A year ago, Bill Johnson said he would provide management tips for new 2,4-D formulations on 2,4-D-tolerant crops and new dicamba products for dicamba-tolerant soybeans once the systems were launched commercially. The Purdue University Extension weed control specialist kept his word.

Here are his comments regarding three different products that are in various stages of entering the marketplace.

• Enlist Duo in Enlist system. Dow AgroSciences has a label for Enlist Duo over 2,4-D-tolerant corn and soybeans. The product is a new formulation of 2,4-D that has very low volatility.

What Dow AgroSciences doesn’t have is import approvals from China for corn or soybeans. Spokespersons expect approval for corn first. But the company won’t implement a full launch of Enlist Duo on 2,4-D-tolerant corn now. Expect limited use of Enlist Duo by corn growers who can use their crop as livestock feed. Use of Enlist Duo in soybeans will be limited to seed producers.

“Since the company isn’t making a full launch, there isn’t much to say,” Johnson says. “We will provide suggestions for using that system when it’s fully launched.”

• XtendiMax in Xtend system. Monsanto has necessary approvals and is launching XtendiMax for dicamba-tolerant soybeans. “The most important thing is to make sure you understand the label for XtendiMax on Xtend soybeans,” Johnson says. “Know when you can spray and when you can’t spray based on the label.”

Individual states issue labels after the federal label is approved. States can add additional qualifications. Indiana is in the process of classifying XtendiMax from Monsanto and Engenia from BASF as restricted-use products. However, that likely won’t be in effect by the time spraying season arrives. They can still be sold as nonrestricted-use products this year, Johnson says.

The Office of the State Chemist will have employees spot-checking for proper applications, Johnsons says. Anyone caught not applying according to the label will be subject to fines.

“The problem in the eastern Corn Belt is that even in rural areas, there are many houses on most roads,” he observes. “Applications will need to follow the label carefully."

The label includes setback requirements from specialty or nonspecialty sensitive crops, wind speed limitations, and much more.

• Engenia in Xtend system. BASF launches Engenia, also a dicamba-based product for use over dicamba-tolerant soybeans. Representatives say it’s a new, less-volatile dicamba salt.

Many of the same restrictions about setbacks on the XtendiMax label are also on the Engenia label, Johnson says. Setbacks are buffer areas not treated with dicamba herbicides.

“This may be a situation where injection systems play a role,” he says. “It might allow you to spray a different herbicide combination where you can’t spray a dicamba-based product without making a special trip.”

Both XtendiMax and Engenia can be applied with only one spray nozzle. There are currently no tankmixes approved for either product. It’s likely that only specific tankmixes will be labeled by the time the season begins, Johnson notes. You can’t apply AMS with either product.

There are differences between the labels for XtendiMax and Engenia, Johnson observes. XtendiMax can’t be sprayed at wind speeds under 3 miles per hour. Engenia can be applied then as long as there isn’t a temperature inversion.