Evaluation of Combined Weed Control Practices on Weed Dynamics, Yield and Economic Return in Common Bean (Phaseolus vulgaris L.) at Wolaita Sodo, Southern Ethiopia

Abstract

The field experiment was conducted in Wolaita Zone, Southern Ethiopia, to evaluate different weed management practices on weed dynamics, yield and economic return in common bean in 2014. The experiment comprised 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. The application of pendimethalin 1.0 kg ha^-1+ mulching at 2 weeks after crop emergence (WAE) resulted in significant decrease in total weed density over weedy. Weed dry weight varied in response to weed significantly 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. At 12 WAE, the highest weed control efficiency (99.8%) was obtained with hand weeding and hoeing at 2 and 5 WAE which is statistically at parity with pendimethalin 1.00 kg/ha+ hand weeding and hoeing 5 WAE (99.4%. Weed infestation throughout the growing period suppressed the plant height by about 29.6 to 95.3% compared to other treatments. The highest number of pods per plant was recorded under complete weed free and it was statistically in parity with pendimethalin at 1.0 kg ha^-1+ hand weeding and hoeing 5 WAE. Weedy check resulted in significant decrease in number of pods per plant which varied between 28.6 and 54.4% over other treatments. The highest number of seeds/pod was also obtained with complete weed free plots but in addition to pendimethalin at 1.0 kg ha^-1+ hand weeding and hoeing 5 WAE, Weight of hundred seeds was maximum with complete weed free which was statistically in parity with the application of pendimethalin at 1.0 kg ha-1 + hand weeding and hoeing at 5 WAE and two hand weeding and hoeing 2 and 5 weeks after crop emergence (WAE) treatments. Highest grain yield (1982 kg ha^-1) and net returns (ETB 17362 ha^-1) was obtained with the application of pendimethalin 1.0 kg ha^-1 + hand weeding and hoeing 5 weeks after crop emergence. Generally, it could be concluded that pendimethalin 1.0 kg ha-1 combined with one hand weeding and hoeing at 5 WAE was the most appropriate method for effective weed management and profitable production of common bean.

Keywords:Herbicides combination, mulch, pendimethalin, pre-emergence, s-metolachlor, yield, economic feasibility

DOI: 10.7176/JBAH/12-6-01

Publication date:March 31^st 2022