Response of haricot bean (Phaseolus vulgaris L.) to row spacing and weeding frequencies in Wolaita Zone, Southern Ethiopia

Abstract

The common bean is the most important legume in Ethiopia for export and as a source of protein. Weed infestation and lack of appropriate row spacing are major factors affecting its growth and yield. However, limited research exists to determine proper weed management and optimum row spacing for improving the yield performance of haricot beans. Therefore, a field experiment was conducted in the Wolaita Zone, southern Ethiopia, to evaluate the influences of variable row spacing and hand-weeding frequencies on the growth and yield of common bean. Treatments consisting of three-row spacing and five weeding frequencies were laid out in a randomized complete block design in a factorial arrangement with three replications. Data on phenology, growth, yield components, seed yield, and weed parameters were collected and analyzed procedurally. The result showed that weeding frequencies had a significant (p < 0.05) effect on days to flowering, days to physiological maturity, plant height, leaf area, leaf area index, pod number, seed number, hundred seed weight, total above-ground biomass, grain yield, weed population, weed dry weight, weed control efficiency, and yield loss, while row spacing had a significant effect on leaf area, leaf area index, pod and seed number, grain yield, total aboveground biomass yield, and yield loss. On the other hand, the interaction effect was shown to be significantly different in the weed population only. Three times of hand weeding and the recommended row spacing of 40 cm resulted in the highest grain yields of 2549.6 kg ha-1, 2056 kg ha-1, respectively. The highest net benefit (15415.56 ETB ha-1) was recorded from hand weeding done three times, and the highest marginal rate of return (209.99) was obtained from hand weeding done two times. As a result, for greater economic benefit from haricot bean production in the studied area, twice-hand weeding after two and four weeks of crop emergence with a row spacing of 40cm could be recommended.