THE IMPACT OF GIBERELLIC ACID AND DIFFERENT DECAPITATION METHODS ON SEED YIELD OF BROCCOLI

The present investigation was conducted during the rabi season of 2021-22 and 2022-23 in the Experimental farm, Department of Horticulture, College of Agriculture, Assam Agricultural University, Jorhat.The experiment was laid out in a Randomized Block Design (factorial) with three replications.The sixteen treatments comprised combinations of four different concentrations of GA 3 viz., G 0 (0 ppm), G 1 (25 ppm), G 2 (50 ppm) and G 3 (75 ppm) and four different head decapitation methods viz., D 1 (decapitation of the primary head at appearance), D 2 (decapitation of the primary head at the marketable stage), D 3 (decapitation of the secondary heads at appearance) and D 0 (control).Among GA 3 treatments, GA 3 @50ppm GA 3 was applied as seedling root dip treatment for 24 hours before transplanting was found to be the best in producing highest seed yield per plant (4.24 g/plant) and seed yield per hectare (1.59 q/ha).While among different decapitation methods, D 1 (Decapitation of primary head at appearance resulted the highest seed yield per plant (4.19 g) and seed yield per hectare (1.98 q ha -1 ).Therefore, it is suggested that decapitation of the primary head at appearance (D 1 ) can be recommended for commercial seed production of broccoli.Moreover, the interaction effect of G 2 D 1 (GA 3 @50 ppm and decapitation of the primary heads at appearance) recorded highest seed yield per plant (5.42 g) and seed yield per hectare (235.49kg).Therefore, it can be concluded that root dip treatment of broccoli seedlings with 50ppm GA 3 and with decapitation of broccoli head at appearance was found to be the best for producing highest seed yield of broccoli.