Abstract

Tef [Eragrostis tef (Zucc.)Trotter] is an ancient and major cereal crop in Ethiopia. Increasing tef yield partly requires developing cultivars that are tolerant to low moisture supply. An experiment was carried out using 18 tef genotypes grown during September to December, 2010, under two water supply environments (stress during grain filling period, and non-stress) to identify genotypic variations in drought tolerance indices and to investigate the relationships between grain yield and drought tolerance indices in tef. Grain yield (gm^-2) in respective stress (Ys) and non-stress (Yp) environments ranged from 55 to 100 and 108 to 203, respectively. Tolerance index(TOL), stress susceptibility index(SSI), stress tolerance index (STI), mean productivity (MP), geometric mean productivity (GMP), and yield index (YI) ranged from 45 to 118, 0.82 to 1.24, 0.29 to 0.88, 84 to 149, 80 to 138, and 0.76 to 1.39, respectively. The correlations among Yp, Ys, MP, GMP, STI, and YI were positive (r > 0.80, p<0.01). TOL was positively correlated with Yp (r= 0.91, p < 0.01), Ys(r= 0.48, p<0.05), and SSI(r= 0.72, p< 0.01). This experiment suggests the possibility of using MP, GMP, STI and YI to improve Tef yield under moderate stress and non-stress environments.

Key words: Tef, Eragrostis tef, grain yield, drought tolerance indices.