Genotype by environment interaction and yield stability of hybrid maize varieties evaluated in three locations of mid altitudes of Rwanda

A multi-environment yield trial is important to understand the genotype by environment interaction and to select high performing and stable crop varieties. The aim of this study was to identify high yielding and stable hybrid maize varieties for mid altitudes of Rwanda, to compare the performance of new hybrid varieties with commercial checks, and to determine the extent of genotype by environment interaction. Maize is a staple crop used to fight hunger and malnutrition in developing countries. Different varieties have been released to increase yield including Open Pollinated Varieties (OPVs) and hybrids. Genotype by Environment interaction is an issue that all breeding program need to overcome. In the future, improved varieties will be needed in order to increase income for farmers and help in food security Field experiments were conducted to assess the performance and the stability of 27 maize varieties in the mid altitudes zone of Rwanda in the Cyabayaga, Rubona and Bugarama sites. The experimental design was alpha lattice (0,1) with a Randomized Complete Block Design (RCBD). Data were collected for a number of characters i.e. silking, Antesis-Silking Interval (ASI), plant height, plant aspect, ear per plant, husk cover, ear aspect, ear rot and grain yield. Data were analyzed by GenS Stat statistical computer package, Discovery Edition. ANOVA and AMMI analysis were applied to assess the performance and the stability of varieties and the degree of genotype by environment interaction (G×E). In addition, Principal Component Analysis (PCA) and cluster analysis were conducted to assess relationships between varieties. The results showed that RHM1706, RHMM1701, RHM1409, RHMM1707, WH509, RHMM1704, RHM407, WH101, RHMM1710, RHMM1708, PAN53 and RHM104 were stable across locations. Furthermore, the evaluated varieties were found to cluster into five groups. Varieties found to be most stable are recommended for further use.