INTEGRATED WEED MANAGEMENT IN COMMON BEAN (Phaseolus vulgaris L.) AT WOLAITA SODO, SOUTHERN ETHIOPIA

Abstract

Common bean production is severely infested by weeds in Wolaita Zone, Southern Ethiopia. Field experiment was conducted to assess the integrated effect of different weed management practices and herbicides on the growth and yield of common bean and to evaluate the economic feasibility of weed management practices in common bean in 2014 at Wolaita Sodo. The experiment comprises of fifteen treatments which included two herbicides (s-metolachlor and pendimethalin) applied as pre-emergence alone and in different combinations, hand weeding and hoeing, weedy check all with and without mulching and weed free check laid out in randomized block design with three replications. Weed community recorded included 55.6% broadleaved, 33.3% grass and 11.1% sedge. The density of broadleaved, grass and sedge was significantly influenced by weed management practices both at 2 and 12 weeks after crop emergence (WAE). At 2 WAE, application of pendimethalin 1.0 kg ha-1 + mulching resulted in significant decrease in total weed density over weedy check. At 12 WAE pendimethalin 1.0 kg ha-1 + hand weeding and hoeing 5 WAE significantly reduced broadleaved and total weed densities over the other treatments, while in case of grass weed, it was statistically in parity with s-metolachlor 0.50 kg ha-1 + pendimethalin 0.75 kg ha-1 + mulching, hand weeding and hoeing at 2 and 5 WAE and hand weeding and hoeing at 2 WAE supplemented with mulching. Weed dry weight varied significantly in response to weed management practices at 2 WAE. However, at 12 WAE this has no significant difference with pendimethalin 1.0 kg ha-1 + hand weeding and hoeing 5 WAE, s-metolachlor 0.75 kg ha-1 + pendimethalin 0.75 kg ha-1 + mulching and hand weeding and hoeing at 2 and 5 WAE. Herbicide mixtures and mulching did not alter weeds infestation to a considerable level. Application of pendimethalin 1.0 kg ha1 + hand weeding and hoeing 5 WAE performed better than other herbicidal treatments in enhancing days to flowering and physiological maturity and increased yield attributing characters of common bean. The highest grain yield (1982 kg ha-1) and net returns (ETB 17362 ha-1) was obtained with this treatment followed by two hand weeding at 2 and 5 WAE.