Integrated cultural and mechanical weed management for organic winter squash systems

"The Midwest region is a leader in cucurbit production in the U.S., but weed management is a major constraint to successful production, especially for organic growers. Mechanical weed control is a primary tool for managing weeds in cucurbits, but low selectivity, and excessive soil disturbance limit successful adoption. One approach to improving selectivity of mechanical cultivation tools is to select for varieties that are tolerant to those tools. Traits associated with tolerance to mechanical cultivation may also be valuable for establishment in reduced tillage systems. Field experiments were carried out in central Michigan to evaluate six varieties of Cucurbita pepo for their 1) tolerance to mechanical cultivation, and 2) ability to establish in a reduced tillage system. Laboratory and greenhouse testing was done to determine which seedling traits may be correlated to field performance. Results confirmed cultivar differences in tolerance to cultivation tools, with inconsistent results across runs of the experiments. No clear cultivar differences in tolerance to reduced tillage were detected. Cultivars varied in traits that may contribute to tolerance to both reduced tillage and cultivation including emergence timing, early vigor, root:shoot partitioning and anchorage force. Germination rate of seeds subjected to aging was well correlated with emergence in reduced tillage systems. Anchorage force of seedlings was positively correlated with tolerance to flextine cultivation. Our results suggest that choosing existing and developing new cultivars tolerant to physical weed control tools, untilled soil, and organic management may improve organic squash production in Michigan."--Page ii.