Adequate supplies of irrigation water enabled Mitchell to minimize any water stress on his vines from two hot spells, one in early May and another around the middle of the month, when temperatures pushed up to the low 90s.

All his vineyards are irrigated with well water. Normally, by this time, this area would have received 10 to 12 inches of rain since Oct. 1. This season, rainfall during that time has totaled only about 4.5 to 5.5 inches, depending on the site, Mitchell reports.

“Groundwater levels don’t appear to have dropped much during the drought,” he says. “We’ve been able to maintain our normal irrigation rates, and we’re seeing some really good growth in the vineyards.”

In fact, now Mitchell and his crews are starting to put the brakes on some of that growth using deficit irrigation and canopy management to direct more plant energy from the foliage into the fruit to enhance grape quality.

By the end of May they had begun removing leaves on the morning side of the vines to expose the fruit to more sunshine, while retaining enough leaves to protect the berries from sunburn.

Leaves in blocks where grapes are destined for higher quality wines are pulled by hand. On others, where higher grape yields are the goal, leaves are removed mechanically.

Once leafing is completed, a critical pass through the vineyard will be made with fungicides for controlling powdery mildew and botrytis before the clusters get too tight.

Usually, this is done in late June. This year, however, Mitchell expects to make his closure sprays in the second week of the month.

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