THE PERFORMANCE OF TRUE SEED SHALLOT LINES UNDERDIFFERENT ENVIRONMENTS OF ETHIOPIA

Seven true seed shallot lines were evaluated for 3 years at 3locations to determine their performance and stability. Stability differences wereassessed on the basis of linear regression of the lines on environmental index andon deviation from linear function along with the mean yield. The combinedanalysis showed that bulb yield over 9 environments ranged from 15.1 to17.5 t ha^-1with overall mean yield of 16.5 t ha^-1, and lines Vethalam, Tropix, Dz-94 andAthlas gave the highest mean yield. The combined analysis of variance showedsignificant (p 0.05) genotype and genotype by environment effects on bulb yield.The regression coefficient for bulb yield ranged from 0.72 to 1.36. The regressioncoefficient of two high yielding lines (Vethalam and Athlas) was above 1, and washigher in environments where growing conditions were favorable. High andsignificant deviations were obtained for lines Tropix and Athlas and these lineswere found unstable to change in environment. However, line Tropix showedspecific adaptation to low yielding environments of Kulumsa and Melkassa. Thebest line Vethalam with a small deviation from regression was found widelyadaptable to different environments and it was released with local name ‛Yeras’ tobe grown in Rift Valley and similar areas in Ethiopia.