EFFECT OF PHOSPHORUS AND GIBBERELLIC ACID ON GROWTH AND YIELD OF TUBEROSE

Abstract

The present study was carried out in the Horticulture Farm of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during August 2017 to October 2018 to study the effect of phosphorus and gibberellic acid on growth and yield of tuberose (Polianthes tuberosa). Four phosphorus levels viz P ii 0 = 0 kg P 2 O 5 ha -1 , P

ha -1 , P 2 = 85 kg P 2 O 5 ha -1 and P 3 = 110 kg P 2 O 5 ha -1 and three GA 3 1 = 65 kg P levels viz. G = 0 ppm GA 3 , G 1 = 115 ppm GA 3 and G 2 =145 ppm GA were treated. The experiment was laid out in the two factors Randomized Complete Block Design (RCBD) with three replications. Regarding P application, P 3 3 (110 kg P 2 O 5 ha -1 ) gave the highest plant height (61.02 cm) and number of leaves plant -1 (7. 29.35) compared to control treatment but the highest yield parameters number of spike ha -1 (368.60 thousand), bulb yield (25.88 t ha -1 ) and bulblet yield (14.21 t ha -1 ) were found from the treatment P 2 (85 kg P 2 O 5 ha -1 ) whereas control treatment P 0 (0 kg P 2 O 5 ha -1 ) showed lowest results. In case of GA 3 application, G 2 (145 ppm GA ) showed highest growth and yield parameter and the highest number of spike ha -1 3 (362.30 thousand), bulb yield (25.38 t ha -1 ) and bulblet yield (14.00 t ha -1 ) were obtained from G ) whereas the lowest results were found from the control treatment G 2 ). Treatment combination of P and GA 3 , the highest number of spike ha (405.60 thousand), bulb yield (31.45 t ha -1 ), and bulblet yield (16.01 t ha -1 ) were found from P 2 G 2 combination whereas the lowest number of spike ha -1 (189.60 thousand), bulb yield (14.57 t ha -1 ) and bulblet yield (9.05 t ha -1 ) was found from the control treatment combination of P 0 G . In terms of economic analysis, the highest gross return (Tk. 471550), net return (Tk. 289337) and BCR (2.59) were also obtained from P 0 (85 kg P 2 O 5 ha -1 with 145 ppm GA ) whereas the lowest gross return (Tk. 227470), net return (Tk. 57703) and BCR (1.34) was obtained from P 3 0 G 0 0 (145 ppm GA 0 (0 ppm GA (no P and GA ). From the above results, it can be stated that that the P application @ 85 kg P 2 application @ 145 ppm can be considered for higher yield and economic return in commercial cultivation of tuberose.