BOISE, Idaho—Treasure Valley farmers say their crops suffered some heat stress during a brutal nine-day heat wave but for the most part made it through OK.
But researchers and growers are concerned the prolonged stretch of hot days will lead to higher insect and disease pressure.
“The more heat units you have, you have more generations of insects and diseases,” said Saad Hafez, professor of nematology at the University of Idaho’s Parma research station. “We expect (we’re) going to see a lot of diseases and insects.”
Stuart Reitz, an Oregon State University cropping systems extension agent in Ontario, Ore., said there is significant concern about spider mites, which proliferate in hot, dry conditions and affect several crops grown in the region.
The high temperatures in Boise and in Ontario topped 100 degrees for nine straight days through July 4 and several records were set during that stretch.
The nine-day streak of 100-degree temps was a record in Boise, matching the previous record set in 2006 and 2003.
On July 5, the high temperature in Ontario only reached 95 and the forecast for the region has highs mostly in the low to mid-90s for the rest of the week.
“We’ve had a lot of heat for a long time,” said Nyssa, Ore., farmer Paul Skeen. “The heat’s tough on everything, including the people out working in it. This cool-down, if you can call it that, will help quite a bit.”
The tips of some onions in the valley are burned on the end of the leaves, which is a sign of heat stress, said Reitz.
But other than that, “the crops (in the valley) made it through better than I anticipated,” Skeen said.
The entire year has been unusually hot.
It was the hottest June ever in Boise, according to the National Weather Service.
According to Clint Shock, director of OSU’s Malheur County experiment station, the growing degree day index—an accumulation of heat used to predict when crops will bloom and mature—is at a record level.
There were 1,718 growing degree days from Jan. 1-July 5, far more than the typical 1,300 or fewer that could be expected by now during an average year, Shock said.
Farmers said the unusually warm year has resulted in crops at a growth stage far ahead of normal.
Skeen began harvesting wheat on June 30.
“That’s absolutely unheard of around here,” he said.
Middleton, Idaho, farmer Sid Freeman said he was detasseling corn on July 4 for the first time ever.
“Some farmers have corn that is 8, 9 or 10 feet high. Unbelievable,” he said. “The biggest thing we’re seeing from the heat right now is that the growth stage for crops is way ahead of where we normally are. Corn, sugarbeets, everything is ahead of normal. There’s never been anything like this year.”
Source: www.capitalpress.com