The 2009 ASHS Annual Conference
Cultural and Chemical Weed Control In Newly Established French-American Hybrid Grapes
Weed control evaluations 5 weeks after treatment (WAT) indicated that all treatments provided satisfactory control (≥ 85%) of common lambsquarters, horseweed, and yellow foxtail. Glyphosate applied just prior to the application of wood chips or wheat straw did not provide the anticipated control of Canada thistle or dandelion. Populations were variable, but more prevalent in these treatments. Spot applications with glyphosate reduced the Canada thistle population and eliminated the dandelions. Weed control evaluations were similar at 16 WAT except that the yellow foxtail control decreased in the chemical treatment. Soil water content was greater within the wheat straw mulch treatment than other treatments and soil temperature was cooler until September when the soil temperature within the chemical treatment began to reflect the much cooler night temperatures. Soil water content was lowest and soil temperature had the greatest daily fluctuation within the chemical treatment. Soil temperature and soil water content differences did not affect vine growth (stem number and stem height) but may affect winter hardiness, bud break, fruit production, or fruit ripening. These factors will be evaluated the next two years as well as weed control to determine if cultural weed management methods are feasible strategies for grape production in North Dakota.