant-1, the highest number of flowering stalk, number of umbels plant-1, number of bud umbel-1, percent flowering at 45 and 60 DAP, number of seeds umbel-1, weight of seeds umbel- 1, weight of seeds plant-1, weight of seeds plot-1, 1000 seed weight, seed yield, number of fruits umbel-1, percent of fruit set umbel-1and percent germination. The highest seed yield (248.16 kg ha-1) was obtained from vernalization at 5°C for 14 days. The lowest values of all the parameters were recorded at control treatment. The highest seed yield (191.77 kgha-1) was obtained from 100 ppm GA3. The lowest values of all the parameters were recorded in the 0 ppm GA3 treatment. Use of suitable vernalization of mother bulb and proper concentration of gibberellic acid can be a possible way to expand onion production at the time of summer.