By Lars Swanson
Memphis, Tenn.
• B.S., Chemical Engineering, Rose-Hulman Institute of Technology, Terre Haute, Ind.
• Marketing Portfolio Manager, DuPont Crop Protection.
• Worked for DuPont for nearly 20 years in operations and management roles.
• Grew up in eastern Iowa.
• Father of three children, husband to wife Nicole.
• Resides in Collierville, Tenn., near Memphis.
As producers in many parts of the Cotton Belt continue to plant cotton and corn, they are faced with a wide spectrum of insect pests that wind up attacking both crops. The situation became so bad in parts of the Mid-South last year that some producers wound up spraying as many as a dozen times in adjacent corn and cotton fields.
It’s a situation that requires a proactive attitude. But there are other factors to consider when evaluating the problem and then putting together a plan to cope with these pests.
The current weather and recent mild winter certainly contributed to the environment in which we find ourselves right now. Insect populations increased because of the warmer temperatures, and that, in turn, had an impact on the density of insect flights. In short, when we think about planting variables, we must realize that insect emergence and other factors will make every year different.
I don’t think we have learned everything that we need to know about insect patterns in this corn-cotton environment. In fact, because of the timing of the crop, I think we can learn something new just about every year.
There is actually a good news/bad news aspect to the corn-cotton rotation. True, corn planted behind cotton can have a positive impact on nematode control. Conversely, there are also insect populations that exist only in corn. The larvae will be present in the corn and will eventually come out and go through a cycle and basically disperse into other crops.
Corn also dries down into something that will be more attractive to the same insect, and those moths will likely end up in cotton. This migration into cotton develops when the crop has reached its fruit set position.
This is an all too familiar bit of advice, but producers need to be prepared for these insect scenarios and work with vigilance. You can’t approach this problem and be nonchalant about it. Work with your consultants and understand how insects migrate in a corn-cotton scenario. Make sure you understand the tools you need when it comes to a worm threat for both crops.
Let’s take a closer look at this insect environment for corn and cotton. With the changes that have occurred in crop protection products being used, and having the traits in crops that are primarily aimed toward lepidopteran and worm pests, we’ve had an increased emergence of secondary pest populations, such as plant bugs and stink bugs. Producers have battled these insects in the past by making numerous spray applications. Having said that, the insect population dynamics have changed, and producers’ approach to applications have also changed.
As we study the problem, some of the resistance we’re seeing in weed species is offering alternate host environments for these kinds of insects. It is an integrated system when we think about what insects are there and the alternate hosts that exist.
What about the flaring of secondary insect pests? This is a situation that occurs when conditions have to be ideal for specific insect populations to increase. Many of our companies have developed insecticides that can be applied and have an impact on beneficial insects. This allows for an improved insect control program and can prevent the serious flaring of pests such as spider mites.
In my opinion, we put ourselves in difficult situations when a pyrethroid is part of a farmer’s program. That’s when you might wind up with a flaring and have to fight it with other chemistries. I’ve heard entomologists such as Dr. Gus Lorenz of Arkansas talk about how more harm than good can occur by using a pyrethroid approach.
Our company (DuPont) has a new product called Prevathon that has demonstrated good activity in a cotton-corn environment and can help control worms in either crop where there is a residual being applied. This is a tool that can enhance the plant protection already in place. In some instances, we’ve seen yield increases approaching 150 to 200 pounds of lint in cotton with this product. Anything we can do to prevent multiple sprayings while taking advantage of the longer residuals is a plus for the farmer.
What’s the takeaway message here? Make sure the producer is working with his consultant or Extension specialist and find the best overall strategy for agronomics, including the crop variety mix. In the end, it’s always best to use products that offer the longest residual protection. That, in turn, will set up yield protection for the rest of the season.
Lars Swanson is DuPont Crop Protection’s insect control portfolio manager and is based in Memphis, Tenn. He can be reached at lars.d.swanson@usa.dupont.com or (901) 746-6029.