Growth, Water Relations And Chlorophyll Enhancement By Potassium Application In Intercropping System Of Gossypium Hirsutum L. And Cajanus Cajan (L.) Millsp. Under Different Irrigation Regimes

Abstract

Introduction:  Plant encounters various biotic and abiotic stress throughout their life cycle. Among abiotic stress, drought stress decreases growth and photosynthetic rate in crop plants which in turn decreases overall yield of food crops.

Methods: The present study investigated the impact of potassium on plant height, fresh and dry weight of plant, leaf area, leaf area index, relative water content, membrane stability index, electrolyte leakage and photosynthetic pigments in intercropping system of Gossypium hirsutum L. (RCH-773 variety) and Cajanus cajan (L.) Millsp. (Manak variety). The treatments were as given i.e. control (full irrigation), early water stress (no irrigation at vegetative stage), late water stress (no irrigation at flowering stage) and stress (no irrigation) along with three potassium concentration K₀, K₁, K₂ (0, 20, 60 kg/acre respectively).The sampling was done at vegetative stage (40 days after sowing).

Results: A long progressive water stress significantly reduced plant height, fresh and dry weight, leaf area, leaf area index, relative water content, membrane stability index and photosynthetic pigments. But potassium fertilizer enhanced all these parameters at a par value. The other parameter i.e. electrolyte leakage was increased in stress conditions. But after potassium application, electrolyte leakage showed a remarkable decrease in control as well as water stressed plants.

Conclusion: The findings of present study clearly shows that potassium alleviates the negative impact of drought stress. It means potassium is a strong osmo-regulator, maintains cation-anion balance and helps plant withstanding drought stress conditions.