Weed Control Efficacy, Growth and Yield of Potato (Solanum tuberosum L.) as Affected by Alternative Weed Control Methods

Abstract

Two field experiments were conducted to assess the response of growth, yield and quality of potato crop as well as weed control efficacy (WCE) to different colours (blue, white and black) of plastic mulches, biodegradable (plastic and rice straw) mulches, infrared transmitting (IRT) plastic mulch and natural herbicides (acetic acid 20% (AA), citric acid (CA) 10% and AA 10% + CA 5%) in comparison with hoeing, metribuzin herbicide and unweeded check. At 90 days after planting, black and biodegradable plastic mulches recorded WCE significantly higher than hoeing treatment with values of 98.1% and 93.8%, respectively, compared with 83.1% for hoeing. High WCE was recorded by AA 20% (90.7%), rice straw (90.4%), white (89.6%), IRT (88.1%) and blue (83.7%) plastic mulches and AA 10% + CA 5% (80.5%) which were similar to hoeing treatment. The lowest WCE (70.2%) was obtained by CA 10% treatment. The highest plant shoot fresh weight was recorded in biodegradable and black plastic treatments. Weed infestation in the unweeded plots reduced marketable yield of potato by 57.8%. All plastic and rice straw treatments produced total and marketable yields similar to hoeing treatment. The increase of marketable yield under synthetic and biodegradable mulches ranged from 118.6 to 155.1%. Application of AA 20% and the mixture of AA 10% + CA 5% achieved tuber yields similar to metribuzin herbicide. Biodegradable plastic recorded the largest tuber volume and the lowest physiological disorder yield. The highest starch content was recorded in black plastic and rice straw mulch treatments. It was concluded that mulches and natural herbicides may provide alternative safe weed management methods to hoeing and/or synthetic herbicides in potato crop, especially for new reclaimed areas and organic farms.