Physiological investigations on interactive effect of P and K on growth and yield of chickpea

A field experiment was conducted to study the individual and combined effect of phosphorus and potassium on morphophysiological traits and yield of chickpea (Cicer arietinum L.) cv. Pusa 417. The observations were recorded on branch number, shoot dry weight, root dry weight and nodule number/plant, nitrogenase activity of nodules, leaf area index, crop growth rate and net assimilation rate. At maturity pod number, 100 seed weight, seed yield and seed yield merit were recorded. A combination of 40 kg P₂O₅ and 20 kg K₂O/ha produced maximum yield. The low input of P₂O₅ was compensated by high input of K₂O and vice versa. At lower phosphorus levels (0 or 20 kg P₂O₅/ha) the requirement of potassium was high (40 kg K₂O/ha). However, at higher level of phosphorus (40 or 60 kg P₂O₅/ha) the application of only 20 kg K₂O/ha proved effective. Seed yield and seed yield merit were enhanced by 82 and 85% by 40 kg P₂O₅ × 20 kg K₂O over control.