Beware of Plant-Back Restrictions When Making Late Burndown Applications

Dino Miller, GreenPoint AG  

Mother Nature is throwing us a big curveball so far in 2018, as precipitation levels have been much higher than the average for this time of year. As the “Departure from Normal Precipitation” map from the NOAA Regional Climate Centers pictured here1 shows, Arkansas and large portions of Louisiana and Mississippi have received much more rainfall than normal. Precipitation is also higher than normal in the surrounding states of Tennessee, Kentucky and Missouri.
In a typical growing season, many farmers in the southern part of GreenPoint AG’s service area apply their burndown application by ground rig as early as mid-January. But conditions have been so wet this year that most burndown treatments are just beginning now, and many farmers will be forced to incur the additional cost of aerial applications because it’s too wet to drive into the fields.
A concern with late burndown applications is that there’s a much shorter amount of time than usual between spraying and planting. Whether you’re planting corn, soybeans, rice or cotton, there are a number of burndown herbicides that have plant-back restrictions. This means it’s important to look at your weed management plan and make changes if necessary to avoid applying herbicides with residuals that could impact your spring crop. If you don’t identify the herbicides ahead of time that could impact your crop, you could cause damage or be forced to plant a different crop altogether.
Plant-back restrictions vary from crop to crop and weather conditions are changing week by week, so it’s best to call your local GreenPoint AG representative to make sure your weed management plan is kosher with the crops and traits you’re planting.
If there is a positive side to this spring’s weed control efforts, it’s that weed pressure is generally lighter than normal due to the dry fall we experienced. That being said, weeds like primrose, mustards, henbit, marestail (horseweed) and Italian ryegrass still need to be controlled prior to planting.
When targeting these weeds, it’s important to include the right herbicide and adjuvant package in your tank mix to achieve the best efficacy possible. Here’s a list of some of the products we recommend for burndown applications:
  • Cornerstone® 5 Plus and Roundup PowerMax® herbicides are two well-known glyphosate products on the market and they continue to provide good burndown results on a wide list of broadleaf and grassy weeds. A number of troublesome weeds like marestail and Italian ryegrass have developed resistance to glyphosate, however, so it’s important to also incorporate herbicides into your burndown program that have a different mode of action to control these and other resistant weeds.
  • Section® Three herbicide is compatible with glyphosate and provides good control of Italian ryegrass and other annual and perennial grassy weed species.
  • Sharpen® herbicide provides broad-spectrum control of more than 70 of the toughest broadleaf weeds, including ALS-, triazine-, and glyphosate-resistant biotypes.
  • Sterling Blue® herbicide, a dicamba formulation, controls or suppresses a wide range of broadleaf weeds, woody brush and vines, including tough ALS- and triazine-resistant weeds like waterhemp and kochia.
  • Class Act® NG® adjuvant is specifically formulated to meet adjuvant and ammonium sulfate (AMS) requirements for glyphosate-based herbicides. It offers an easy-to-use formulation that combines AMS for water conditioning, a nonionic surfactant, a crop-based adjuvant system and an antifoaming agent in a convenient liquid premix.
  • InterLock® adjuvant is a crop-based adjuvant that improves spray deposition on intended targets and reduces spray drift. It is also a canopy-penetrating agent.
  • Destiny® HC adjuvant increases penetration of waxy cuticle and leaf canopy. It is designed for use with herbicides that recommend a methylated seed oil (MSO), or crop-oil concentrate (COC) like Section® Three, Sharpen® and Sterling Blue® herbicides, but it is also compatible for use with glyphosate.
  • StrikeLock™ adjuvant is a high surfactant oil and InterLock® adjuvant premix that can be used with herbicides that call for a COC or MSO.