Department of Plant Sciences

To assess Mn efficiency of wheat (cv PBW 343) and raya (cv RLM 619), four field experiments were conducted in Mn deficient loamy sand soils. The experimental soils had pH range from 7.8 to 8.2 and DTPA-extractable Mn from 2.68 to 3.24 mg kg-1 soil. Wheat produced 57 per cent of its maximum dry matter yield (DMY) with 47 per cent of its maximum root length (RL), while raya produced 94 per cent of its maximum DMY with 80 percent of its maximum RL at 60 days of growth under Mn deficiency conditions. Spray application of 0.5% Mn solution significantly increased wheat DMY, but there was no significant effect on raya DMY. At maturity wheat produced 63 to 75 per cent of its maximum grain yield in no Mn treatment in all the four experiments. However, raya produced 96 to 98 per cent of its maximum grain yield in all the experiments in Mn deficient soils. Considering relative DMY and grain yield as a criteria of Mn efficiency, raya was more Mn efficient than wheat under Mn deficiency conditions. The results showed that raya could take up 1.2 to 1.9 times more Mn than wheat in all the experiments. Higher Mn uptake by raya than wheat even under Mn deficiency conditions could be due to its 1.9 times more root surface area that could exploit Mn from a greater volume of soil.