Understanding Dicamba: Part 2

 This is the second in a three-part series on using dicamba.
In preparation for growing season 2019, farmers in the Agtegra service area are probably wondering what has not changed when it comes to the three main dicamba products: XtendiMax from Bayer, Engenia from BASF and FeXapan from Corteva.
According to Brad Ruden, Agronomy Tech Service Manager for Agtegra, the good news is that the unique nozzles that must be used to apply dicamba are one of the things that have not changed. Farmers should check each individual company’s website for information on which nozzle should be used with each product and the pressure range.
“Ground speed should still be less than 15 miles per hour,” Ruden says. “Boom heights should be 24 inches above the target—whether that’s the ground or the crop canopy, depending on when spraying occurs.”
Wind conditions are very particular for spraying dicamba. Wind speeds must be between 3 to 10 miles per hour, and dicamba cannot be used when inversion conditions are present.
New Restrictions for 2019
There are some new restrictions regarding dicamba application for this coming growing season. All dicamba applications have to have at least 15 gallons per acre minimum.
“Growers should also be aware of newer products and tank mix partners to go with dicamba,” Ruden says. “Look at each individual product website to find the unique list of what is allowable.”
Ammonium sulfate has not been allowed in dicamba tank mixes in the past, but new this year is an increased emphasis on acidifying water conditioner in the spray tank with dicamba, because it will greatly increase the volatility in the tank mix.
“Another big, new change is the restriction on application timing,” Ruden adds. “The federal label says dicamba cannot be applied to soybeans any later than 45 days after planting, regardless of planting date, and must be completed prior to first bloom, so the R1 stage, beginning bloom.”
A new June 30 deadline for spraying dicamba has been added in South and North Dakota in 2019, again regardless of when planting occurs. With the wet spring this year, this deadline may be worrisome for many producers.
“With this year’s weather, there are large areas of fields that we aren’t going to be able to get into as early as we want this spring,” Ruden says. “Agronomically, farmers should wait for correct soil conditions to plant. Crops do better when we wait until correct soil conditions are present. With later planting, the application window for dicamba is likely going to be compressed as well.”