The low average grain yield (0.7 ton ha−1) of tef in Ethiopia is mainly attributed to low soil fertility, and inappropriate tillage and weeds control practices. Despite this, limited scientific information has been documented so far on their interaction effects on tef crop productivity in northern Ethiopia. The objective of this study was to assess the separate and interaction effects of tillage, fertilizer, and weed control practices on tef yield and yield components in the conditions of northern Ethiopia. A two-year study (2008-2009) was conducted using split-split-plot design with three replications. In the main plot, three tillage treatments: conventional tillage (6 times tillage passes) (T1), four times tillage passes (T2), and reduced tillage (single tillage pass at sowing) (T3) were applied. The fertilizer treatments in the subplots were: no fertilizer (F1); 23 kg N ha−1 (F2); 23 kg N ha−1 and 10 kg P ha−1 (F3); 23 kg N ha−1 and 2.5 ton manure ha−1 (F4); and 2.5 ton manure ha−1 (F5). The sub-subplot weed control treatments included farmer weed control practice or hand weeding (W1); 2,4 D at 0.75 kg ha−1 at five-leaf stage; 2,4 D at 0.75 kg ha−1 at six-leaf stage; 2,4 D at 1.5 kg ha−1 at five-leaf stage; and 2,4 D at 1.5 kg ha−1 at six-leaf stage. This study showed that the separate and interaction effects of tillage, fertilizer, and weed control practices significantly affected tef crop yield and yield components in both crop seasons. T2 increased tef yield by >42% over the other tillage and F3 increased yield by >21% over the other fertilizer treatments. Grain yield increased by >23% due to W1. This study thus suggested that promising treatments such as T2, F3, and W1 should be demonstrated at on-farm fields in order to evaluate their performance at farmers’ conditions.
Effect of Weed Control Methods and Canopy Characteristics on Weed Biomass, Yield and Yield Components of Two Contrasting Cassava Varieties in the Rainforest Zone of Nigeria
