Repercussion of photosynthetic variables and related enzymes under influence of sodium dihydrogen orthophosphate and sodium sulphate with two modes of gibberellic acid application

An experiment was carried out to investigate whether the application of gibberellic acid (GA) along with NaH₂PO₄ and/or Na₂SO₄ could ameliorate photosynthetic variables and enzymes in chickpea cultivar DCP 92-3 without compromising the nitrogen fixing activity. Before, sowing the seeds of chickpea were soaked for 8 h in 10⁻⁶MGA. 60 and 70 days after sowing (DAS), the plants were sprayed with 10⁻⁶MGA along with 2 kg P and/or S/ha in two equal splits. Performance of the crop was assessed in terms of chlorophyll content (Chl), net photosynthetic rate (P_N), stomatal conductance (gs), carbonic anhydrase activity (C A) and one most significant N-fixing enzyme, NR. Treatment (16) S_GA+F_GAPS proved best, it enhanced Chl content by 46.16% and 48.84% P_N by 64.24 and 65.37%, NR by 22.37% and 22.46% respectively at 90 and 100 DAS. CA at 100 DAS only and gs at both stages of sampling found non-significant. Moreover, CA enhanced by 64.56% at 90 DAS also.