WOODBURN, Ore. (AP) — Farmers and vineyard owners in Oregon are worrying that the extensive heat wave in the state may be doing damage to their crops.

The Capital Press reported Monday (http://bit.ly/2vd3SV4 ) that excessive heat can blister or sunburn wine grapes, which are still developing and won't be harvested until September. Late season raspberries may develop white dots due to sun scald and blueberries may not reach their ideal size because of a lack of water.

"The plant can't pump enough water, so it shuts down and interferes with sizing," crop consultant Tom Peerbolt said of the blueberries. "Fortunately a lot of the commercial folks have installed cooling systems, and they pay for themselves in an event like this."

With temperatures topping 100 in Portland and throughout Western Oregon the first three days of August, some growers ran the misters eight hours a day, Peerbolt said. He said the systems are a large infrastructure expense, but are intended to handle situations of extreme heat.

Climatologist Greg Jones, incoming director of Linfield College's wine education program, said the current heat wave is unusual for its magnitude and length, and may turn out to be Oregon's most extreme since 1981.

Vineyards could see sunburn on the fruit and dried out leaves, he said.


Information from: Capital Press, http://www.capitalpress.com/washington