The Effect of Tillage Frequency and Weed Control on Yield of Tef (Eragrostis tef) in Yielmana-Densa Area, Northwestern Ethiopia

Tef is the major crop and has the highest share of grain production in Ethiopia. However, its productivity is limited to 896 kg/ha. An experiment was conducted on nitosols in the Yielmana-Densa area of northwestern Ethiopia in the main cropping seasons of 2002-2004. The objective of the experiment was to determine the optimum tillage frequency, time and weeding frequency for tef production in the Yielmana Densa area. The experiment was designed in a factorial split plot using tillage as a main plot and weeding as sub plot. The tillage consisted of four frequencies (seven plows, five plows, three plows and one plow + roundup) and the weeding consisted of four levels (no weeding, weeding once at tillering, weeding once at stem elongation and weeding twice at tillering and stem elongation stages of the crop). Grain yield increased linearly as tillage frequency increased. Twice weeding increased yield by 39% over un-weeded. The highest grain yield was obtained when seven times plow was combined with weeding twice which resulted in an increase of yield by 96% over the lowest yield treatment (one plow + roundup + un-weeded). However, three times plowing combined with hand weeding at tillering was found to be an economical practice with the highest marginal rate of return and net benefit. It is, therefore, recommended to small-scale farmers around Yielmana Densa as a way of promoting sustainable crop production with fewer unfavorable effects on the environment. Keywords: Nitosols; Tef; Tillage; WeedEast African Journal of Sciences Vol. 2 (1) 2008: pp. 35-4