Sequential ethephon application coordinates floral sex expression and fruit yield in bottle gourd ( Lagenaria siceraria L.)

A field experiment was conducted during the Kharif seasons of 2022 and 2023 at Punjab Agricultural University, Regional Research Station, Abohar, to evaluate the effects of foliar ethephon application (200 ppm) at different growth stages on growth, flowering, yield, and quality of bottle gourd. Six treatments, comprising sprays at the two-leaf stage, four-leaf stage, bud initiation stage, their combinations and an untreated control, were arranged in a randomized block design with four replications. Combined application at the two-leaf and four-leaf + bud initiation stage (T5) proved most effective, producing the maximum number of branches, earliest female flower appearance, delayed male flower initiation, lowest male flower count and highest female flower count. Treatment T5 also recorded maximum polar diameter (15.63 cm), equatorial diameter (13.84 cm), fruit weight (564.17 g) and fruits per vine (7.71). Pooled fruit yield under T5 was 10.4% higher than the best single-stage application, with improved total fruit yield (39.03 kg/plot), productivity (52.05 t ha−1) and TSS (2.56 °Brix). Therefore, foliar ethephon application at 200 ppm at three critical growth stages improved growth, reproductive performance and productivity in bottle gourd . Further validation across diverse environments, cultivars and production systems is needed to confirm its broader applicability.