Interactive Effect of Applied GB and K in Improving Drought Tolerance Potential in Wheat.

Exogenous application of compatible solute like glycinebetaine (GB) and/or some osmotically active solute like potassium (K) may help the plants to retain water within cells and protect them from injury caused by drought; one of the most important abiotic stress. A 2 x 4 x 4 factorial experiment was conducted both in pots (wirehouse) as well as in field during 2009-10 at Nuclear Institute for Agriculture and Biology, Faisalabad, Pakistan. The experiment consisted of two varieties; Lasani-2008 (drought resistant) and Auqab-2000 (drought sensitive), four GB spray levels (0, 50, 100 and 150 mM) and four K spray levels (0, 0.5, 1.0 and 1.5%). Each level of GB and K was sprayed by imposing drought at grain filling stage (70 days after sowing in pots and 73 days after sowing in field). Combined spray of GB and K @ 100 mM and 1.5%, respectively mitigated the adverse effects of drought more than all other combinations on yield, yield contributing factors as well as plant water relations. However, maximum net income and benefit cost ratio were obtained where crop under drought was sprayed with 50 mM GB + 1% K solution.