Ag notes, April 25

Avoiding herbicide resistance 

 Herbicide resistance has become an important issue to consider when making weed management decisions. Weed resistance can and has occurred to several products in recent years.

The potential for weed resistance to develop increases with continued use of herbicides that have similar chemical compositions. So, herbicide use should be monitored and production practices implemented to prevent and reduce the potential for resistance to develop.

A key to avoiding herbicide resistant weed populations is prevention. Here are some management strategies to consider in preventing and dealing with herbicide resistant weeds.

• Scout fields regularly and identify weeds present. Respond quickly to shifts in weed populations to restrict the spread of the weeds.

• Select a herbicide based on weeds present and use a herbicide only when necessary.

• Rotate crops. Crop rotation helps disrupt weed cycles and some weed problems are more easily managed in some crops than others.

• Rotate herbicides. Avoid using the same herbicide or another herbicide with the same mode of action for two consecutive years in a field. Remember that it is possible for a herbicide used in one crop to have the same mode of action as a different herbicide in another crop.

• Apply herbicides with different modes of action as a tank mixture or sequential application during the same season.

• Combine other weed control practices, such as cultivation, with herbicide treatments where soil erosion potential is minimized.

• Clean tillage and harvest equipment to avoid moving weed problems from one field to another.

For more information on weed management, contact the Boyle County Cooperative Extension Service.