PRIMGHAR, Iowa — There are times when pests like insects, diseases or weeds keep our lawns, gardens, trees and crops from growing as well as we would like or need. For crop producers, the use of pesticides can be very profitable at times. For many homeowners, having a lawn that has dead spots or trees that die prematurely might not be acceptable. Pesticides can help us manage these situations in many cases, with minimal risk if they are used properly.

Every year, Iowa State University Extension and Outreach trains thousands of farmers and commercial pesticide applicators on using pesticides safely and determining when to use or not use pesticides. In fact, this winter I trained over 1,500 Northwest Iowa private pesticide applicators myself, even with COVID making it more difficult. In the past two years, there has been a focus on pesticide stewardship, wildlife conservation and pesticide use, disposal of unused pesticides, recycling containers, responding to a pesticide spill, reducing risk to water, opportunities to learn of new technologies to reduce the exposure of pesticides to the applicator, plus specific examples of making a “treat” or “don’t treat” decision.

Iowa’s pesticide applicator laws are some of the strictest in the country. In Iowa, if you are applying pesticides for money (a “commercial” pesticide applicator) or are using a restricted-use pesticide on your own farm or acreage, you need to be a licensed applicator. To become licensed to apply these products, you first have to take and pass tests offered by the Iowa Department of Ag and Land Stewardship. After receiving this initial three-year certification, applicators have two options for renewing that license. Applicators can take another test in three years or attend a two-hour continuing instruction course offered by ISU Extension and Outreach every year. Most private pesticide applicators choose annual educational meetings, which I believe helps them continually get better as applicators. Although accidents can occur, we have documented evidence that these producers are doing a better job protecting themselves and the environment around them when they use these pesticides. The training helps!

Homeowners often use pesticides, too. Rarely are they trained on how to use pesticides like those who incorporate pesticide use in their business operation, but the basics are the same. Here are five keys for safe use of pesticides at home.

1. Always read and follow the label directions. These labels tell you how to mix, how much to spray, what personal protective equipment you need to wear, and other hazards to watch for. The label is a legal document – you must follow it. Read the entire label before you use any pesticide.
2. Be aware of sensitive areas. Are there pollinators nearby that could be sensitive to an insecticide you are using? Remember that bees are most active during the heat of the day, and less foraging occurs in the evening. So, if you need to use an insecticide, reduce risk by applying when they are less active. Also think about sensitive plants that might be located in your yard – or the neighbors.
3. Every time you use a pesticide, know the wind speed and direction it is blowing. Small droplets move with the wind, so know which direction it is blowing and what could be in the zone of movement. The label sometimes has specific requirements for the maximum wind speed during application.
4. Keep spray nozzles close to the ground. If it is on a spray boom the height needs to be high enough to get a good spray pattern across the boom width, but a lower nozzle height reduces drift risk.
5. Use the lowest spray pressure your applicator can apply while still getting good coverage for your pesticide. Low pressure gives us larger droplets and has a much lower drift risk. Increasing pressure does NOT force the pesticide to the target faster, it just creates smaller droplets that can drift a lot worse.

Using pesticides can be quite safe if used properly. Iowans who apply them as a part of their business are the best trained applicators in the country. Anyone who uses pesticides without reading and following the label increases the risk. So, always read and follow label directions!

— Joel DeJong, Field Agronomist
Iowa State University Extension and Outreach

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