Effect of Seed Rate and Row Spacing on Yield and Yield Component of Rain fed Lowland Rice Variety (Ediget) at Assosa, Western Ethiopia

Two different sets of field experiments were conducted at Woreta, Metema, Pawe, Addis Zemen and Assosa in Ethiopia during 2008/09 to 2011/12 main cropping seasons with the objective of identifying high yielding, stable, early maturing and disease resistance rice varieties for upland and lowland production systems. In experiment-I, 13 upland rice genotypes (NERICA and some non-NERICA) including one check were evaluated at Woreta, Metema and Pawe. In experiment-II, 20 lowland rice genotypes including one check were evaluated at Woreta, Addis Zemen, Pawe and Assosa. In both sets of experiments, the trials were laid out in a randomized complete block design of three replications. The combined analysis of variance in experiment-I revealed significant genotypic, environmental and genotype x environment interaction effect for grain yield. The highest yielding genotype in Experiment-I was G2, followed by G3 with mean grain yield of 3840.3 and 3656.8 kg ha-1 , respectively. Genotype, G2 was also the most stable and diseases resistance. Similarly, in experimental-II, the highest mean grain of 4583.8 kg ha-1, 4243.2 kg ha-1, and 3825 kg ha-1 were recorded by G4, G17 and G9, respectively. Of the three genotypes, G9 with grain yield of 3825kg ha-1 was highly preferred by farmers in terms earliness and diseases resistance. Hence, based on high mean grain yield, diseases resistance and better stability, G 2 (NERICA-12) as NERICA-12 and G9 (IRGA370-38-1-1F-B1-1) as 'Hibbire', both in 2013, were recommended and released following national variety release committee evaluation and farmers fed back. Therefore, these varieties should be promoted and popularized in large scale to make use of their merits.