Pest management is getting more complicated

It’s not just you, everyone will agree that pest management is getting more complicated. In the old days, we often just selected the best pesticide, the most efficacious or the least expensive from multiple options. The pesticide was often very broad spectrum and very effective.

The use recommendations were simple back then, maybe a timing restriction or a do not use with a certain adjuvant type or rate that could reduce performance. But just using one pesticide like a glyphosate over and over was the quickest way to select for resistant pests. It worked and now we have to deal with difficult-to-control resistant pests with fewer and generally less potent pesticide options.

Diversity needed for pest management

When pests are resistant to the most commonly used pesticides, the media calls them ‘super bugs’, ‘super weeds’ or something similar. The key to managing these super pests is always to use diverse tactics, so called best management practices (BMPs).

BMPs for resistant pests usually include an array of chemical, biological, cultural and mechanical practices. However, if you are talking to a chemical representative, that diversity is going to be chemicals, applying different pesticides either sequentially or in a mixture. Chemical pesticides alone are not the best way to manage pest problems, but chemical mixtures are often the only practical solution when a grower calls on the ag aviator for help.

Selecting the best pesticide mixture

All experts now recommend using mixtures of pesticides with different modes of actions, but the number of pesticide options is running low in many markets. For example, a grower trying to control Palmer amaranth in soybeans and cotton has to throw the kitchen sink at it or they will be hand weeding to save the crop. Palmer already has evolved resistance to six different herbicide types and will quickly destroy the crop if unchecked. The situation is getting worse. Those resistance mechanisms often do not occur in the same weed but Palmer is interbreeding and a super weed with all of the mechanism will exist soon.

To know what to mix, growers need help from experts that know what resistance mechanisms are in the area or likely to be soon. Experts including chemical dealers, other applicators and manufacturing representatives are a great source of this information. Growers need to stay up-to-date if they want to stay in business. Ag aviators can increase the value of their services if they stay up-to-date. You have the great advantage of knowing what chemicals are currently being applied in your area and being able to see what is and what is not working.

The EPA approves many different pesticides. In your area, experts and the industry have worked together and limited the number of options to consider. If you select from that list, the problem of putting the best mixtures together is much simpler than trying to determine from all the theoretical possibilities. Extension bulletins will identify these mixtures and provide efficacy information on the best options.

Following label directions is more difficult the more pesticides you mix in the spray tank. Essentially the pesticide with tightest restrictions must be followed and that can be difficult to determine when you are looking at multiple product labels. Buying premixtures can make that task easier because the supplier has done that work for you and provided just one label to follow.

Selecting the best adjuvant mixture

Selecting the best adjuvants to maximize the performance of all the pesticides in the tank can be difficult. Often one pesticide label restricts a certain adjuvant type or rate that is needed for another pesticide. The most restrictive label directions must be followed.

A common issue is how much adjuvant to add. There is no point using full rates of a pesticide and only half the adjuvant needed to get maximum performance. Similarly, there is no point using full rates of adjuvants and only half the pesticide. Most surfactants are recommended at 1 to 2 qt/100 gal but are often used at half those rates even though surfactant cost is very low relative to the pesticide. With glyphosate, higher surfactant rates usually work better and increasing efficacy from 95 to 100 percent control could be the difference between a resistant weed setting seeds or not.

A customer once said, “No John, I am not adding additional surfactant. We are using a ‘premium’ brand and do not need any more according to my rep.” Well that customer had a tough-to-control weed and tried adding 2 qts/100 gal and smoked it. Neighbors noticed and asked him how he did it. So definitely use your adjuvant experience to help your customers. They will appreciate it.

We recognize customers are not always asking ag aviators for chemical advice, but you will add value to your business if you stay up-to-date on pest problems and chemical programs experts are recommending. You are not giving your customers the full service they need if you apply less effective pesticides and adjuvants just because they asked you to. It is not complicated to stay up-to-date if you pay attention to experts and monitor your applications.

For more information, contact John Garr at (765) 395-3441 or


Write a Comment

view all comments

Your e-mail address will not be published. Also other data will not be shared with third person. Required fields marked as *