Genotype x Environment Analysis of Upland Medium Duration, Nationally Coordinated Rice Evaluation Trials (CRET) for Varietal Recommendation
A. T. Maji
National Cereals Research Institute Badeggi, Niger State, Nigeria.
A. S. Gana *
Department of Crop Production, Federal University of Technology, Minna, Niger State.
E. O. Bright
National Cereals Research Institute Badeggi, Niger State, Nigeria.
M. N. Ukwungwu
National Cereals Research Institute Badeggi, Niger State, Nigeria.
A. A. Ochigbo
National Cereals Research Institute Badeggi, Niger State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Multi-locational rice evaluation trials were conducted in six locations across Nigeria to select promising varieties that could be cultivated by farmers. Entries were planted in a randomized complete block design replicated three times in each location. Grain yield records of the entries were taken in all the locations. Data were analysed using combined analysis of variance, regression, Additive Main Effects and Multiplicative Interaction (AMMI) and pattern analysis. G x E analysis of transformed data showed that there was no significant differences in grain yield among varieties and at the locations (p=0.05). There was however a high interaction of G x E (location) and location x year (p=0.05). Joint regression analysis which gives a measure of stability showed that WAB 96-1-1, IDSA86, M2 and IR47701-6-3-1 were the most stable varieties across the locations. Using AMMI analysis two varieties, IR47701-6-3-1 and IRAT 317 are the best varieties having high linear response to environments and could also produce high grain yield in poor environments. The pattern analyses group the varieties into three groups. This provides regional stability of the varieties and therefore specific site selection of the cultivars.
Keywords: Genotype, environment, stability, grain yield.