Variation And Interrelationships Among Yield And Yield Components in Lowland Rice Genotypes (oryza sativa l.) In Mwanza Region

ABSTRACT 

Three experiments were conducted at Ukiriguru, Misungwi District, Nansole and Bukindo in Ukerewe district with the aim of investigating genotypic and phenotypic variation, interrelationship and magnitude of Genotype x Environment interactions and stability parameters for rice grain yield and yield components and other agronomic characters in lowland rice genotypes. The experiments, using Randomized Complete Block Design were conducted during 2012 main rain season. Fifteen genotypes obtained from Sokoine University of Agriculture and a local check was used for the experiments. Analysis of variance revealed that there were significant differences among genotypes for all variables studied at all sites. There were no significant differences among locations studied while significant G x E interaction was observed for all the traits except for panicle weight and 1000 grain weight. Furthermore, there was predominance of positive and significant correlation between grain yield and various yield components. In addition, broader genotypic and phenotypic coefficient of variation coupled with higher heritability was observed which emphasizes presence of genetic variability for studied characters. Importantly, grain yield per plant and number of panicles per plant had strong relationship with grain yield reflecting the great contribution of these traits toward grain yield. Thus using these traits as selection criteria would remarkably result into increase in rice grain yield. The presence of significant Genotype x Environment interaction for all characters except for panicle weight and 1000 grain, suggested the need for testing the genotypes in multilocations in order to develop or select genotypes with wide adaptability or recommend varieties for specific environment.