Effect of Weed Management Methods on the Growth and Yield of Ginger in Jimma, Ethiopia

Abstract

A field experiment was carried out at Jimma Agricultural Research Center to determine the best weeding practice for ginger under Jimma condition. The experiment was carried out between 2010 and 2011 cropping seasons.Ginger was subjected to nine weeding regimes using randomized complete block design with three replications The treatments were: hand weeding at 30,60,90,120,150 & 180 days after planting, hand weeding at 45,75,105,135 &165 days after planting, hand weeding at 60,90,120,& 150 days after planting, mulching at planting followed by hand weeding at 45 and 75 days after planting,  mulching at planting followed by hand weeding at 60 and 90 days after planting, hand weeding at 30 and60 days after planting followed by mulching once followed by one hand weeding as    needed, hand weeding at 45 and 75 days after planting followed by mulching once followed by one hand weeding as needed,  weed free and weedy controls. The result showed that the major weeds recorded were: Cynodon spp., Cyprus spp., Digitaria spp./ Commelina spp., Bidens pilosa, and Ageratum conyzoides. The result also reveled that ginger rhizome yield was highly significantly (p<0.1) affected by weeding regimes in both years that as hand weeding frequency increased ginger yield also increased. The result reveled that one early hand weeding applied between 30 and 45 days after planting was critical for high yield of ginger. When the first hand weeding was delayed up to 60 days from planting yield of ginger was reduced tremendously. However, the result showed that by mulching ginger at planting the first hand weeding can be delayed up to 60 days without yield being affected. Mulching ginger at planting followed by two hand weeding at 60 and 90 days gave similar yield compared with the weed free treatment where plots were kept free of any weed growth and the most frequently weeded treatment with six hand weeding frequencies.  Similarly, hand weeding at 30 and 60 days followed by mulching once also gave comparable yield with the weed free treatment. In addition, the result also revealed that mulching at planting enhanced the fast germination and emergence of ginger compared with none mulched ginger.  On the other hand, the result also showed that ginger was poor competitor of weed competition that ginger growth was affected as hand weeding was delayed beyond 30 days after planting. The highest weed biomass was recorded from the control treatment and   when weeding was totally ignored yield reduction as a result of uncontrolled weed growth amounted 100 % under Jimma condition