The present investigation was conducted to evaluate the effect of ethephon on sex expression, growth and seed yield in bitter gourd. A field experiment was carried out during 2022 and 2023 at the Research Farm, Department of Seed Science and Technology, Dr Y S Parmar University of Horticulture and Forestry, Nauni, Solan, Himachal Pradesh. The experiment comprised six ethephon concentrations (50, 100, 150, 200, 250 and 300 ppm) and three stages of application S1: 4 true leaf stage; S2: 4 true leaf stage+ 15 days after first spray; S3: 4 true leaf stage + 15 days after first spray + 15 days after second spray, resulting in 18 treatment combinations, along with a control (no ethephon). The treatment E6S3 (300 ppm at three stages) proved most effective by promoting femaleness and improving seed yield attributes, recorded maximum fruit set (%), the highest number of fruits per plant and maximum seed yield per plot and per hectare, along with earlier female flower appearance and delayed male flower appearance. Overall, repeated application of ethephon at 300 ppm at the 4 true leaf stage and at 15-day intervals was found most suitable for enhancing female flower production, fruit efficiency and seed yield in bitter gourd under mid-hill conditions of Himachal Pradesh.
Shivani et al. (Tue,) studied this question.