Mitigating the effects of elevated temperature through the use of growth regulators in bell pepper

Abstract

High temperature adversely affects the production of bell pepper (Capsicum annuum L.) especially under North Indian plains where the temperature is above 40°C during summers. The present investigation was conducted to evaluate the effect of exogenous application of growth regulators viz. salicylic acid (SA) and 24-epibrassinolide (EBR) on growth, physiology and yield parameters in bell pepper cv Indra. Foliar application of SA (0.1, 0.20 and 0.50 mM) and EBR (0.05, 0.10 and 0.20 pM) was done at 30 days after transplantation (DAT) (vegetative stage), 60 DAT (reproductive stage) and 90 DAT (post reproductive stage). All the concentrations of both growth regulators i.e. SA and EBR were effective in imparting thermotolerance in terms of improved growth parameters (plant height, plant spread and leaf area), photosynthetic efficiency, membrane thermostability, increased pollen viability and fruit set at high temperature ultimately resulting in improved yield. However, foliar application of SA (0.20 mM) and EBR (0.10 pM) at 60 DAT resulted in significant enhancement in growth and yield parameters as compared to untreated control.