Effect of Foliar Application of Growth Regulators on Growth and Yield of Onion (Allium cepa)

A field experiment was conducted at Horticulture Farm of Agriculture and Forestry University, Rampur, Chitwan, Nepal from 1 December to30 April of 2018/19 to evaluate the effect of plant growth regulators on onion (Allium cepa cv. Nasik-53). The experiment was laid out in a Randomized Complete Block Design (RCBD) with 13 treatments. Growth regulators including: GA3 and NAA each at 75, 150 and 200 mg L-1 concentrations together with the combined forms were applied at 3 and 7 leaf stages of onion crop and the obtained data were compared with the control (distilled water spray) plants. Each treatment was replicated three times. The application of combination of 150 mg L-1 NAA at 3 leaf stage and 150 mg L-1 GA3 at 7 leaf stage resulted in highest values for plant height (76.67 cm), number of leaves (11.33), stem diameter (2.19 cm), bulb diameter (7.55 cm) and fresh weight (72.66 gm) while the control treatment resulted in the lowest values for all these attributes. Therefore, the combined application of 150 mg L-1 of NAA at 3-leaf stage and 150 mg L-1 of GA3 at 7 leaf stage can be recommended to enhance the growth and yield of onion.