Effect of seeding rate and number of seedlings/hill on the growth and yield of hybrid rice (Oryza sativa) grown in dry (Boro) season

A field experiment was conducted in split-split plot design with three replications during the dry (boro) season of 2000–01 and 2001–02 on silty-clay soil at Rice Research Station, Chinsurah, West Bengal to test the performance of rice hybrids and to find out the optimum seeding rate for sowing in the nursery and optimum number of seedlings/hill for transplanting in the main field in order to obtain the higher productivity of hybrid rice (Oryza sativa L.). Two rice hybrids, namely, Pro Agro 6201 (PA-6201) and DRRH-1 and one inbred high yielding variety (HYV), Kshitish were assigned at random to the main plots. Three different seeding rates viz., 10, 20 and 30 g/m² in the nursery were assigned to the sub-plots and two levels of number of seedlings/hill viz., 1. seedling and 2. seedlings/hill were allocated randomly to the sub-sub plots. Both the rice hybrids exhibited significantly higher number of tillers/m² and plant height than the inbred HYV, Kshitish. Elaboration of yield-attributing characters was significantly more in case of hybrid varieties as compared to the inbred HYV, Kshitish. Both the rice hybrids produced significantly higher grain yield, being 25.9–33.33% higher than the inbred HYV, Kshitish. Lower seeding rates of 10 and 20 g/m² resulted in significant development in number of tillers/m² and all yield attributing parameters except the 1000-grain weight and ultimately brought about 12–33% increase in grain yield of hybrid rice over the seeding rate of 30 g/m². Different growth and yield attributes, grain and straw yield of hybrid rice did not differ significantly due to transplanting of one seedling and two seedlings/hill.