Abstract

Optimum plant spacing and the number of seedlings per hill are important agronomic practices for the productivity of rice. Hence, a field experiment was carried out to assess the effect of plant spacing and the number of seedlings per hill on the yield components and yield of transplanted rice under irrigation at Werer, Middle Awash. Factorial combinations of two inter-row spacings (20 cm and 30 cm), three intra-row spacings (10 cm, 15 cm, and 20 cm), and three seedlings (2, 3, and 4) per hill were laid out in a randomized complete block design with three replications. Among the main effects of the number of seedlings per hill, three seedlings per hill gave significantly (P<0.01) the highest straw yield (7169 kg ha-1) whereas the highest number of effective tillers per hill (14.49) was recorded from two seedlings per hill. Similarly, the main effects of inter-row and intra-row spacing were significant (P<0.01) on all recorded parameters except days to physiological maturity and harvest index. The highest number of effective tillers per hill (14.26 and 16.07), straw yield (6517 kg ha-1 and 7009 kg ha-1), and 1000 kernel weights (22.69 g and 22.84 g) were produced when the crop was transplanted at 30 cm inter-row and 20 cm intra-row spacing, respectively. From the interaction of number of seedlings and intra-row spacing, significantly (P<0.01) highest panicle length (22.36 cm), number of total tillers per hill (18.95), number of grains per panicle (131.6), aboveground dry biomass yield (13634 kg ha-1) and grain yield (5079 kg ha-1) were obtained from the combination of 3 seedlings per hill and 20 cm intra-row spacing. Similarly, the combination of 20 cm × 20 cm inter- and intra-row spacing gave significantly the highest number of grains per panicle (131.4), aboveground dry biomass yield (11584 kg ha-1), grain yield (4288 kg ha-1), and straw yield (7296 kg ha-1). Grain yield was significantly (P < 0.05) affected by the interaction of the number of seedlings per hill and inter-row spacing, where the highest grain yield (4314 kg ha-1) was recorded with the interaction of 3 seedlings per hill and 30 cm inter-row spacing. Therefore, it can be concluded that transplanting 3 seedlings per hill with 30 cm inter-row spacing and 20 cm intra-row spacing is tentatively recommended to obtain the maximum grain yield of transplanted rice under irrigation