Target spot can make Southeast cotton and soybeans go south in a hurry

Sponsored by: BASF

Native Southeast States

Worst-case scenario: severe defoliation

Best-case scenario: Proactive protection for full-yield potential

The thing about target spot fungus in your soybeans or cotton is that it used to be “hit or miss,” but now it’s just “hit.”

2015: hit.

2016: hit harder.

2017: ???

What is sure is that during the 2016 cropping season, target spot was one of the most widespread and severe foliar diseases of cotton in Southeastern and Delta states. Several reports by consultants revealed sudden significant cotton defoliation within a couple of weeks from initial disease detection, and that contributed to a 400-600 lb/A loss of lint. This makes the economics of a fungicide treatment easy to see, with the fungicide application cost ROI being around 25 lb/A of lint.

When it comes to target spot, growers’ emotions are raw, and right on the surface — just like target spot itself on the leaves. Symptom development begins in the lower canopy with circular lesions, usually about 1/4” to 1/2” in diameter, with concentric rings (the “target”).

To the casual observer, a field may appear normal from a distance. But it can be a costly mistake not to inspect your plants underneath and up close, even down to the petioles, pods and stems that can also be infected by target spot.

Key environmental factors that favor disease progression include prolonged conditions (typically 5-7 days) of high relative humidity, or free moisture provided by rain or heavy dew plus warm temperatures. Several days of consecutive rainfall or irrigation will also increase the severity of disease development.

Unfortunately, some of the newest practices that favor high yields may also be creating some of the conditions for target spot. Growers control irrigation much better today, pushing yields by pushing water down the rows more frequently. But that same intensity of field management that is driving yields is also creating a high humidity environment, which target spot thrives in.

For more and more growers, nothing proves as effective on target spot as Priaxor® Xemium® brand fungicide. BASF Innovation Specialist Brady Reynolds recommends cotton growers look really hard 60 days post-planting (early fruiting before canopy closure) for a first application for cotton and an R2 application for soybeans. Experience has shown growers have to get on target very quickly to safeguard yields.

Dr. Bob Kemerait, professor of plant pathology at the University of Georgia, has studied target spot closely and has seen what it can do in cotton: “What is most remarkable about target spot is just how explosive the disease can be,” he said. “I don’t know if I’ve ever seen a foliar disease, unless it is a rust type disease, that can move as quickly in cotton. You see your first spots developing, and within three weeks after that, when conditions are favorable, you may have lost 60-70% of your canopy.”

With that much at risk, growers count on Priaxor fungicide’s disease control to deliver continuous protection, with more consistent performance for maximum yield potential.

Dr. Kemerait adds, “The other thing, especially for cotton growers we consult with in south Georgia who’ve had significant losses from target spot, is that they’re not going to wait until they find it. They are going to recognize that they’ve got high-yield cotton, they’ve got the conditions that favor the disease, had it in the past, and now they’re going to go ahead and spray preventatively.

“Though not the only fungicide labeled for cotton, Priaxor is our standard across the Southeast for control of target spot,” Kemerait notes. “Priaxor is especially desirable because the product allows us to deploy two modes of action, thus reducing our risk to resistance development.”

From ag universities to crop consultancies, and farmers with boots on the ground, the experts agree: target spot is not to be taken lightly. And before the going gets tough, go with the best: Priaxor fungicide.

Always read and follow label directions.

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