Amelioration of water deficit by application of potassium and FYM in Lens culinaris (L.) Medikus and Brassica napus L. under intercropping system

Abstract

Lens culinaris is an annual edible legume while Brassica napus is a common oil-production crop. One of the most frequent abiotic stresses endangering agricultural food crops is drought. Drought significantly impairs crop plants’ physiology and productivity which eventually results in plant death. The present research was done to ameliorate the adverse effects of drought stress on the growth, photosynthetic pigments and water status of Brassica napus L. (GSC-7 variety) and Lens culinaris (L.) Medikus (HM-1 variety) intercropping by combined application of potassium and farm yard manure (FYM). The treatments were given as control (2 irrigations), early irrigation (irrigation only during vegetative stage), late irrigation (irrigation only during flowering stage) and stress (0 irrigation) along with different concentrations of potassium and FYM i.e. K0(control) K1(10kg/acre) and K2(20kg/acre) K1M (10kg/acre+10tonne/hectare) and K2M (20kg/acre+10tonne/hectare. At the vegetative stage (45DAS), samples were taken and analyzed for different attributes. Drought stress significantly affected the morphology and physiology of both cultivars by reducing the photosynthetic pigments, water status (relative water content [RWC] and membrane stability index [MSI]) in both cultivars compared to the control. But potassium(K) and FYM supplementation improved both cultivars' RWC, MSI, photosynthetic pigments and growth parameters. In addition, after K and FYM application under drought stress, MDA levels and electrolyte leakage were decreased. These results authenticate that potassium in combination with FYM considerably reduces the effect of drought on both cultivars of intercropping by enhancing the plants' growth, photosynthetic activities and water status.