Back in the 1990’s there were good farmers who didn’t like Pursuit herbicide. When Roundup Ready soybeans were first released, those same guys didn’t like Roundup either. What they didn’t like was that now the best, most meticulous farmers (namely them) didn’t stand out any more. Everyone had good weed control.
If you’re one of those good farmers, you have a chance once again to shine. Roundup resistant weeds have taken over some parts of our country and are spreading quickly in other areas. Here are a few keys to help you make your fields the envy of the neighborhood.
Just like in the conventional soybean days, the residual herbicides are going to be the biggest difference maker between the farmers with excellent weed control and the guys who seem to be in the sprayer all summer long. If you didn’t put down a pre-emerge herbicide this spring, chances are you already know what I’m talking about here. That said, there are still a few residual products you can apply with your post-emerge treatment to help you out through crop canopy.
RESIDUAL-ONLY HERBICIDES (won’t kill anything that has emerged)
- Warrant – This has the same active ingredient as Harness. Good residual on grasses and smal- seeded broadleaf weeds like the pigweed species and lambsquarters.
- Outlook – Another decent product with similar control to Warrant.
- Dual – Good residual on grasses with slightly less activity on the small-seeded broadleaf weeds than the other two herbicides listed above. Dual is still a good choice to extend your residual.
If you planted Liberty Link soybeans this spring, I believe you made an excellent choice to give you the flexibility to use Liberty for weed control. Liberty is quite a bit different than Roundup in the fact that it doesn’t translocate through the root system like Roundup can. Liberty sometimes gets a bad rap for the fact that it needs more water (15 gallons is better than 10) and more spray pressure (40+ PSI helps improve coverage) than Roundup does. However, Liberty is highly effective at controlling Roundup resistant weeds, especially when you spray weeds that are 2 to 6 inches tall.
If Liberty or Roundup aren’t enough to kill all the weeds on your farm, below are some options. If you have lambsquarters, Harass (generic Harmony) is best and costs less than $1 an acre. For waterhemp or palmer pigweed, Flexstar is best, but since it can only be used once per season, Cobra may be needed on a second pass. For ragweed, nothing beats FirstRate, but that, too, can only be sprayed once per year. Flexstar and Cobra are also good on ragweed if you need a follow up application.
RESIDUAL & BURNDOWN HERBICIDES (they kill both emerged weeds and weeds that would have emerged in the next few days)
- Classic – Cocklebur, Sunflower, Common Ragweed
- FirstRate – Common and Giant Ragweed, Morningglory, Cocklebur, Sunflower, Smartweed, Jimsonweed
- Flexstar – Pigweeds, Ragweeds, Morningglory, Hemp Sesbania, Carpetweed
- Pursuit/Raptor – Black Nightshade, Velvetleaf, Wild Buckwheat, Jimsonweed, Cocklebur, Sunflower, Smartweed
BURNDOWN-ONLY HERBICIDES (no residual)
- Grass/Vol. Corn Control – Don’t forget, volunteer corn is the biggest yield robber in soybeans weed for weed. Use Select Max, Assure II, or Fusilade. Spray twice, if necessary, as these products cost only $2 to $4 per acre, after rebates.
- Basagran – Venice Mallow, Yellow Nutsedge, Prickly Sida, Canada Thistle, Cocklebur, Sunflower, Jimsonweed
- Cadet – Velvetleaf, Pigweeds, Lambsquarters, Morningglory, Jimsonweed
- Cobra – Pigweeds, Hemp Sesbania, Carpetweed, Morningglory, Nightshade, Ragweed
- Harmony SG (or the generic Harass) – Lambsquarters, Smartweed
- Resource – Velvetleaf, Pigweeds, Common Ragweed, Prickly Sida