ISSUE 10   July 17, 2008


Weather extremes can place enormous pressure on growers and applicators to use pesticides in manners that violate label directions. This year’s weather has certainly been a case in point. With the replanting of some fields, many questions have been asked about the potential to replant different crops after herbicides had been applied to corn or other crops. However, residual pesticides greatly restrict the crops that can be replanted because of the rotational restrictions on the label. These restrictions are in place to protect the next crop from injury and also to ensure that the next crop does not contain illegal or elevated pesticide residues.

The consequences of not following label restrictions can be costly. For example, two or three aerial applicators were making late applications of a fungicide to wheat in Kansas. The fungicide had a 45-day preharvest interval, but applications were made too close to harvest. As a result, the wheat was at risk of having fungicide residues in the grain that exceed the level permitted by EPA. This has the potential to affect both growers and industry alike. One of the approximately 30 affected growers had 250 acres that were initially embargoed and three elevators had restrictions to prevent grain movement. Fortunately, after testing the grain for residues and not finding any, the restrictions to the elevators were lifted. One tested wheat field was extremely close to having illegal residues with 0.099 ppm azoxystrobin in the grain while the legal limit is 0.100 ppm. Imagine the cost of not being able to sell $8 wheat if illegal residues were found!

I believe the loss of public confidence in the safety of foods could be one of the biggest dangers concerning the misuse of pesticides. In agriculture, many growers rely on pesticides as an important part of their pest management programs. We have a rigorous system in place in the US regulated by the EPA through the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) to test for potential health and environmental effects. Based on this scientific information, labels are written with allowed uses and specific restrictions to ensure that potential risks are minimal. What happens if growers or applicators believe they can start using pesticides in ways that have not been tested? Will the public lose faith in our claims that we are using pesticides safely in producing their food? I hope that we do not find out what the answers are to these questions. As it has often been stated, "Read and follow the label. The label is the law."

Rich Zollinger
Extension Weeds Specialist

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