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Tef (Eragrostis tef (Zucc.) Trotter) is an annual small grain, panicle bearing, C4 cereal crop native to Ethiopia, where it is a major staple food. The objectives of the present study were to characterize the responses of two tef genotypes to escalating phosphorus (P) and potassium (K) levels and to determine an optimum range for P and K at which tef performance is maximized. Two experiments were carried out in the Gilat Research Station, each testing two different genotypes of tef (405B and 406W), one experiment in pots in controlled conditions, and the other in the field. In both experiments, the highest grain yield increased until 6 mg L−1 P, and declined at 12 mg L−1 P. The decline was precipitous and significant in the pot experiment, and gradual and statistically insignificant in the field experiment. In the pots experiment, the grain yield increased until 40 mg L−1 K, with no significant decrease thereafter. The effect of K concentration was only seen in the grain yield and not in the size of the other plant organs. In the field experiment, grain yield was highest at 80 mg L−1 K, but it was not statistically different from 40 mg L−1. The effect of K on growth was only apparent at maturity and not at flowering.

Developing new crops adapted to arid conditions is a promising approach to meet the increasing demand for food production under expanding aridity. Tef [Eragrostis tef (Zucc.) Trotter] is a C4 cereal crop cultivated mainly in Ethiopia and the Horn of Africa, and known for its high resilience to stressful environments. Due to their tiny size, tef seeds are traditionally sown by broadcasting and lightly covering with soil. Under semiarid Mediterranean conditions, a deeper sowing may guarantee seedling establishment while saving on irrigation water. The objective of this study was, therefore, to determine the effects of sowing depth on tef emergence, development, lodging, and productivity. Tef seeds were sown at different depths in test tubes and pots, and in two field experiments. In tubes and pots, time from sowing to emergence increased about twofold and emergence rate decreased in the deepest sowing (3 cm) treatment compared to controls (0 cm). In the pot and field trials, deep sowing (3 cm) significantly reduced plant height, shoot and root biomass, and lodging. Sowing depths of 1–2 cm allowed successful plant establishment while not exacting penalties on plant emergence or development; hence this range appears to be optimal for sowing irrigated tef.

Eragrostis tef (Zucc.) Trotter (tef) is a small annual grain, panicle-bearing, C4 cereal crop native to Ethiopia, where it is a major staple food. The objectives of the present study were to characterize the responses of two tef genotypes to escalating nitrogen (N) levels in terms of shoot, root, and grain biomass production, N concentration and uptake, and to determine an optimum N range at which tef performance is maximized. The N was applied in the irrigation water (Fertigation) in order to provide a consistent concentration of N in the root zone. A second goal was to test the feasibility of growing tef in the hot, arid conditions of the Northern Negev Desert. Two experiments were carried out in the Gilat Research Station (Negev region, Israel), each testing two different genotypes of tef (405B and 406W), and each including five replicates for each treatment. In the winter of 2015–2016, tef plants were grown in perlite filled pots in a walk-in plastic-covered tunnel. Five different N treatments were applied through fertigation, meaning the fertilizer was applied with the irrigation water (10, 20, 40, 80, 120 mg L−1). All other nutrients were applied at the same sufficient rate. In the summer of 2016, tef plots were sown in open-field and applied with four different rates of N fertilization (0, 30, 60, 120 mg L−1). Biomass of the different plant parts, SPAD values, N, P and K concentration, and the lodging index were recorded in each experiment. The harvest index was also calculated. Optimum N fertigation concentration in both experiments was between 40 and 80 mg L−1, under which the time to flowering was decreased, and yield and grain protein concentration were optimized. Underfertilization caused a decrease in overall plant growth, whereas overfertilization caused an increase in vegetative growth at the expense of grain yield. Potassium uptake increased along with increased N availability, whereas P uptake did not. The fertilization rate will always need to take into account local soil and climate conditions. The field experiment also pointed to low harvest index as a major limitation on tef cultivation in the Northern Negev.

Tef (Eragrostis tef (Zucc.) Trotter) is a panicle-bearing cereal crop plant, originating from and grown mainly in Ethiopia. Tef yields highly nutritious gluten-free grain as well as high-quality forage, therefore, interest is rising regarding tef cultivation for grain and forage outside Ethiopia. Lodging is a major factor limiting tef quality and yield, with losses estimated at 30%–35% and presumably higher under mechanical harvest. Studies in other cereal crops suggested that lowering plant density would lead to sturdier plants less prone to lodging. In this work, we reported on the effects of sowing rate on lodging, lodging-related traits, and productivity of tef under irrigated conditions. Four tef genotypes were grown under irrigation across two years at three sowing rates: low (3 kg/ha), medium (6 kg/ha), and high (common, 9 kg/ha). Grain yield and biomass did not differ significantly among sowing rates. The visually assessed lodging index (LI) increased as the season progressed, with the lowest values recorded under low sowing density. A significant difference in LI values among the tested genotypes suggested potential for crop improvement. Aerial RGB images of the field taken by an unmanned aerial vehicle twice during the second season produced a high-resolution crop surface model, which was used to assess lodging. Aerial-based LI values were significantly correlated with the ground-based ones and exhibited better capacity to identify minor differences in lodging. Among the morphological traits assessed, crown diameter, crown root number, and crown root diameter were significantly affected by sowing rate and genotype and were correlated with LI values. In summary, this study demonstrated for the first time the feasibility of tef production under irrigated Mediterranean conditions and the potential of a reduced sowing rate as a remedy for lodging.