EFFECT OF IAA AND GA3 ON THE GROWTH, CURD FORMA TIO AND YIELD OF CAULIFLOWER

Abstract

An experiment was carried out at the Horticultural farm, Sher-e-Bangla Agricultural University, Sher-e-Bangla agar, Dhaka-1207 during October 2006 through January 2007 with two growth regulators, Gibberellic Acid (GA3) and lndole Acetic Acid (IAA) applied at two different stages namely vegetative stage and curd formation stage to observe the growth, curd size and yield contributing characters of the modem HYV cauliflower cultivar, 'Shirajuki'. The experiment was laid out in a Randomized Complete Block Design (RCBD). The field experiment had three replications. There were three concentrations of IAA (0, 5, 10 ppm) and GA3 (0, 80, 100 ppm). Application of IAA 10 ppm resulted the minimum (47.76) days from transplanting to curd initiation and the maximum (34.40 cm) plant height was at harvest while the minimum (28.86 cm) was recorded from control treatment. The maximum number of leaves per plant (25.04). length of the largest leaf (50. 77 cm). breadth of the largest leaf ( 18.20 cm) at harvest, curd diameter at harvest (23.38 cm) were recorded from IAA 5 ppm (11) whereas, the minimum was recorded from control treatment. Application of GA3 100 ppm (G2) resulted the highest pure curd height ( 14.59 cm), curd weight with leaves ( 1.90 kg) at harvest, marketable curd weight (1.33 kg /plant) and curd yield (53.33 t/ha) while the lowest was recorded from control treatment. The maximum benefit cost ratio (BCR) (2.93) was recorded from the treatment combination of I2G2 while the minimum (1.18) was recorded from control treatment. So, IAA 10 ppm and GA3 l 00 ppm indicating the economic viability of using growth regulator in curd growth and yield of cauliflower.