Effect of Plant Spacing and N Rates on the Growth and Yields of Rice at Abakaliki Ebonyi State, Southeast Nigeria

To elicit information on the optimum spacing and N fertilizer rates for rice production under rain fed conditions at Abakaliki Agro-ecological zone, field trials were conducted at Ikwo with rice variety CISADANE as test crop for two years (2007 - 2008). The design of the experiment was a split plot in a randomized complete block. The treatments were N fertilizer rates (0, 80, and 160 kg N ha-1) and plant spacing (10 cm x 10 cm, 20 cm x 20 cm and 30 cm x 30 cm). The parameters measured were plant height, number of tillers and grain yield. Significantly (p<0.05) higher number of tillers and plant height were obtained when 80 kg N ha-1 was applied compared to the application of 0, and 160 kg N ha-1. Plant height and number of tillers were significantly (p<0.05) higher when the crops were transplanted at 30 cm x 30 cm spacing than transplanting at 10 cm x 10 cm and 20 cm x 20 cm. Application of 80 kg N ha-1 gave 0.72 and 0.61 t ha-1 more grain than 0 kg N ha-1. There were no significant differences in grain yield between the application of 80 kg N ha-1 and 160 kg N ha-1. Rice transplanted at 30 cm x 30 cm spacing yielded 2.36 and 1.32 t ha-1 significantly (p<0.05) higher grains than those transplanted at 10 cm x 10 cm and 20 cm x 20 cm. It was concluded that application of 80 kg N ha-1 and transplanting rice at 30 cm x 30 cm spacing is most suitable for rice production in the study area.