Effect of Sowing Methods and Seed Rates on Yield and Yield Components of Pathum Thani 1 Rice

Appropriate sowing methods and seed rates normally depend on varieties and ecosystem of rice production field. This experiment was conducted to study the effect of sowing methods and seed rates on yield and yield components of Pathum Thani 1 rice. Five sowing methods with 4 sowing rates were arranged as 5x4 factorial in a randomized complete block design with 3 replications. Treatments comprised of 1) broadcasting germinated seed (a1); 5, 10, 15, and 20 kg/rai, 2) drilling germinated seed (a2) with 30 cm row space; 5, 7.5, 10, and 12.5 kg/rai, 3) dropping 8-10 germinated seeds/spot (a3) at spot-row 36x30, 30x30, 24x30, and 18x30 cm, 4) transplanting 3 bared-root seedlings of 20-21 days for each spot; the spots were at 36x30, 30x30, 24x30, and 18x30 cm, and 5) transplanting 3 seedlings with soil lump on the roots, ageing 14-15 days, for each spot; the spots were at 36x30, 30x30, 24x30 and 18x30 cm. Paddy yield was harvested for 7.2-7.5 m2/plot, and yield components were sampling recorded for 50-60 panicles/plot. The results revealed that no. of panicles/m2, no. of filled grains/panicle, no. of unfilled spikelets/panicle, and paddy yield of various sowing methods and population densities were of non-significant difference. Average yields of 5 sowing methods had non-significant difference among 904.37-1,075.45 kg/rai, and average yield of 4 densities had non-significant difference among 939.42-1,027.23 kg/rai. This indicated that Pathum Thani 1 rice can be planted by any of the 5 studied methods as there is no significant difference in yielding. Therefore, high population density is unnecessary for Pathum Thani 1 rice cultivation because of its high tillering ability.