Growth and physiological performance of grape cv. ManikChaman as affected by berry thinning, plant growth regulators and micronutrients

Abstract

The seedless grape variety ManikChaman is an important cultivar in India, valued for its bold berry size and superior fruit quality, making it suitable for both domestic and export market. Despite its growing popularity, fruit quality from this region remains suboptimal. To address this issue, a study was conducted to examine the influence of berry thinning and the application of growth regulators and micronutrients on growth, yield and quality of ManikChaman grapes. The experiment included two factors: varying levels of berry thinning treatments and different treatment combinations involving plant growth regulators and micronutrients. Findings revealed that berry thinning was negatively correlated with vegetative growth and physiological characters. The growth regulators and micronutrients combination showed positiveresponce. The most effective treatment was combined application of GA₃ (150 ppm), a micronutrient mixture consisting of ZnSO₄ at 3 g/L,FeSO₄ at 2 g/L, MnSO₄ at 2 g/L and boric acid at 1 g/L, along with CPPU (2 ppm) and brassinosteroids (0.5 and 1.0 ppm) at different growth stages.