Assessment of Integrated Weed Management Practices on Weed Dynamics, Yield Components and Yield of Faba bean (Vicia faba L.) in Eastern Ethiopia

The experiment was conducted to assess the integrated effects of pre-emergence herbicides and hand-weeding on weed control, yield components, yield, and their economic feasibility for cost effective weed control in faba bean. The experiment consisted of 12 treatments viz. pre-emergence s-metolachlor (1.0, 1.5 and 2.0 kg ha-1) and pendimethalin (1.0, 1.25 and 1.5 kg ha-1), each at three rates metolachlor, s-metolachlor + one-hand-weeding, pendimethalin + one-hand-weeding, two-hand-weeding, complete weed free and weedy checks arranged. The weed flora consisted of broadleaved and sedge with the relative densities of 81.02 and 18.98 % at Haramaya district, and 80.83% and 19.17%, at Gurawa district, respectively. Application of s-metolachlor and pendimethalin 1.0 kg ha-1 each supplemented with hand weeding 5 WAE significantly (p ≤0.01) affected the broadleaved weeds, sedges and weed dry weight at both sites. S-metolachlor 1.0 kg ha-1 supplemented with hand weeding 5 WAE gave the lowest total number of weeds (8.29 m-2) following the weed free check. Higher grain yield (3555.8 kg ha-1) was produced with s-metolachlor 1.0 kg ha-1 supplemented with one-hand-weeding 5 WAE following complete weed-free at Gurawa. The benefit gained from s-metolachlor and pendimethalin at 1.0 kg ha-1 each supplemented with one hand weeding 5 WAE were greater than the value recorded from the weedy check by 216% and 198 %, respectively. S-metolachlor 1.0 kg ha-1 supplemented with hand weeding 5 WAE treatment resulted in the highest grain yield and economic benefit. However, in case labour is constraint and s-metolachlor herbicide is timely available, pre emergence application of s-metolachlor at 2.0 kg ha-1 should be the alternative to preclude the yield loss and to ensure maximum benefit.