PRESQUE ISLE — A crop specialist with the University of Maine Cooperative Extension is informing the state’s potato farmers that they might need to reduce use of a widely used pesticide that controls blight.

Steven Johnson said national and international changes in the regulation of a fungicide called chlorothalonil could prompt the changes, the Bangor Daily News reported. He said growers might consider moving to newer kinds of chemicals.

Chlorothalonil has been used extensively in the farming of potatoes and other crops since the 1970s. However, the U.S. Environmental Protection Agency considers it a “likely human carcinogen” and has attempted to reduce its use.

Pesticide control is especially important for Maine’s potato growers because much of the processing potato crop in Aroostook County, the center of the state’s potato business, is russet potato varieties. Those potatoes can be susceptible to late blight, a disease that rots them.

Maine is the largest potato-producing state in the eastern U.S., and is typically in the top 10 producers in the country. The crop is of high economic importance to rural parts of northern Maine.

Johnson said there are “a lot of better and newer chemistries that have better and longer efficacy” than chlorothalonil. The European Union banned the pesticide in March, and Canada has reduced the amount that can be used during the growing season. An EPA review is also expected next year.