Alternative Weed Control Methods during Grape Establishment in the United States Upper Midwest
A field experiment was conducted to determine the effects of three mulches (straw, landscape fabric, and woodchip) and a single spring herbicide application (combination of oryzalin, flumioxazin, and glyphosate) on annual weed control and grapevine establishment in North Dakota. Vine growth, bud-break timing, bud hardiness and soil conditions were monitored to determine weed control method effects on vine progress. More consistent yellow foxtail (Setaria glauca L.) control occurred in mulched plots compared to plots treated with herbicide, particularly late in the season. In 2009, vines in mulched plots’ bud-break date were up to five days later when compared to vines grown in herbicide treated plots. However, no differences were observed in the spring of 2010. Overall, differences in growth rate were due to cultivar differences and not weed control methods. Results suggest that any of the three mulches could be used for annual weed control in northern vineyards during establishment as they offered at least as much weed control as the herbicide control and did not adversely affect vine establishment. However, continued research is needed to determine if mulches will alter fruit yield and quality upon vine maturation and together influence winter dieback of vines.