Seed Priming Influence on High Temperature Tolerance and Weed Suppressive Ability of Late Sown Dry Direct Seeded Winter Rice

Seed priming is a pre-sowing hydration technique which leads to a physiological condition triggering germination and enhancing uniform seedling emergence. It is a promising tool for enhancing drought tolerance in plants which is essential for promoting economic development by coping up with the adverse effects of climate change on crop productivity. So, a better understanding of seed priming efficacy is required. Therefore an experiment was conducted with a view to investigating the effect of seed priming agent on the weed growth and yield performance of high yielding rice variety BRRI dhan29 sown on different dates following dry direct seeded condition in boro season. Two sowing dates viz., 20th January (early or optimum sowing as control) and 20th February (late sowing as high temperature stress during reproductive stage) and seed priming agents included NaCl (20000 and 30000 ppm), KCl (20000 and 30000 ppm), CaCl2 (20000 and 30000 ppm), CuSO4 (50 and 75 ppm), ZnSO4 (10000 and 15000 ppm), Na2MoO4 (2 and 3 ppm) and PEG (100 and 150 ppm) were used. Plant height and tillers of BRRI dhan29 were significantly enhanced when seeds were sown early (20th January) and due to seed priming at early stage and at harvest. Among the yield parameters grains panicle-1, grain yield, and straw yield were produced more by early sowing (20th January). Grains panicle-1, 1000-grain weight, and grain yield were positively influenced due to seed priming. Considering the growth and yield parameters and yield of rice, early sowing and seed priming with KCl or CaCl2 were found as the best. Seed priming produced no significant effect on the weed growth. There was no significant effect of interaction between sowing date and priming agent on crop characters and yield parameters. Therefore, seed priming with 20000 ppm KCl or 20000 ppm CaCl2 and early sowing is recommended for increasing the yield of dry direct seeded boro rice (BRRI dhan29). If somehow early sowing is not possible, seed priming with 20000 ppm KCl or 20000 ppm CaCl2 is highly recommended or mitigating temperature stress during reproductive stage and enhancing yield of BRRI dhan29 under dry direct seeded, late sowncondition.