Phosphorus ameliorates crop productivity,photosynthesis, nitrate reductase activity and nutrient accumulation in coffee senna (Senna occidentalis L.) under phosphorus-deficient soil

Abstract

Coffee senna (Senna occidentalis L.) plants were subjected to five phosphorus levels: 0, 25, 50, 75 and 100 mg P per kg soil (P₀, P₁, P₂, P₃ and P₄, respectively). A pot culture experiment was conducted in a net house, AMU, Aligarh, India, under phosphorus-deficient soil. The present data indicates that soil-applied phosphorus significantly ameliorates most of the attributes studied. Out of five phosphorus levels, 75 mg P per kg soil (P₃) proved best and enhanced fresh and dry weights, total chlorophyll and carotenoid content, nitrate reductase activity and leaf-NPK and Ca content, analyzed at 120, 270 and 300 days after sowing (DAS). The number of pods, seed-yield per plant and seed-protein content (330 DAS) were significantly enhanced by the P₃ level, except the number of seeds per pod, 100-seed weight and total anthraquinone glycosides content, respectively. Transpiration rate, stomatal conductance and net photosynthetic rate were also enhanced by this treatment.