Full Spartan Label to Allow Fall Application
Full label approval of Spartan (sulfentrazone) is expected in time to permit application this fall, a treatment option which would allow producers to control the first flush of weeds next spring on fields planted to ‘flowers.
Many sunflower producers are already well-acquainted with using Spartan for controlling annual small-seeded broadleaf weeds, including kochia, pigweed, lambsquarters and nightshade. The 2003 growing season marked the fifth year that Spartan received a Section 18 emergency registration label by the Environmental Protection Agency, to be used in sunflower for controlling kochia.
The full label will allow Spartan to be applied in the fall, a beneficial option for minimum and no-till sunflower producers, permitting a wider window of application and a greater chance for moisture activation next spring. With full label approval, a four-month rotation interval to small grains will be allowed.
As many sunflower growers already know, recommended application rates for Spartan vary depending on soil type and organic matter. Sunflower has good tolerance to Spartan on different soils, from coarse to fine textured soils with organic matter from 1.5 to 3.5 % as long as producers follow use rate guidelines. The product shouldn’t be used on coarse textured soils with less than 1% organic matter.
“Coarse soils with low organic matter call for lower use rates. Higher pH’s, greater than 7.5, also enable a greater degree of activation than lower pH soils, but
moisture remains one of the key ingredients for successful activation,” says Sam Tutt, northern technical manager for FMC Corp, which makes Spartan.
Microbial activity breaks Spartan down in the soil, just like anhydrous ammonia. Thus, similar to anhydrous, Spartan should be applied in the fall when the soil temperature is less than 50 degrees down to about the five-inch soil depth. Soil microbial activity dissipates at this point, minimizing treatment degradation.
“The application concept is the same as anhydrous N,” says Tutt. “Apply Spartan right around freeze-up. Then the treatment will be available when weeds begin to germinate in the spring, and chances are there should be enough snow melt or early spring rain for product activation.”
Dual Magnum (s-metolachlor), a Syngenta product, has been labeled for preplant surface-applied, preplant incorporated, or preemergence application, providing control of most annual grasses and small-seeded broadleaf weeds in sunflower. However, the product currently is not labeled for use on sunflower in the fall. “I personally feel that it’d be a good application, but although we have a fall label for crops that include corn, soybeans, dry edible beans, and sugarbeets, we don’t have it for sunflower,” says Emmet Lampert, technical sales representative for Syngenta, Wimbledon, N.D. – Tracy Sayler
*Spartan application notes
• Crop injury may occur on soils with low organic matter (< 1.5%) and pH of 7.8 or higher particularly on calcareous outcroppings, and hillsides. Do not use on coarse-textured soils with less than 1% organic matter.
• If Spartan is applied two weeks or longer prior to planting, use higher rate in the appropriate rate range for the soil type.
• Surface-apply Spartan using ground equipment with a minimum of 10 gallons per acre.
• Agitation is very important in cold water (10 minutes suggested), preslurry is recommended.
• Spartan can be tankmixed with burndown herbicides and labeled sunflower grass herbicides. Do not reduce rates of tank mix partners.
• Spartan can be mixed with liquid fertilizer. Slurry Spartan with water prior to tank mixing with fertilizer or ammonium sulfate. (check for compatibility before mixing with fertilizer).
• Spartan can be surfaced applied without risk of photodecomposition or volatilization.
*See full label for complete application details, including recommendations in preparation for spring planting. Web site for FMC, manufacturer of Spartan: http://ag.fmc.com. Also see http://www.cdms.net, an online database of crop label information widely used by the crop protection industry.
Back to Weeds Stories
Back to Archive Categories