Evaluation of genotype by environmental interaction and stability of early maturing fodder oat genotypes in highland of Bale, Oromia, Ethiopia

Selection of stable genotypes that interact less with the varying environment in which they are to be grown is required. The major objectives of the present study were to (i) assess the stability and yield performance of advanced Early maturing fodder Oat accessions evaluated in multiple environments, and (ii) identify stable high biomass yielding candidate cultivar(s) for possible release. A total of 19 fodders Oat accessions were evaluated against Dumant-2007 across four locations from 2022 to 2023 main cropping seasons. Randomized complete block designs (RCBD) with three replications were used. The AMMI analysis of variance for forage dry matter yield revealed highly significant (P<0.05) differences for days to flowering, days to maturity, plant height, leaf to steam ratio, seed yield, thousand seed weight and dry matter yield. The findings revealed that the highest forage dry matter yield was recorded for genotype 5448 (21.6 t/ha) and genotype 5447(21.5 t/ha) respectively. The higher leaf to steam ratio was recorded from both genotype 5447 and genotype 5448. Numerically the higher seed yield was obtained from 5447 (32.6 qt/ha), whereas the lowest seed yield was produced from genotype 5460 (21.2 qt/ha). The analysis of chemical compositions showed significant (p<0.05) differences for CP parameters among tested genotypes. The highest (12.290%) CP content was recorded from genotype 5448 followed by genotype 5447 (11.963%) whereas the lowest (9.41%) CP was recorded from 5449. The analysis of variance for AMMI also revealed significant variation for genotypes, environment and genotypes by environment interaction. The sum of squares for the first two IPCAs cumulatively contributed to 90.2% of the total GEI. Generally the mean performance, yield and stability of genotype 5448 and genotype 5447 were high and stable across the tested locations. Therefore, genotypes genotype 5448 and genotype 5447 were recommended to be promoted to a variety verification trial for further evaluation and possible release.