International Journal of Plant & Soil Science

The present investigation was conducted from August 2025 to February 2026 at the Research Field, Department of Horticulture, Naini Agricultural Institute, Faculty of Agriculture (FoA), Sam Higginbottom University of Agriculture, Technology and Sciences (SHUATS), Prayagraj, Uttar Pradesh, India, to study the effects of plant growth regulators (PGRs) on flowering, fruit yield, and fruiting parameters in the meadow orchard of guava (Psidium guajava L.) cv. Allahabad Surkha. The experiment was laid out in a randomised block design (RBD) with three replications and 13 (12 + 1) treatments: T0, control (water spray); T1, chlormequat chloride (CCC) at 300 ppm; T2, CCC at 350 ppm; T3, CCC at 400 ppm; T4, GA₃ at 50 ppm; T5, GA₃ at 75 ppm; T6, GA₃ at 100 ppm; T7, triacontanol at 3 ppm; T8, triacontanol at 5 ppm; T9, triacontanol at 10 ppm; T10, NAA at 200 ppm; T11, NAA at 250 ppm; and T12, NAA at 300 ppm. Significant treatment differences were observed for flowering, fruit yield, and fruiting parameters.

The results showed that the foliar application of T5 (GA₃ at 75 ppm) produced the most favourable flowering responses, including the earliest flower initiation (34.17 days), the highest number of flower buds per tree (140.00), the highest flower-bud retention (72.90%), the shortest flowering duration (18.20 days), and the highest number of flowers per shoot (9.80). Treatment T8 (triacontanol at 5 ppm) produced the highest fruit set (55.39%), fruit retention (50.83%), fruit yield per tree (12.49 kg), and fruit yield per hectare (156.13 q ha⁻¹). It also recorded the greatest polar length (6.76 cm), radial diameter (6.41 cm), fruit weight (111.61 g), fruit volume (105.62 ml), flesh thickness (1.70 cm), and pulp weight (107.62 g), together with the lowest seed weight (4.00 g) and 100-seed weight (2.81 g).