South Carolina tobacco producers face tough challenges in weed management. Annual grasses, pigweeds, sicklepod, yellow nutsedge and morningglory complex, common cocklebur, and eclipta are the most common and troublesome weeds in South Carolina tobacco fields. Weeds compete with tobacco for water, nutrients and sunlight. While low levels of weed infestations may not reduce tobacco yield, late season weeds can interfere with harvest and reduce leaf quality. A successful weed management plan will use multiple production methods to keep these weed populations low.
While options for weed management in tobacco production are limited, adequate weed control can be obtained with proper herbicide selection and application. Tillage and seedbed preparation should eliminate all emerged weeds prior to planting. The transplant bed should be smooth and level at the time of preplant incorporated (PPI) herbicide application to insure even application across the field. This will allow for uniform incorporation of PPI herbicides with tillage. Activating rainfall or irrigation is needed for optimum preemergence herbicide activity and weed control. Timely shallow cultivation (no deeper than two inches) when weeds appear after crop establishment will provide season long weed control. Deep cultivation only brings more weed seeds to the surface prolonging weed interference. Use of specific herbicides depends on the weed spectrum of your field, economic considerations and your application system. Consider your situation and tailor a weed control program to your needs. The growers' guide will guide you in the decision making process.
Always read and follow label directions, as labels frequently change. A 2007 survey indicated that 57% of the acreage was treated with Prowl, 32% with Command and 55% with Spartan. The following were results of several on farm tests using Spartan herbicide for weed control.