EXETER, Maine — For 30 years, Exeter potato farmer Neil Crane used the calendar and his personal field experience to determine when to irrigate his potatoes and when to begin spraying fungicides.
“He used to look at a plant, judge its size and the time of year, and decide it was time to spray,” Steve Crane, part owner of Crane Bros. Inc., said Tuesday.
But under a partnership with the University of Maine Cooperative Extension, science now is ruling the calendar at Crane’s farms.
Using an on-farm computerized weather station that feeds data to the university and scouts from UMCE that visit individual fields, Steve Crane can tell precisely when to water or treat his uncle’s 1,300 acres of potatoes.
“Every time I spray [for late blight] it costs $15,000” Crane said. “Using the UMCE system, we can eliminate an average of four applications a year.”
Potato late blight is a fungal disease. It caused the great potato famine in Ireland in 1845, which killed 1 million Irish and caused another million to emigrate.
If not caught early, while the plant is still growing, “it can take a field down in three to four days,” said Jim Dill, UMCE pest management specialist. “If the fungus grows, rain or irrigation can wash it off the leaves and onto the tubers. When the potatoes are stored, the fungus sits there fat and happy and feeds off the potatoes. When you open the storage door in the spring, the crop oozes out.”
Dill said that more than 60 percent of the Maine fields that were examined last year by UMCE scouts were found to contain blight. “But because of our diligence, the crop that went into storage was in great shape,” Dill said.
In a potato storage facility owned by the Crane family in Exeter, the evidence was clear Tuesday: 16,000,000 of last year’s spuds — stored in just one of several bunkers — were being shipped out.
Millions of potatoes rumbled along on conveyer belts that rolled them through a washer, then on to a $250,000 sorter that kicked out defective potatoes, rocks and other field debris. The defects are diverted into cow feed while the remaining sound potatoes head to a Frito-Lay potato chip factory in Killington, Conn.
“Within six to 10 hours, all of these potatoes will be chips,” Crane said. “That plant accepts 18 tractor-trailer loads of potatoes a day.” All of Crane Bros.’ potatoes are contracted to Frito-Lay.
“This is a great partnership,” Crane said of the relationship with UMCE.
Dill estimated that Maine potato farmers were able to save an estimated $17 million worth of their 2008 crop through the early detection surveillance. Maine’s potato industry has a value of $500 million and employs about 6,000 people. It is Maine’s top agricultural commodity.
“We coordinate a statewide network of electronic weather stations and survey 100 potato fields on a weekly basis for weeds, insects and diseases,” Dill said. The data collected by the UMCE scouts help track potential pest outbreaks. It also helps farmers minimize pesticide applications and maximize yield.
Dill estimated that 95 percent of the participating farmers saved money using the system.
“We use Extension weekly or more often,” Crane said. “Their research and advice has helped us provide a better-quality product and helped us in our management practices.”
This year, UMCE and its Canadian counterparts plan to work closely with the hope of further minimizing potato late blight.