Maximize yields - winning weed control in conventional soybeans

By Scout Nelson

Farmers in South Dakota are choosing conventional soybeans over genetically modified ones for premiums, despite facing tougher weed control challenges. Understanding pre-1996 landscapes reveal that managing weeds in conventional soybeans is achievable with the right approach.

Field Selection is Critical: Before sowing, evaluate your fields. Avoid areas with high weed densities, herbicide-resistant weeds, or those known for hard-to-control species. Opt for fields with minimal weed issues to start on a positive note.

Start Weed-Free: Ensure your fields are clear of weeds through burndown herbicides or tillage. Glyphosate is a go-to for its non-residual action, but if using others like 2,4-D, dicamba, or halauxifen, heed the preplant intervals to avoid crop injury. Incorporating herbicides like metribuzin can bolster burndown effectiveness while also managing later-emerging weeds.

Prevent Weeds Before They Emerge: A robust preemergence herbicide program, ideally with two or three different herbicides, is essential. This diversity in your approach will help combat resistance and adapt to varying environmental conditions.

Effective Postemergence Strategies: Postemergence herbicides become necessary as weeds break through defenses. Target weeds when they are less than 4 inches tall for best results. Use a mix of graminicides for grass weeds and other specific herbicides for broadleaf control, including the PPO-inhibiting herbicides for persistent threats like kochia and waterhemp.

Non-Herbicide Control Measures: Besides chemical warfare, cultural practices such as selecting low-pressure fields, interrow cultivation, optimizing row spacing, and increasing planting rates can significantly aid in weed suppression. Hand weeding, though labor-intensive, prevents seed bank replenishment from uncontrolled weeds.

Utilize demonstration data on herbicides to tailor your strategy to the specific weed challenges in your fields. This integrated approach not only manages current weed issues but also reduces future infestations, ensuring your conventional soybeans thrive.

Photo Credit -istock-sandramatic