Effect of plant growth regulators on the performance of lady’s finger (Abelmoschus esculentus L.)

Abstract

Field experiments were conducted at the Plant Physiology Field of Horticulture Research Centre (HRC) of Bangladesh Agricultural Research Institute (BARI), Gazipur during the summer seasons of 2022 and 2023 to study the effect of plant growth regulators (PGRs) on the growth and yield of lady’s finger. Two okra varieties, namely BARI Dheros-2 and OK-1820 were sprayed with seven PGRs treatments viz., two levels (100 and 200 ppm) of naphthalene acetic acid (NAA), two levels (100 and 200 ppm) gibberellic acid (GA3) and two levels (200 and 400 ppm) of chlorocholine chloride (CCC) concentrations at 4 weeks after seed sowing, first flowering and 3 weeks after first flowering stages. The control plots were treated with tap water. The experiment was conducted in a split-plot design with three replications allocating varieties in main plot and PGR treatments in sub plots. The plant height, leaf area index (LAI), dry weight/plant, fruit length, fruit diameter, individual fruit weight, number of fruits/plant and weight of fruits/plant were the maximum for 100 ppm GA3 followed by 200 ppm GA3 in both BARI Dheros-2 and OK-1820 in two years. The highest fruit yield per hectare (21.10 t in BARI Dheros-2 and 21.74 t in OK-1820 during 2022, and 29.11 t/ha in BARI Dheros-2 and 29.22 t/ha in OK-1820 during 2023) was recorded with the application of 100 ppm GA3 which was followed by 200 ppm GA3 (19.88 t/ha in BARI Dheros-2 and 20.87 t/ha in OK-1820 during 2022, and 28.37 t/ha in BARI Dheros-2 and 28.75 t/ha during 2023) and 400 ppm CCC (27.03 t/ha in BARI Dheros-2 and 26.88 t/ha in OK-1820 during 2023). The BARI Dheros-2, recorded the maximum average fruit yield for 100 ppm GA3 (25.11 t/ha) followed by 200 ppm GA3 (24.13 t/ha) and 400 ppm CCC (21.34 t/ha) while in OK-1820, 25.48, 24.81 and 23.25 t/ha average fruit yield were found in 100 ppm GA3, 200 ppm GA3 and 400 ppm CCC, respectively. Both the varieties provided with the maximum gross margin while treated with GA3 @ 100 ppm (Tk. 4, 52,237/ha from BARI Dheros-2 and Tk. 4, 61,612/ha from OK-1820). The highest BCR (3.94) was recorded for CCC @400 ppm in OK-1820 and BCR 3.62, 3.67 and 3.58 were for 400 ppm CCC, 200 ppm CCC and 100 ppm GA3 from BARI Dheros-2, respectively. It might be recommended that spraying of 400 ppm CCC or 100 ppm GA3 singly in 3 equal sprays at 4 weeks after sowing, at flowering and 3 weeks after first flowering would be optimum for maximum fruit yield and highest return of lady’s finger.

Bangladesh J. Agril. Res. 49(4): 349-361, December 2024