Currently, sweet potato acreage remains limited in Missouri, with local production far exceeded by public demand. Sweet potato is a sub-tropical plant and excels in warmer conditions. With changes in our climate resulting in more frost-free days and elevated carbon dioxide levels, production areas for sweet potato in more northern regions such as Missouri should be expanded.
However, among all major pests in sweet potatoes, weeds, especially weed occurrence during the initial 30-45 days after transplanting, are the greatest impediment to expanding production areas and optimizing yields. Our proposed research will take place on a local farm, and treatments will compare various combinations of cover crops and herbicides for early season weed management in ‘Beauregard’ sweet potatoes grown on raised beds. Fall seeded cereal rye and tillage radish will be compared to bare ground tilled areas prior to sweet potato transplanting in spring. Cover crops and winter annual weeds will be terminated with glyphosate and residual herbicides such as flumioxazin and metolachlor will be used to preclude early season weed competition. Post-transplant, metolachlor will be used in some treatments as an overlapping residual to prevent establishment of competitive broadleaf annuals such as pigweeds. This practice is used in Georgia and Louisiana but has not been explored in Missouri. Through the growing season, weed density and sweet potato coverage will be assessed, and weed biomass and sweet potato tuber yield will be evaluated upon harvesting. The overall goal of this proposed research is to promote sustainable weed management practices for sweet potato in Missouri and attract additional growers. Results will be summarized and presented at a cooperating producer’s farm to local vegetable farmers for consideration in adopting as production practices. MU Extension Horticulture specialists and specialty crop growers will be invited to participate in a Field Day for visual demonstration of each treatment. Surveys will be conducted to determine grower interest in the demonstrated research and assess the potential for adoption. An extension publication and peer-review publication will be prepared to broaden the audience reached.
Project objectives from proposal:
Based on the U.S. farm census of 2017, there were 1,503 farms producing vegetables, melons, potatoes, and/or sweet potatoes in Missouri. Therefore, the maximum estimated number of sweet potato growers, up to 1,503 farmers, could become aware of the multiple-approach for sustainable sweet potato production.
- Through the proposed workshop, an estimated 30 farmers will learn about integrating cover crops and single as well as overlapping residual herbicides for weed management in sweet potato production.
- It is estimated that 10 farmers will indicate that their understanding of developing sustainable production approaches can improve sweet potato yields.
- 5 growers will likely try the proposed approach on their farms.
A broader impact could be generated after the peer-reviewed journal article is published.