Macronutrient requirement of groundnut: Effects on growth and yield components

A series of sand culture pot experiments were conducted to find out the optimum concentration of N, P, K, Ca, and S, in the nutrient solution, for growing groundnut with maximum growth and yield by taking each macronutrient in the range of 2–200 ppm. The observations on plant height, dry matter production, and podding at 20, 40, 60 days after emergence (DAE) and at harvest, chlorophyll content and transpiration at 40 and 70 DAE, flowering from 25–70 DAE and finally pod and haulm yields, at harvest showed that increasing the macronutrients levels, in the nutrients solution, increased these parameters significantly up to a certain level only which was optimum dose for that parameter. The number of flowers produced during the first two weeks (25–40 DAE) of its flowering increased significantly up to 10 ppm of N, P, K, and S and 20 ppm of Ca, but the number of pods at harvest increased up to 50 ppm of N and 20 ppm of P, K, Ca and S. The pod yield and dry matter, chlorophyll, flowering, podding and transpiration at either of the stages, however, increased up to 20 ppm of P and S and 50 ppm of N, K, and Ca and further increase in the levels of these macro-nutrients did not increase these parameters any more significantly. The macronutrient levels of 50 ppm of N, K, and Ca, and 20 ppm of P and S, in nutrient solution, are being recommended for growing groundnut in nutrient culture.