LAWTON, Mich. — Recent frosts after unusually warm weather this season have devastated the state’s grape crop in southwestern Michigan.

Richard Erdle, a spokesman for the National Grape Cooperative (NGC), which owns Welch’s, said the primary buds on grapevines have mostly been destroyed by frost. “Not all the primaries froze in Michigan,” he said. “There will be significant loss. It could be as much as 90 percent.”

The summer-like weather in March caused grapevine buds to bloom as much as five weeks early. When the frost hit, it killed most of the buds. According to the Michigan office of the USDA National Agricultural Statistics Service, temperatures in the 20s on April 12 caused more frost damage.

“On most juice grape farms in the southwest, all primary buds are dead,” the report states. “Most growers will probably not have enough grapes to make harvesting economically feasible. Wine grape damage varied by variety and age of vines.”

The most heavily affected counties are Berrien, Cass and Van Buren. Erdle said these areas should be eligible for some type of federal disaster assistance. The threshold for such assistance is a 30 percent crop loss. Republican U.S. Rep. Fred Upton’s Congressional district includes many grape farmers.

“Congress does not have an official role in crop loss disaster declarations, but Fred fully supports a disaster declaration for grapes and any other crops that have been affected by this year’s severe weather events,” said Meghan Kolassa, Upton’s press secretary. “Our office has reached out to Gov. (Rick) Snyder.”

For a county to receive an emergency disaster designation, Snyder must submit a request to USDA Secretary Tom Vilsack for approval. The USDA ultimately grants the request on a county-by-county basis depending on whether they’ve met the threshold. Eligible farmers could receive low-interest loans through the USDA. So far, the governor’s office hasn’t said anything about the crop loss.

Erdle explained it’s too early to tell what will happen ultimately with the grape crop this season, because the plant can produce secondary buds if the primary buds have been destroyed.

“Secondary buds can sometimes produce as much as 35 percent of the grapes normally produced by primary buds,” he said. “They won’t know for sure until later in the season.”

Secondary buds bloom sometime in May. Erdle said grapevines can produce tertiary buds, if secondary buds are destroyed by frost, but those don’t produce any grapes. He added there’ve been several bad frosts in the last 10-15 years.

“In general, most of the acreage is still harvested,” he said. “This is the worst frost we’ve had in southwest Michigan since 1977, because of the warm weather.”

The NGC has a fruit processing plant in Lawton, Mich., and oversees farms in New York, Pennsylvania and Ohio as well as Michigan. It also oversees farms in Washington state.

Regarding the apple crop, there have been reports of damage to some orchards.

“I think it’s too early to tell,” said Diane Smith, interim executive director of the Michigan Apple Committee. “We have the potential for a good crop yet. We have had damage in some spots. The temperature got down low enough to be of concern to growers.”

Smith said growers are taking precautions to protect their trees, such as using wind machines, which can elevate the air temperature. Others are spraying their blossoms with water to freeze them. Still others are using heaters.

She said she even heard of at least one grower that hired a helicopter service to hover over an orchard to help circulate the air around the trees.

Most of the orchards in Michigan are north of where the grape crop is raised and conditions there apparently have been better than in the state’s southwestern corner. “We’re optimistic we’re going to be okay,” Smith said.