What is in this article?:
- California vineyards will likely need irrigation much earlier than normal.
- It’s a good time to assure that water will be delivered to wine grape crops as temperatures warm.
- Adding too much nitrogen can spur vegetative growth that means even more demands for water.
The lack of rain that has punctuated California’s fall and winter could have sapped some of the reserve for the state’s wine grapes and could lead to uneven bud break and other challenges.
And it’s a good time — well before those grapes start to form — to take a look at how to assure that water will be delivered to the crop as temperatures warm.
That was among advice given to those who attended a grape grower tailgate meeting in the Parlier area presented by the San Joaquin Valley Winegrowers Association and California Sustainable Winegrowing Alliance.
The Running Luck Ranch meeting was one of three sessions at which topics included tractor safety, sustainable growing practices, crop insurance, irrigation management for a dry season and pest and disease management. The other meetings were held in Bakersfield and Ceres.
“I guess we can’t hear too much about water this year,” said Bill Chandler, a Fresno County grower, after the program ended.
Indeed, participants in the tailgate session got their fill — not their fill of water perhaps, but of talk about it.
In his discussion of pest and disease management, consultant Ron Brase warned that the dry fall and winter could mean decreased carbohydrate accumulations in vines, which could be problematic.
“It could mean increased susceptibility to freezing, though that has not been a problem this year,” he said. “And it could mean erratic bud break, reduced spring vigor and an early season boron deficiency.”
Moreover, the erratic growth in vines “could raise havoc with phomopsis,” Braise said. And he suggested use of a boron foliar might be in order.
Brase, president of AgQuest Consulting Inc. in Fresno, said it’s important growers assess the moisture levels in their vineyards with instruments that could include hand probes and augers.
“Vineyards will likely need irrigations much earlier than normal,” he said.
As with several other speakers, Brase recommended growers use Internet searches to find a wealth of information, including assessment of powdery mildew risk.
His pointers included:
• Don’t wait to take preventive steps for phomopsis or leaf spot. “If rain is forecast, treat,” he said, pointing out that rain can spread the fungus.
• Combating powdery mildew, which has been a major problem the past three years, means assessing risk and having a treatment plan. Once it has evolved to a full-blown infection, it may be impossible to clear out of grape clusters.
• Vine mealybug can be controlled with chemicals that include Movento and Admire. Movento has the added quality of suppressing nematodes.
• Some treatments can be lumped together. For example, treatment for omnivorous leaf roller and vine mealybug and application of foliar zinc spray can be done with powdery mildew treatment.