The Effects of Genotype Earliness and Harvest Timing on Yield and Quality of Multi-Harvest Tef Under Mediterranean Conditions

Tef [Eragrostis tef (Zucc.) Trotter] is a multi-harvest annual cereal crop with outstanding fodder quality. Our overall goal was to evaluate tef as a multi-harvest summer fodder crop for Israeli dairy cows, and the objective of the study was to evaluate the effects of genotype earliness and harvest regimes on tef forage yield and quality. We report on the effects of genotype earliness and harvest timing on tef forage yield and quality for twelve genotypes (six early and six late) during two experimental years, each at different locations (hereafter environment 1-Revadim and 2-Shiller) in Central Israel. Under environment 1, forage yield was significantly greater at the grain-filling stage than at the heading stage (2100 vs. 1700 g DM/m², significant). However, cell wall carbohydrates and crude protein content were higher at heading than at the grain-filling stage (14% vs. 11%). Early-heading genotypes yielded more than late-heading at the grain-filling stage (2300 vs. 1800 g DM/m², significant). In contrast, under environment 2, late-heading genotypes yielded more than early-heading ones (2400 vs. 1400 g DM/m², significant). The in vitro dry matter digestibility (IVDMD) and in vitro neutral detergent fiber digestibility (IVNDFD) were higher at heading than at the grain-filling stage (75 vs. 53%, significant and 71 vs. 47%, significant, respectively). Late-heading genotypes had more IVDMD and IVNDFD than early-heading genotypes (54 vs. 52% and 48 vs. 46%, respectively). Under Mediterranean conditions, harvesting at heading maximizes crude protein, IVDMD, and IVNDFD, whereas harvesting at the grain-filling stage maximizes yield. All genotypes maintained high quality with low lignin, which is desirable for livestock forage. Our findings imply that tef is a high-quality multi-harvest summer crop, which could be a potential alternative fodder crop for Israeli dairy cows.