Stollberg manages Presqu’ile’s vineyards and viticulture program through his farm management and consulting business, Maverick Farming.

Looking at grape production practices, Stollberg’s yield targets for Presqu’ile-grown fruit is 3 tons per acre for Pinot Noir, 4 tons/acre for Chardonnay, 4.5 tons/acre for Sauvignon Blanc, 3.5 tons/acre for Syrah, and 2 tons/acre for Nebbiolo.

Twenty-two clones are grown.

“Our basic philosophy is to use minimal inputs to reach the target quality characteristics and tonnages,” Stollberg said.

The target brix level for Chardonnay is 21.5-22, Pinot Noir 22-22.5, Syrah 22.5-23.5, and Sauvignon Blanc 21-22.

Vineyard spacings are close - 4X6 and 4X8. All vines are trellised with the vertical shoot position (VSP) system.

“The vineyards are planted in close spacings to produce the needed grape tonnage and quality to make the operation economical,” Stollberg said. “We can’t carry too much fruit on the vines due to the sandy, low-vigor soils.”

Most rootstocks on the ranch are 3309, 101-14, and 1103P.

“We have diverse rootstocks based on changes in soil structure and soil depth which impact drought susceptibility,” Stollberg explained. “Some vines are planted on their own rootstock, including some Chardonnay and Pinot Noir.”

Grapes are grown under certified “Sustainability in Practice” guidelines.

On the plant disease and pest front, powdery mildew is common in the SMV due to the long, cool growing season. Stollberg applies spray applications of the fungicides Quintec, Flint, Mettle, Abound, and Kocide in rotation to provide mildew and botrytis control.

The mantra on shoot and cluster thinning is to maximize vine uniformity down the row and manage pests. Work crews cluster thin, pull leaves, remove suckers, and harvest by hand.

All irrigation is with groundwater. Since the vines grow in shallow, sandy soils, the irrigation cycles are frequent and for shorter periods of time – usually 2-3 times a week early in the season. Once veraison occurs, irrigations are spread out to every 3-4 days and then 4-5 days to move the vine from vegetative growth to fruit maturation.

About two acre feet of irrigated water is applied annually. Until recent years, the Santa Maria Valley received about a foot of rainfall annually. The last couple of years have been rain short. Groundwater levels are beginning to drop.

“We all need a long, wet winter where the water doesn’t all run out to the ocean,” the vineyard manager said.

Water needs in the vines are determined by visual cues of the vine and leaves - the condition of shoot tips, petiole blade leaf angles, and the inner node length.