Effect of Plant Growth Regulators on Growth, Yield and Quality Parameter of Guava (Psidium guajava L.)

Abstract

Guava (Psidium guajava L.) is an important fruit crop, but poor management of flowering, fruit development, fruit retention and fruit quality may restrict its production and economic benefits. The present investigation was undertaken during 2025–26 at the Experimental Farm of Suresh Gyan Vihar University, Jaipur, Rajasthan, to study the influence of several plant growth regulators on flowering, yield and quality attributes of guava cv. Allahabad Safeda. The experiment was laid out in a randomised block design with three replications and nine treatments consisting of naphthalene acetic acid at 20 and 40 ppm, gibberellic acid at 50 and 100 ppm, CPPU at 5 and 10 ppm, salicylic acid at 100 and 200 ppm, and a water-spray control. Results showed considerable variation among treatments for flowering, fruit set, fruit retention, yield attributes and fruit quality. The application of gibberellic acid at 100 ppm recorded the highest number of flowers per shoot (7.30), fruit set (73.00 per cent), fruit retention (70.67 per cent), number of fruits per plant (100.00), average fruit weight (209.00 g), fruit yield (39.20 kg plant⁻¹ and 58.30 quintals ha⁻¹) and pulp-to-seed ratio (5.50), and also hastened flowering (31.33 days). Maximum total soluble solids (13.80 °Brix), ascorbic acid (287.43 mg 100 g⁻¹), total sugars (10.75 per cent), reducing sugars (6.25 per cent) and non-reducing sugars (4.50 per cent) were recorded in the same treatment. The minimum titratable acidity (0.25 per cent) was also recorded in this treatment. For several characteristics, the control treatment showed numerically lower values for the main yield and quality traits. The findings indicated that treatment with gibberellic acid at 100 ppm improved flowering, fruit development, yield and important qualitative characteristics of guava under the agro-climatic conditions of Jaipur, Rajasthan.