Plant Talk |
CAUTION:The information and recommendations in this article are applicable to Harnett County, NC and may not apply in other areas.
CHOOSING AND USING PESTICIDES, 07/04/97
Pesticides are a valuable tool for gardeners as well as farmers, saving us many hours of work, and keeping our plants healthy. However, many of them are also extremely toxic chemicals which, if used incorrectly, can harm ourselves and our environment. Therefore, it is important to use them wisely.
Generally, the pesticides used by home gardeners fall into one of three categories. Herbicides kill plants (preferably weeds and not roses), insecticides kill insects, and fungicides control diseases. So the first step in choosing a pesticide is identifying the problem.
If your dogwoods or crape myrtles have a white powdery coating on the leaves, the problem is caused by a fungal disease called powdery mildew. You can apply Sevin until the pumpkins get ripe, but it will not solve the problem because Sevin kills insects.
Secondly, specific pesticides control specific pests. Contrary to popular belief, Sevin does not kill all insects. On tomatoes, for example, Sevin will control fruitworms, but not spidermites and apids. The latter two must be controlled with another product such as an insecticidal soap. As another example, 2,4-D does a great job of controlling dandelions, but not crabgrass.
It is also important to realize that pesticides cannot be used on just any plant. If the insecticide you bought says it is for lawns, you should not use it in your vegetable garden. This is critically important, because using a pesticide on the wrong plant could kill it. In the case of edible plants, such as tomatoes, it could even leave toxic residues on the fruit.
Since pesticides can be toxic, care should be taken while using them. At a minimum, it is a good idea to wear a long sleeve shirt and long pants, and a good pair of chemical resistant gloves. I am not talking about gloves for dishwashing, but the heavy duty kind you can find at the hardware store (usually made of neoprene or nitrile). Wearing gloves reduces your exposure dramatically.
So first we have to identify the problem, then select a pesticide which controls that problem on the specific plant.
As mentioned in previous columns, you can bring me a plant sample if you need help identifying a problem. As for the rest of the information you need, it is right there on the pesticide label. By law, every pesticide label has to include certain information including where it can be used, what it controls, how to use it, and what safety precautions to take. It also will explain other precautions such as how long to wait before reentering the area or harvesting the crop, as well as storage and disposal information.
The pesticide label will also contain one of three "signal words", which will help you determine its toxicity. The word "Caution" indicates the lowest level of toxicity, followed by "Warning", then "Danger". Pesticides in the "Danger" class can kill you if you ingest less than a teaspoon. This is useful information when selecting pesticides, particularly if you have children.
If you have never looked closely at a pesticide label, you may think it is written in a foreign language. But reading it closely is worth the effort, because the information could save you money, or even keep you from hurting someone. If you need help selecting a pesticide, or understanding the instructions, feel free to give me a call.
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