2000 Annual Report for FS00-113
Developing IPM Practices for Sweet Potatoes in Mississippi
Summary
Mississippi’s acreage in sweet potatoes—10, 675 acres—is third in the nation after North Carolina and Louisiana. Production practices and habits are still relatively new among Mississippi farmers as is familiarity with pests and their management.
Much of the crop damage is in late season after the effects of the soil insecticides have dissipated and prior to harvest. It is not uncommon for fields to yield a 20 to 40 percent cull rate in some years, primarily because of soil insect feeding damage. The high value of the crop still makes it economical to grow even with these losses, but reduction of losses to below 15 percent would reflect tremendous savings and increased profits.
In this project, the producer intends to identify the major insect pests of sweet potatoes in Mississippi, devise sampling plans and formulate management plans. The goals of the project are: 1.) Test a non-pesticide off-season treatment for soil pests by flooding a field during the off season to kill soil pests and comparing the results with a field treated in the conventional manner, 2.) Develop insect scouting guidelines for thresholds of sweet potato pests, 3.) Coordinate pesticide application with adult emergence, particularly prior to oviposition.
The identification of pests and understanding of their life cycle is essential to reducing pesticide applications. Many of the soil pests of sweet potatoes emerge as adults in the spring, lay eggs and die. In order for pesticides to effectively reduce these pests, the producer intends to target adults prior to oviposition in the crop, applying effective adulticides/ovicides in a timely manner to break the cycle. If this can be accomplished then pesticide load, especially soil applied preplant applications may be reduced or eliminated.