Stanislaus County wine grape grower Ken Yonan, Ceres, Calif., likes what he is seeing so far.
His vines are developing pretty much on schedule. The bunches on his 20 acres of Chardonnay, which began blooming May 8, are about six inches long, and Merlot bunches are averaging about an inch longer. Bloom on those 35 acres of vines started May 12.
He is encouraged by his bunch count — about 7 percent more than normal and about 10-percent more than last year’s weather-challenged crop. Shoot growth uniformity is good.
“The uniformity in the Merlot was surprisingly good,” says Yonan, a director of Central California Winegrowers. “Usually, there’s some variation. This uniformity indicates more even color development and ripening of the grapes; as a result, it should be a good year.”
His fields escaped the early April frost that damaged other vineyards in his area. The temperature slipped to just below 31 degrees. He credits the moist soil from his drip system — which he turned on two days in advance of the predicted arrival of the cold front — with protecting his vines. Four years ago, his vineyards suffered heavy damage from freezing spring temperatures.
Earlier this year, he treated with lime sulfur right after pruning to control Eutypa dieback, which delays shoot emergence and causes shunted shoots
To control powdery mildew, Yonan alternates spraying one of three different systemic fungicides with a treatment of sulfur. He applies sulfur every seven days on his Chardonnay and every 10 days on Merlot, which is less susceptible to the disease.
Early in June, he’ll combine the systemic powdery mildew spray with both an insecticide, to prevent problems later in the season with leafrollers and aphids, and a fungicide, to control bunch rot.
Right after that, he’ll make the first of two flood irrigations of the year to supplement drip moisture.
“I don’t like to leave a gap between the soil strata wetted by the drip system and those which the flood irrigations reach,” Yonan says. “I test soil moisture at three feet, which is about as deep as the drip irrigation goes. When that starts to get dry, I flood irrigate the field.”
This year, the four acre feet allocation of surface water he normally receives has been cut in. And as supplies of surface water have gone down this season, the price of another key input, diesel, has gone up. Currently, farmers in his area are paying around $4 to $4.25 per gallon, Yonan says. Fortunately, he’s still drawing from tanks he filled last fall with red diesel that cost $2.75 per gallon.
Increased costs of inputs, like fuel, are being more than offset by improved prices he and other growers are receiving for their wine grapes this season in a tight supply market.
“I look for Chardonnay and Merlot prices to be about 20 percent to 25 percent better than last year,” Yonan says. “In fact, because wineries want more grapes, I see prices remaining strong for at least another six or seven. This is a time when farmers are starting to smile a little bit.”