Weed Control: Early Option

Wet conditions this spring caused many farmers delays during plant-ing. But muddy and flooded fields did not catch everyone off guard. Farmers who applied a residual herbicide in the fall had a head start on controlling weeds come spring. A fall application involves applying a pre-emerge herbicide, such as Valor or Envoke, from late fall through the winter.

Henry Hensley, a farmer in Eudora, Ark., applied a residual herbicide early before planting 1,800 acres of corn. “This was my first year using a fall application. It was just a trial and error for me and I really liked it. I plan to do fall applications in years to come,” Hensley says. “Valor was a good choice for me.”

Pat Roberts, a crop consultant for Ag Vice Crop Consulting in McGehee, Ark., applied Valor on several fields in mid-November. “Even throughout the rains, we had total weed control through March. It wasn’t until April that we started to see a few grasses pop up,” Roberts says.

There has not been a better testament of fall residual applications than the sight of water-filled fields completely free of weeds this past spring. Scheduling a pre-emerge herbicide earlier in the season gives farmers more leeway if poor weather conditions occur. Fall residual applications gave farmers the ability to get in the field the moment the fields dried out. “When bad weather comes, you don’t want to get caught off guard,” Hensley notes.

“We had crazy weather all year – so much rain,” says Terry Denton, fertilizer manager at Gibson Farmer’s Co-op in Dyer, Tenn. “You really could see a night-and-day difference between the fields where we applied a fall residual herbicide and the ones where we didn’t.”

Tough Sell, Wise Decision
Although farmers are rapidly accepting the practice of fall applications, some are still skeptical. The idea of returning to a proactive approach to killing weeds, after years of using glyphosate as a burndown, is a hard transition to make. Many farmers do not like the idea of paying to kill weeds they cannot see. “To ask farmers to put money out six months in advance is pretty hard to do – it’s a tough sell,” Denton says.

Harsh weather conditions this spring helped convince farmers that a fall application is a wise decision.

“Once my customers see how products, such as Valor, control marestail, pigweed and other tough weeds, they are believers,” he adds.

Eliminate Safe Harbor For Troublesome Pests
More farmers are not only accepting the practice of fall applications as a time-saver in the spring, but also as a proactive approach to combating tough winter weeds and pests that rob soil of nutrients beneficial to crops. Pests such as the soybean cyst nematode and the tarnished plant bug can harbor in winter weeds, which makes it important to control the weeds in the fall before they become a bigger problem in the spring. For this reason, fall applications can increase a plant’s overall vitality.

Tough or resistant weeds are also becoming an issue across the South. Denton is encouraging his customers to use fall applications as another option in combating different types of resistant weeds. “Tillage is not the total answer for resistant weeds. It’s not always possible to do all of the spraying you would like to do, so it is best to be proactive and use a residual in the fall,” Denton says.

When choosing a pre-emerge herbicide for fall application, it is important to look for one with long residual control. Circumstances, such as crop price or weather, can lead farmers to change crops late in the season. Roberts finds that many of his customers need a product that gives them rotational flexibility as well. “If they can’t get the corn crop planted in a timely manner, then they can switch to soybeans. My customers really like the flexibility of Valor,” Roberts says.

Archer Malmo, who represents Valent, contributed information to this article.