Determination of Optimum Seed Rate for Productivity of Rice (Oryza Sativa L.), at Woito, Southern Ethiopia

A field experiment was undertaken at Woito, to determine the effect of seed rate on productivity of rice (Oryza Sativa L.), at Woito. The experiment was conducted with five levels of seed rate (40, 60, 80, 100 and 120 kg ha-1). The treatments were laid out in a randomized complete block design (RCBD) with four replications. Phenological and growth parameters such as yield and yield components, total biomass and harvest index were studied. The result showed that all the phenological and growth parameters except panicle length per plant were significantly affected by the treatments. As the seed rate increased there was a proportional increment on the number of tillers per plant. Grain yield and total biomass were significantly affected by seed rate while 1000 seeds weight and harvest index were not influenced significantly by seed rate. The grain yield obtained from the seed rate of 40 kg ha-1 (5.0222 t ha-1) was higher by 66.81% compared to the seed rate of 80 kg ha-1 (1.6667 t ha-1). The noted total biomass yield advantage from the seed rate of 40 kg ha-1 (7.2875 t ha-1) was higher by 44.25% compared to the seed rate of 120 kg ha-1(4.0625 t ha-1). Therefore, it can be concluded from this result that the seed rate of 40 kg ha-1 is advisable and could be appropriate for rice production in the test area even though further testing is required to put the recommendation on a strong basis.