| Corn, Sweet - Perennial Weed Control |
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Perennial Weed ControlSeveral perennial weed species, including quackgrass, bindweed and milkweed, may be present in a corn field. The grass and broadleaf herbicides described above will have limited activity on these weeds. Use of glyphosate as described below can provide excellent control of these perennial weed species. glyphosate (Roundup 4S): 1 1/3 oz/gal (REI 12h, Group 9). Apply as a spot treatment BEFORE silking of corn. Do not treat more than 10% of the total field area to be harvested. Any crop plants receiving spray in the treated area will be killed. glyphosate (Roundup 4S): 2 qt/A (REI 12h, Group 9). Apply AFTER corn harvest to actively growing quackgrass 6” to 8” high. Wait at least five days and then plow. Do not plant subsequent crops other than those on the label for 30 days following application. Most effective on bindweed and milkweed at or after bloom. Formulated Mixes (Prepackaged Tank Mixes)In recent years, several products have come on the market as formulated combinations of herbicides which were often recommended in the past as tank-mix combinations of products purchased separately. Following is a list of some formulated mixes registered for use on sweet corn:
There are three questions that a grower or pesticide applicator should ask when deciding whether to use a formulated mix or the individual herbicide. (1) Which is less expensive on a per acre basis? (2) Which formulation is easier to apply? (Most pesticide applicators prefer to avoid wettable powders, for example) and (3) Is the ratio of the two herbicides in the formulated mix appropriate for the given field situation? For example, Bicep Lite contains 2/3 as much atrazine as Bicep and should allow growers a better opportunity to obtain good grass control without using more atrazine than is needed. Dual II, Bicep II, and Bicep Lite II are newer formulations which contain a safener. The safener is designed to improve the tolerance of corn to metolachlor in cold soils. For supersweets and “se” sweet corn, it is still highly recommended to wait until soil temperatures reach 60°F before planting. |
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