The performance of true seed shallot lines under different environments of Ethiopia
Adama Science and Technology University, School of Agriculture, Nazret, Ethiopia (1)
Seven true seed shallot lines were evaluated for 3 years at 3 locations to determine their performance and stability. Stability differences were assessed on the basis of linear regression of the lines on environmental index and on deviation from linear function along with the mean yield. The combined analysis showed that bulb yield over 9 environments ranged from 15.1 to17.5 t ha-1 with overall mean yield of 16.5 t ha-1, and lines Vethalam, Tropix, Dz-94 and Athlas gave the highest mean yield. The combined analysis of variance showed significant (p<0.05) genotype and genotypebyenvironment effects on bulb yield. The regression coefficient for bulb yield ranged from 0.72 to 1.36. The regression coefficient of two high yielding lines (Vethalam and Athlas) was above 1, and was higher in environments where growing conditions were favorable. High and significant deviations were obtained for lines Tropix and Athlas and these lines werefoundunstable to change in environment. However, line Tropix showed specific adaptation to low yielding environments of Kulumsaand Melkassa.The best line Vethalam with a small deviation from regression was found widely adaptable to different environments and it was released with local name ‛Yeras’ to be grown in Rift Valley and similar areas in Ethiopia.