Chemical Management of Weeds in Common Bean (Phaseolus vulgaris)

Abstract

Common bean production (Phaseolus vulgaris) is severely infested by weeds inEthiopia. Field experiments were conducted in 2012 and 2013 at Ambo University, Ethiopia, to determine the effect of pre-emergence herbicide s-metalachlor on weed dynamics and yield of common bean (Phaseolus vulgaris) in completely randomized block design with three replications. The field experiments were comprised of 5 treatments including s-metolachlor (dual gold) 1.00, 1.50 and 2.00 kg ha -1 , weed free and weedy check were used. The common bean in both years were infested with Amarathus hybridus L., Datura stramorium, Erucastrum arabicum Fisch and May, Galinsoga parviflora cav., Ipomea ariocarpa, Nicandra spps, Oxalis corniculate L., Oxalis latifolia L. and Polygonum nepalense Meisn. Among the treatments, hand weeding standard check and s-metolachlor at 2.00 kg ha -1 significantly reduced density and dry weight of weeds during 2012 and 2013 years. Moreover, hand weeding and s-metolachlor at 2.00 kg ha -1 significantly increased the plant height, number of pods per plant, and seeds per pod as compared to other treatments. The highest grain yield was recorded on hand weeding plot followed by s-metolachlor at the rate of 2.00 kgha -1 . However, no significant difference was observed between them, whereas, the lowest grain yield was recorded on untreated plot (weedy check). Weed infestation resulted in a caused-a-yield reduction of 72.5% and 63.5% in 2012 and 2013, respectively. Preemergence application of s -metolachlor at the rate of 2 kg ha -1 was found to be more effective in controlling weeds and increased the c yield in common bean.

Adventitious Flora and its Behavior in Common Bean (Phaseolus vulgaris L.) Cultivated under Different Weed Management Methods in the Upper Katanga, DR Congo

“…Approached in the same direction, Bertrand and Dore (2008) have demonstrated the positive impact of cultivation on the physical, chemical and biological soil properties, but the flip side was mentioned by Rasmussen (1992) which highlights its negative effect on some cereals with loss of grain yield of triticale who is intolerant. The feat achieved by manual weeding as in our case was discussed simultaneously by Amare and Mohammed (2014) who argue that pretreatment emergent of S-metolachlor 2 kg haG 1 slightly increased grain yield of beans, unlike to manual weeding.…”

“…Furthermore, De Carvalho and Christoffoleti (2008) circumscribed sensitive phonological phases of culture which spread during the appearance of the first trifoliate leaf stage and pre-floral and floral corresponding to a strong mobilization of energy by the culture for the beginning of the production. Later, Amare and Mohammed (2014) have demonstrated the action of weed nuisance on relative growth rate and net rate of assimilation, thus affecting yields. According to Adigun (2001) and Kasongo (2009) in tropical areas management of weed remains manual because agriculture is mainly peasant.…”