Tractor spraying soybeans with herbicide oticki/iStock/Thinkstock
SPRAY WITH CAUTION: Off-target drift of postemergence herbicides is always a risk.

Preventing ‘post’ herbicide drift risk is a fast-rising issue

Crop Tech Update: Drift risk of dicamba and other ‘post’ herbicide formulations warrants extra caution. Dusty plants warrant more sprayer water.

Dicamba drift risks not overstated

Earlier this year, American Agriculturist posted several stories about how to use the new dicamba herbicides, noting the critical importance of proper application and drift control. Several complaints were received, suggesting the topic was “overkilled.”

Yet this summer the Arkansas Plant Board voted to ban the sale and use of dicamba in that state. At least 242 complaints in 19 counties linked to dicamba damage to non-target crops have been filed with that board this year, according to GMWatch. Missouri is considering legislation for heavy fines on farmers misusing the products. “Misusing” includes allowing drift to happen.

The new dicamba formulations are labeled for postemergence use on dicamba-tolerant soybeans. Conventional soybeans, vegetables and fruit crops are vulnerable to drift damage. As Mark VanGessel, University of Delaware Extension weed specialist, points out, you still have to use common sense to avoid potential off-target movement.


Do low-rate ‘post’ herbicides need more water?

Dust can reduce weed absorption of contact herbicides such as glyphosate. So when it settles on weed leaf surfaces, it can cause glyphosate to bind to those clay particles and reduce plant uptake, especially on weeds with more waxy surfaces such as the nightshades and lambsquarter.

University trials in Wisconsin also found that adjuvants (ammonium sulfate, a non-ionic surfactant, and an organosilicone surfactant) weren’t able to completely overcome the effect of dust.

Be mindful of how soil disturbance (from in-orchard activities, from road traffic) affects dust production.

Make glyphosate applications in advance of periods when dust production may be heightened.

Sprinkler irrigation may be able to remove some of the dust from leaves. Glyphosate applications should be made after weed leaves have dried and before more dust can be deposited.

Source: Washington State University


Enlist for 2018?

EPA approval of Enlist Duo herbicide opens the option for use on 2018 corn and soybeans. It’s a combination of 2,4-D choline and glyphosate, and features Colex-D technology, which provides near-zero volatility, minimized potential for physical drift, low odor and improved handling characteristics.

As Damon Palmer, Mycogen Seeds general manager, puts it: “We’re excited to be the first national seed company to deliver these options for 2018 planting.” Corn hybrids with the Enlist trait will be stacked with PowerCore or SmartStax insect protection technology.

Enlist Duo is currently registered for use in 34 states, including New York. But it isn’t yet labeled for New England states.

Source: Mycogen

TAGS: Corn Herbicide
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