Performance Evaluation of Advanced Bread Wheat Genotypes for Yield Stability Using the AMMI Stability Model

Bread wheat (Triticum aestivum L.) is one of the staple foods for large proportion of the Ethiopian population. Ethiopia is the largest wheat producer in Sub-Saharan Africa, The country cultivates a total of more than 1.6 million hectares, and yet imports about 1/3 of the national requirement to make up for annual deficits. To increase wheat production in the country, adaptive breeding has been in progress to develop promising lines for broad adaptation or to develop wheat varieties that perform well over diverse agricultural environments. In this study a total of fifteen genotypes, eight advanced lines from CIMMYT/ICARDA source, five Ethiopian crosses, and two checks, were tested across six locations during 2017 and 2018 seasons. Yield stability index (YSI) was calculated by ranking the mean grain yield of genotypes (RY) across environments and by ranking the AMMI stability values (RASV). The smallest YSI value of 5 was exhibited by variety Hidass and entries ETBW8084, ETBW9037, ETBW9470 and ETBW8459 had YSI values of 6, 7, 12, and 12, respectively, and indicated stability across locations with comparatively higher yields. The highest YSI (30) was recorded by genotype ETBW8075 which is characterized as unstable and low yielder. ETBW 8084 was high yielder and with bi<1, (but bi is 1.236) it indicated that it will perform well in diverse environments including marginal and low yielding areas. On the other hand ETBW8075, with high deviation from regression, Si 2= 4.77, was the lowest yielder and poor performance across tested locations. Therefore, ETBW8084 is recommended for production in diverse agro-ecological environments, and ETBW9470 is recommended for optimum environment. These two lines will be tested national variety verification trials (NVVT) in 2018 as candidate varieties for a possible release for production by the resource poor farmers.