Effect of Plant Growth Regulators on Fruit-set and Quality of Guava

Two plant growth regulators: β-NOA (50 and 80 ppm) and GA (200 and 250 ppm) were applied to emasculated flowers at anthesis to set parthenocarpic fruit, while in the control treatment fruit set was achieved by natural pollination. The application of β-NOA found ineffective in setting parthenocarpic guava. No significant differences were observed in the length and diameter of fruit between parthenocarpic and naturally pollinated seeded fruit at different days after anthesis. The mean fruit weight, TSS and ascorbic acid content of parthenocarpic fruit were similar to that of seeded fruit. Significant higher amount of total polyphenol was detected in the seeded fruit than the parthenocarpic fruit. Although 200 ppm GA showed comparatively better response to fruit growth, TSS and ascorbic acid content than 250 ppm GA but not in a statistical level.