Quantitative responses of tef ['Eragrostis tef' (Zucc.) Trotter] and weeping love grass ['Eragrostis curvula' (Schrad.) Nees] varieties to acid soil

Abstract

Tef [Eragrostis tef (Zucc.) Trotter] is the most widely produced and consumed cereal crop in Ethiopia. It is a gluten-free crop with growing popularity worldwide. Unlike most globally important cereals, tef has not yet been bred for tolerance to soil acidity and to aluminium toxicity. This experiment was conducted to assess the quantitative responses among some grain and pasture varieties of tef. Strongly acidic soil (pH 3.94 and acid saturation of 78%) was used to evaluate the tef varieties. A highly Al-tolerant weeping love grass [Eragrostis curvula (Schrad.) Nees] variety, Ermelo, was used as a check. A randomized complete block design (RCBD) with 4 replications was used to evaluate the materials under limed and unlimed conditions. Measurements were taken on different root and shoot parameters. The result indicated the presence of genetic variability among the tef varieties for root length, shoot length, root dry weight and shoot dry weight. All the tef varieties were inferior to the variety Ermelo of E. curvula in their Al tolerance. The brown seeded tef varieties consistently showed better Al-tolerance than the white seeded ones. A similar pattern was also observed for tolerance indices, which were computed as ratio of each parameter under unlimed versus limed condition. Highly significant correlations (r>0.9) were observed for all the parameters used to assess Al-tolerance in this experiment. This first systematic work demonstrated the presence of genetic variability for tolerance to soil acidity and Al-toxicity within tef varieties. This variability suggests the possibility to launch strategic breeding of the crop with specific adaptation to acid soil prone areas.