Spraying Tips for Fall-Applied Soil Active Herbicides

September 1, 2021

Fall-applied Group 14 and 15 herbicides are a great way to get a jump on early season weed pressures next spring. Tom Wolf, sprayer expert at Agrimetrix and Sprayers 101, provides some useful tips for spraying Group 14 and 15 products like Valtera™ and Fierce® in the fall.

Manage trash effectively

Good straw spread is essential when using fall-applied Group 14 and 15 products. “They do their job by controlling weeds prior to emergence, so job number one is ensuring the spray reaches the soil, and the number one barrier in the fall is harvest residue,” Wolf explains.

If your spreader hasn’t produced even straw spread, consider a heavy harrow application to even out the residue so your spray reaches the soil. This applies to any surface debris that may intercept the herbicide spray, including additional weed growth that may occur after harvest. “Any debris or plant growth that may prevent the spray from reaching the soil can impact herbicide performance,” Wolf says.

Use the right water volume

When considering application parameters, water volume is the most important tool you have to ensure effective weed control. “More water is usually better for getting through more trash, so a minimum of about 10 gallons per acre is appropriate for products like Valtera and Fierce,” says Wolf.

Choose a coarser spray

When setting spray nozzles, select based on your individual residue levels. Remember soil active products work in the soil so reaching the soil is job one. “Fall applied products are distributed in the soil with moisture from spring melt or precipitation, so the size of the droplet in which they arrive at the soil is less important. That’s actually a good thing—we can apply a coarser, low-drift spray, which opens up some hours in the day for spraying, even under windier conditions,” Wolf says.

See more tips from Tom Wolf by watching the video below.

For more information on fall-applied soil active herbicides, visit Nufarm.ca/kochia, contact Nufarm at 1.800.868.5444 or your local Nufarm Territory Manager.