LSU AgCenter's Weekly Message

Pesticide Safety and Effectiveness Tips

It’s that time of year when we hold recertification meetings for private pesticide applicators. These are people who are certified to buy restricted use pesticides and use them on property they own or lease. They have to attend a meeting approved by the Louisiana Department of Agriculture and Forestry once every three years to maintain their certification.

I thought it might be a good time to review some basics of pesticide safety and effectiveness with you, too. These tips are related to protecting the pesticide applicator; the people, animals, and plants around where the pesticide is applied; the people who will eat the food from plants it’s applied to (as applicable); and the environment in which we live. They also affect whether the product is effective for the purpose for which it’s intended.

Note that when we say pesticides, people sometimes think just of insecticides, but “pesticides” also include herbicides, fungicides, miticides and other similar products.

One of the most important concepts related to pesticide safety is, “The label is the law.” Federal and state law require that we follow the directions on pesticide labels. This covers things such as using them only on plants, animals, or sites (as applicable) that the label allows us to use them on; wearing protective clothing specified on the label; not using a rate higher (or lower, when a range is given) than the label allows; and not using them more often or closer to harvest than the label says we can.

Another important concept is that the cause of a problem should be correctly identified before a pesticide is used. Oftentimes, when a plant looks “sick,” the cause is related to non-pest causes. Examples include stress from heat, cold, lack of water, or too much water; improper plant selection (e.g., plants not suited to our climate or how wet or dry or sunny or shady the site is); soil compaction; injury from string-trimmers; etc.

Likewise, there are many types of pesticides and many types of “pests,” and any given product is only effective against a relatively small subset of them. For example, if the cause of plant disease is a bacterial pathogen, a product that only has fungicidal activity isn’t going to help. Furthermore, not every plant pest problem can be helped with a pesticide, and sometimes once a problem is obvious enough that people notice it, it’s too late for a pesticide to do any good.

Before wasting money on something that isn’t going to help your issue, make sure the problem is diagnosed correctly. Let us know if we can help you with this.

Finally, it’s useful to know that companies are not required to prove that a product is effective on a particular insect, disease, weed, etc., before listing it on a pesticide label. Therefore, it’s important to have sources, such as the LSU AgCenter, from which to get research-based information about what products work well on what pests.

Let me know if you have questions.

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Dr. Mary Helen Ferguson is an Extension Agent with the LSU AgCenter, with horticulture responsibilities in Washington and Tangipahoa Parishes. Contact Mary Helen at mhferguson@agcenter.lsu.edu, 985-277-1850 (Hammond), or 985-839-7855 (Franklinton).