First, since it is called a residual many products can go on early along with burndown. Burndown can start as soon as frost leaves the field, which could be any day now.
Secondly, when it comes to soybean herbicides we have focused on burndown and the need to control weeds early. We mistakenly think that burndown is the residual and will carry us through to a crop Roundup application. Then it turns into 2 glyphosate treatments with one of them typically being an emergency because weeds are 8 to 10 inches tall. We experience a lot of disappointment and worse yet, yield reducing damage.
To solve disappointment or emergency application, apply a residual acetamide based product that provides longer lasting pre-emerge control for a host of weeds. The most important weeds to control at that stage, from planting to 12” beans, are: waterhemp, nightshade, pigweed, all small seeded broadleaves and all foxtails. We are not as worried about sunflower and velvetleaf, as they will come later and are much more easily controlled with Roundup. We have few, if any, pre-emerge weapons for sunflowers anyway. It is a the carpet of grass and continuous flow of nightshade that cause the greatest problems early.
Warrant Now Labeled Pre-Emerge for Soybeans.
New for 2013: Warrant TM herbicide by Monsanto is now approved for pre-emerge weed control on soybeans. It offers a low cost grass and small seeded broadleaf pre-emerge control using the most powerful acetamide available. It is the same active ingredient in Degree, Harness, Tripleflex, Surpass, and Keystone. You now have the same pre-power in beans as you have in corn at early application. We have great success wth 2,4D tank mix partners such as Authority First and Valor XLT for burndowns and residual for SOME broadleaves, but when it comes to grass, an acetamide is your best option by far. You can apply Warrant TM post-emerge up to canopy along with your Roundup as well. In fact, you can apply 2 or 3 pints at planting followed by another 2 to 3 pints maximum in-crop as a post application for cleanest beans possible. Warrant TM is also labeled on corn post applied for late season grass and small broadleaf control as a tank mix partner with Roundup. This proved to be a fantastic combination last year and will be the best value by adding an additional mode of action to your soybean herbicide program that you can’t get with just 2 shots of glyphosate year after year. That is what selects out for resistant weeds and that’s why WarrantTM is a great fit to help solve the weed resistance challenge in our fields today.
Contact your FSA for more information on Warrant TM and other products.