Soybean Weed Control Program
The Easiest Way to Control Roundup Resistant Water Hemp is to
Never Let It Come Up!
No-Till Program
November of year preceding soybeans apply 1.1 oz Cloak, 8 oz Metro and 4 oz Dicamba. Soil over 6.8 PH use 6 oz Tricor instead of the 1.1 oz Cloak. This will help control henbit, pennycress and marestail during the winter and early spring. Do not put this on until the soil temperatures are around 56 degrees. If the soil temperature is too warm, the Cloak will degrade too quickly and not give as long of control.
Two weeks before anticipated planting, apply 4 oz Authority XL. Don’t apply the Authority too early or it will wear out too quickly in the growing season. If the soil PH is over 6.8 PH, use 3.5 oz Authority First instead of Authority XL. The Authority XL has too much Classic in the formula to use on high PH soil. The Classic can really stunt the soybeans. Add 24D and/or glyphosate as needed. Alternatives to Authority are Valor XLT and Fierce. Fierce can be used on soil 6.8 PH and higher, Valor XLT cannot be used on high PH. (Add glyphosate and 24D as needed for the burndown.)
21 to 28 days after planting, use 32 oz Power Max (6# product) and 3 pints Warrant. Glyphosate does a much better job on small weeds. The Warrant is in the spray to provide another shot of residual to try to keep the waterhemp under control. This is also the best time to control volunteer corn if present.
Using this program should really help waterhemp control and cut down on the amount of leaf burner herbicides that are required. Leaf burners also burn the beans, taking about a week out of their growing season. They are also expensive to use and do not always do the job.
Till Program
Tillage will be used in the fall, rather than using a herbicide for winter and early spring weed control.
Plant the soybeans and immediately apply 4 oz Authority XL on soil that is less than 6.8 PH. For higher PH soils, use 3.5 oz Authority First. These herbicides cannot be applied to a field where the soybeans are emerging. They can stunt or even kill emerged soybeans. If the soybeans emerge before a herbicide application, a different plan will be used.
- Use 1 quart Prefix and 32 oz Power Max as an early post emerge. Prefix is metalachlor and fomesafen. Fomesafen is a leaf burner, metalachlor provides a residual herbicide.
- Or, use 42 oz Power Max and 3 pints Warrant at 21 to 28 days after planting.
If there are not two applications of residual herbicide, there is a greater chance that a later application of a leaf burner, such as Fomesafen, Ultra Blazer or Cobra will be needed to attempt to control the waterhemp.
Double Crop Soybeans
After planting the double crop beans, spray as soon as possible after planting with 32 oz Roundup Power Max and 3 pints of Warrant. The Warrant helps give residual for water hemp control and does not tie up easily in the wheat stubble. If there is water hemp present at spraying time, add 1 oz of Sharpen to burn them down. As always with Sharpen, use a flat fan or turbo tee nozzle, 20 gallons of water with a spraying pressure of between 30 and 40 psi, and add methylated soy oil at 1 gallon/100 gallons of water. If the beans have emerged, do not use Sharpen. Sharpen will kill emerged soybeans!