Weed resistance and the use of dicamba in corn and soybean operations was a hot topic at Commodity Classic 2017. During one of the educational sessions titled, "Taking Weed Management to the Next Level," some tips were given in regards to using dicamba to fight weeds.
1. Farmers need to educate themselves about the labels on dicamba products. It's important to note that the U.S. Environmental Protection Agency has approved the use of dicamba but only on a probationary two year period. This makes it especially important that producers and sprayers follow the label instructions when it comes to applying it.
2. Follow good stewardship practices.
3. Dicamba was touted by two growers who used the herbicide in 2016. However, producers still have to use good weed management practices. Don't rely on dicamba as the only weed killer.
4. Pay attention to the wind speed and direction. Don't apply if wind is less than 3 mph; 3 to 10 mph – is the optimum application conditions provided all other application requirements on label are met; >10 to 15 mph – do not apply when wind is blowing toward non-target sensitive crops; >15 mph – do not apply.
5. Ammonium sulfate can not be used even in hard water situations. This is because Ammonium sulfate can increase the volatility of dicamba.
6. Be aware of what neighbors have planted. Don't spray near sensitive plants.
7. Communicate: Don't have unknowns when you go to the field, talk to other growers. Know what chemicals are available and always have a plan!
8. Use the phone number on the label to report any weeds coming up when using dicamba.
9. Do not apply if rain is forecast within the next 24 hours following application. Do not apply during temperature inversions.
10. Be sure to include buffer zones. When “sensitive areas” are downwind from the site of application, a buffer between the last treated soybean row and the sensitive area must be maintained. The recommendation is if you use 22 oz then a buffer of 110 feet; Or 44 oz means a 220 feet buffer. Buffers can include a paved or gravel road or agricultural fields that are planted in corn, Xtend soybeans, sorghum, proso millet, or small grains.