July 06, 2025

6 tips for scouting fields

MARKLE, Ind. — Scouting is an important way for farmers to detect weed pressure in their fields, and it’s never too early to start.

Syngenta shared six tips for making the most of your scouting trips.

1. Pick the best walking route. For square and rectangular fields, an M-shaped pattern will be the most beneficial. For irregular shapes, ensure you cover a representative amount of the field.

2. Keep in mind that you can’t judge the weed population of an entire field by what you see on the edges.

3. For larger fields, you will likely need to split the area into smaller parts. This helps ensure you have the most accurate results, even if population data differs from one section of the field to another. Note the weed species you see, their locations in the field and the degree of control achieved with your current program and past herbicides.

4. Weed populations can be split into 4 categories, which can help determine your control options:

• Scattered — Occurs when there are not enough weeds to cause yield loss, but the population will produce seed and can increase the weed seed bank if left uncontrolled.

• Slight — In this case, yield loss is unlikely but possible in areas where pressure is heavier. The population is considered slight when there is one weed in every three feet of row.

• Moderate — At this point, yield loss is likely unless an effective management program is used. Moderate pressure is an average of one weed per foot of row. You may also see spots with severe populations.

• Severe — With this level of weed pressure, yield loss will undoubtedly occur unless effective control strategies are utilized. For broadleaf species, more than one weed per foot of row constitutes severe pressure. For grass weeds, it's three plants per foot of row.

5. Use your findings to determine which weed control measures are right for your fields, both this season and next.

6. Scout early and often. Then use that information to plan your weed management program accordingly.

Chad Threewits, a Syngenta agronomic service representative in Indiana, encouraged farmers to use multiple modes of action in order to tackle herbicide resistant weeds.

“For example, we may recommend something like Acuron herbicide on corn, where we’ve got four active ingredients and three sites of action,” he said. “That’s an example of putting our best opportunity out there to maximize weed control.

“On soybeans, (we may recommend) something like Boundary herbicide followed by Prefix herbicide or Flexstar herbicide, mixing those products in with the different trait packages.”

It’s all about mixing the best tools available in the tool box to achieve the best control possible, Threewits said.

For more tips, visit www.knowmoregrowmore.com.