Effect of Macronutrients and Gibberellic Acid on Photosynthetic Machinery, Nitrogen-Fixation, Cell Metabolites and Seed Yield of Chickpea (Cicer arietinum L.)

Abstract

An experiment was carried out with an aim to enhance the performance of chickpea by the spray of a small quantity of phosphorus (P) and/or sulphur (S) with or without the soaking of GA treatment (10-6 M GA for 8h) and/ or the GA spray treatment (10-6 M GA at 60-70 DAS). P and S each at 2kg/ha were sprayed in two equal splits i.e. half at 60 and the remaining half at the 70 DAS alone or in combination with the GA treatment. Prior to sowing, total seeds of chickpea were grouped into two; one group of seeds was soaked in 0M GA (control) and the other group were soaked in 10-6 M GA aqueous solution, each for 8 hours. There were total sixteen treatments with ten combinations of P and/or S with GA are possible viz., FPS, SGA + FP, SGA + FS, SGA + FPS, FGAP, FGAS, FGAPS, SGA + FGAP, SGA + FGAS and SGA+FGAPS. The combined application of P and S with GA showed better responses and further improvement in carbonic anhydrase (CA) activity, stomatal conductance (gs), net photosynthetic rate (PN), nitrate reductase activity (NR), and leghemoglobin content (Lb) at two sampling stages (90 and 100 DAS). This treatment also increased pod number per plant, seed yield per plant and harvest index (HI), seed protein and carbohydrate content at harvest. This combination augmented the protein content (21%), carbohydrate content (11%), seed yield (86%) and HI (91.78%).