Breeding Sorghum for Striga and Drought Tolerance: Genotype x Environment Interaction and Yield Stability of Striga Resistant Sorghum [Sorghum bicolor (L.) Moench] Hybrids

Sorghum production constraints vary from region to region within Ethiopia. However, drought and striga are reported to be important sorghum production constraints in the north and northeastern parts of the country. Stiriga hermonthica, the dominant striga species, is the most severe in the highly degraded north, northwestern and eastern parts of the country, viz. Tigray, Wollo, Gonder, Gojam, North Shewa and Hararghe. Over 80% of sorghum in Ethiopia is produced under severe to moderate drought stress conditions. In spite of biotic and abiotic stress tolerance, it is largely affected by genotype × environment interaction (GEI), making it difficult and expensive to select and recommend new sorghum genotypes for different environments. Hybrids have been found better suited than varieties to such stress environments as a result of earliness, better adaptation and stability.