Managing Weeds in the Field

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Weed management is one of the most crucial, worrisome, and sometimes one of the most expensive components of crop production. The common weeds that are found throughout North Carolina have evolved through many years of crop production to thrive in fields if they are left unattended. Growers now have pre-emergent herbicide options that can prevent weeds from ever germinating, as well as post-emergent herbicides to remove weeds once they begin to grow. Post-emergent herbicides are generally much more effective when the target weeds are small, and treating weeds that have grown to a larger size can cause herbicide resistance. While herbicides undoubtedly play a key part in weed management, they should only be one component in a program of weed management tactics. Your management program will be most successful when sensible herbicide use, crop rotation, crop competition, and cultivation are combined in a planned and coordinated program.

Crop rotation often allows for different herbicides to be used each year. This prevents the excessive buildup of certain weeds that may have not been targeted in a management program with only one crop. The rotation of herbicides will also help prevent the evolution of weeds that cause them to be resistant to herbicide control. This is important for a long-term management strategy that will undoubtedly save expense in the future. Some herbicides have rotation restrictions, so it is crucial to read the label and understand the restrictions before applying any herbicide.

Crop competition is often overlooked as a management tool, however, it is a proven method in preventing unwanted weeds in crop fields. The goal behind crop competition is to provide the desired crop with everything it needs to be successful such as proper nutrient management, moisture, quality seed, correct variety selection, etc. This helps to promote rapid growth, causing the row middles to become shaded and the roots to take up soil space quickly, giving weeds less space and sunlight they need to grow.

Many crops grown here in Sampson County such as corn, soybeans, cotton, and others do not require conventional cultivation practices in order to reach their maximum potential. However, if weeds are a problem cultivation can provide an effective method to remove them. Considerations should be made depending on the crop you wish to cultivate and how the plants are structured in order to prevent damage that can lower crop yield.

Intensive weed management plans that integrate multiple strategies prove to be cost-effective for growers here in Sampson County. For more information, contact the N.C. Cooperative Extension, Sampson County Center at 910-592-7161.