Pinot gris grapes in an Easton vineyard need the heat, but too much of it over an extended period can cause sunburn in the berries. The heavier the canopy over the grape bunches the more protection but the sun has already burned some leaves.
"When we have long durations of high temperatures what it does it stifles growth, sugar accumulation. It doesn't allow the plant to do anything. It goes into maintenance mode," said farm advisor Stephen Vasquez.
Hundreds of growers and vintners gathered in Northwest Fresno for the annual Allied Grape Growers Meeting. Global demand is strong. They expect to produce a large, quality crop this year.
But the growers are also ready for a cooling off period. They've all been soaking their vines to protect them from the heat. "Higher humidities help to a certain point on keeping sunburn from happening on certain varieties there unless we get to 110 or 111 degrees that could be very detrimental," said Easton grower Ray Jacobsen.
Jacobsen says temperatures up to 107 degrees don't pose too many problems. But because of the intense heat this week, many workers have been starting much earlier -- trying to get done by noon.