Potato growers in Maine apply soil fumigation in a trial of McCain Foods

French Fry manufacturer McCain Foods has started trials examining soil fumigation with several of its potato growers in Maine (United States) and New Brunswick (Canada).

More common in western states, fumigating soil to fight nematodes and soil-borne diseases is “not something we’ve done in Maine,” Erica Fitzpatrick-Peabody, an agronomist with McCain Foods, said during the Maine Potato Conference in Caribou in January.

In an effort to boost yields with its contract growers of russet processing potatoes, McCain Foods has been conducting trials of fumigation on a small number of acres with farmers who have had yield problems with nematodes, verticillium wilt and other fungal soil pests. The Florenceville, New Brunswick-based company, which operates a factory in Easton, has been conducting similar trials with its growers in Canada.

The range of fungicides and insecticides farmers already apply to potatoes throughout the growing season “aren’t providing adequate control for soil-borne diseases,” Fitzpatrick-Peabody said.

In the fall of 2015, the company started a trial with three growers in Limestone, Presque Isle and Washburn across more than 60 acres, fumigating sections of the soil with chloropicrin, a broad-spectrum soil pesticide the growers injected into 12-inch bands of raised rows in the fall before planting potatoes.

Fitzpatrick-Peabody said the fumigated sections of the fields showed fairly significant yield increases, with an additional 90 to 106 hundredweight increase to the yield based on the varying amounts of the chemical the grower applied. The average yield per acre for Maine potatoes in 2015 was 315 hundredweight, according to the U.S. Department of Agriculture.

Fitzpatrick-Peabody said the trial also showed yield increases just from preparing raised rows the fall before planting, without fumigation, with those sections of fields seeing an average increase of 35 hundredweight.

Erica Fitzpatrick-Peabody:
 

“It’s one year of data. We have more detailed work for 2017, and we’ll have a lot more to talk about next year.”

Last fall, farmers fumigated 13 fields of McCain growers from Houlton to Saint Agatha with chloropicrin, and the company will share those results from those fields next year, she said.

Maine potato growers have not used fumigation in the past, in part because of northern Maine’s cold winters keeping soil-borne pathogens in check, according to the Maine Potato Board’s 2013 Industry Report. While potatoes receive sprays of fungicides, insecticides and herbicides to kill the plant vines in the weeks prior to harvest, Maine potato growers use a tenth of the total amount of active pesticides growers use in other major potato regions, according to the report.