Mixed pesticide sprays are useful in crop production. Growers can select specific alternative pesticides that target specific pests on the crop, mix them, and apply all at once. Sometimes, pesticides work together and achieve greater efficacy. In addition, spraying one time as opposed to spraying twice or more is efficient and time-saving.
However, you must know what you are doing when you mix pesticides. First, identify the pest problem and then select the best solution. If there is more than one pest problem and the second pest requires a different chemical, you may be able to mix them.
You also need to know the details of the pesticides you are using. What do they kill? What is the mode of action (MOA)? What is the formulation? These are just a few of the questions that need to be answered.
Some pesticides work together, as I mentioned above. For instance, greenhouse growers combine azadirachtin and Beauveria bassiana to control summer insect pests such as thrips and aphids. This combination results in potentiation, meaning one compound enhances the activity of another.
Aphids and thrips grow so quickly in the summer that Beauveria is unable to penetrate them. Beauveria is a fungus that penetrates the insect and kills them. Azadirachtin is a growth regulator; thus, it slows down their development, allowing the fungus to penetrate and do its job.
Entomologist and integrated pest management specialist, Dr. Raymond Cloyd’s outstanding research at Kansas State University proved this. He is a phenomenal entomologist who works with greenhouse growers.
Years ago, a cover spray consisted of one chemical that killed pretty much everything. Today, we have many alternative pesticides that have safer (for humans) modes of action and are more targeted to specific pests.
Years ago, growers would spray regularly with a cover spray, keeping everything clean of all pests. Today, we inspect crops to determine the problem first and then determine the appropriate course of action.
We try to kill just the bad guys and leave the good guys (predators, parasites, and others) to grow and help with the crop.
I only hope that the company spraying the trees in Billings was using good pesticide strategies and not just spraying because something might happen.