GENOTYPE X LOCATION X PLANTING PATTERN INTERACTION AND STABILITY ANALYSIS OF SORGHUM [Sorghum bicolor (L.) Moench] VARIETIES IN DRYLANDS OF ETHIOPIA

Abstract

Sorghum is one of the major staple food crops grown in the poorest and most food insecure regions of Ethiopia. It is typically produced under adverse conditions, such as low input use and marginal lands. Its production is mainly constrained by the prevalence of drought; that is, the soil water deficit during grain filling stage of sorghum is considered among the major causes of grain yield loss for sorghum production in the dryland of Ethiopia. Factorial combination of treatments (five sorghum varieties and three planting patterns) were tested in 2018 cropping season at two locations in dryland of Ethiopia, namely Sheraro and Babile, using randomized complete block design with three replications. The planting patterns include conventional planting, single- and double-skip row systems. Thus, the present study was aimed to examine the effect of genotype by location by planting pattern interaction on grain yield and yield related traits in sorghum and to identify stable and adaptable varieties in grain yield in combination with productive planting patterns. Data collected from each location were analyzed both for individual location as well as across location. The result of combined analysis of variance revealed the presence of significant differences among genotypes, location, planting pattern, genotype by location interaction and location by planting pattern for most of the studied traits. Additionally the result displayed the presence of significance differences among genotype by planting pattern interaction and genotype by location by planting pattern interaction for some of studied traits. Among tested varieties Teshale (2141.1 kg/ha) and ESH-1(2077.2 kg/ha) was the top yielder while Dekeba (1538 kg/ha) was the lowest yielder. Considering most of the stability parameters, such as Wricke ecovalence, cultivar superiority, AMMI stability value (ASV), yield stability index, GGE biplot and mean yield Teshale variety were identified as the most stable with the mean yield above the grand mean. GGE biplot identified Babile with conventional planting as the more discriminating, most representative and ideal testing environment; which was able to provide unbiased information about the performance of the tested varieties. In conclusion, the variety identified as stable and desirable for cultivation across location could be recommended for wider adaptation. Among planting pattern conventional planting was recommended for the study area. However, the study was conducted only at two locations in single cropping season with only five varieties. So the information generated from this study gave an insight for further study using diverse locations, seasons and more number of varieties to confirm the results of current study and to generate more reliable information on the effect of genotype, location, planting pattern and their interaction on performance and stability of sorghum.