Precursor-inoculum interaction for the growth promotion of cotton under field conditions

The present experiment was conducted during 2019-2021 at Agricultural Biotechnology Research Institute, Ayub Agricultural Research Institute, Faisalabad, Pakistan. The yield of local BT cotton variety FH-142 was evaluated using different combinations of rhizobacteria (free living diazotroph and phosphate solubilizer) with auxin precursor L-tryptophan (L-TRP). The experiment was comprised of seven treatments under Randomized Complete Block Design (RCBD) replicated thrice. The experiment was repeated for consecutive three years to find the effect of microbial inoculants with auxin precursor L-TRP and mean of three years was reported in the manuscript. The microbial inoculants were applied as seed coating. The bacterial inoculation showed promising results as compared to control. However, the consortium of PGPR and P-solubilizer with precursor had the significant effects on cotton yield during all three years of experiment. The consortium increased the yield parameters of cotton i.e., 1810 kg/ha in comparison with un-inoculated control i.e., 1672 kg/ha. Individual applications of PGPR and P-solubilizer also had significant effect on the yield compared to control. Hence, it was concluded that the interaction of bacterial consortium and precursor (precursor inoculum interaction) proved to be the best to improve the cotton yield.