Influence of gibberellic acid on the growth and yield of bitter gourd in semi-arid climate

Bitter gourd (Momordica charantia L.) is an important cucurbitaceous vegetable due to its high nutritional value. Different growth regulators were used for the better yield of bitter gourd but the application of gibberellic acid as foliar spray is less addressed. An experiment was conducted to investigate the effect of gibberellic acid (GA3) on the yield and growth stages of bitter gourd at Horticulture Research Farm, The University of Agriculture Peshawar, Pakistan during summer 2016. Gibberellic acid concentrations (GA3) 0 ppm, 30 ppm, 60 ppm, and 90 ppm were applied at different leaf stages i.e., 2-4 leaves, 5-7 leaves, and 8-10 leaves. Results revealed that both the growth and yield were significantly influenced by the application of GA3 concentrations at different growth stages. Furthermore, the use of 90 ppm GA3 concentration improved the minimum male to female ratio (2.19), maximum number of fruits plant-1 (20.22), fruit length (15.64 cm), fruit diameter (3.51 cm), fruit weight plant-1 (137.82 g), fruit yield kg plot-1 (13.98 kg), and total yield tons ha-1 (38.83 t) respectively. While 30 ppm GA3 improved the minimum days to first flower (31.22) and minimum days to first harvest (48.56). However, regarding the growth stages 8-10 leaf stage improved minimum days to first flower (33.33), minimum days to first harvest (50.33), minimum male to female ratio (2.81), and maximum number of fruits plant-1 (18.50), number of branches plant-1(4.67), fruit length (15.00 cm), fruit diameter (3.29 cm), fruit weight plant-1 (137.19 g), fruit yield kg plot-1 (12.79 kg), and total yield tons ha-1 (35.53 t). Overall gibberellic acid at 90 ppm concentration at 8-10 leaf stages was found beneficial for better growth and yield of bitter gourd under the semi-arid climatic condition of Peshawar.