To achieve high yields and top quality, Jim has learned that canopy management is paramount in Muscat production.

“A heavy canopy is essential to reduce sunburn on Muscat fruit,” said Erickson. “Muscat grapes are very sensitive to hot and cold temperatures. A long duration of high temperatures at the wrong fruit development stage can cause significant yield loss.”

To offset this summer’s hot temps, Erickson will apply the sunburn protective product Surround in late July to early August. Temps can hover in the low 100s for 30 to 40 consecutive days. Sunburn protection is only applied to the Muscats; not the other grape varieties.

Sunburn products reduce the moisture loss through the leaves and do a good job protecting Muscat fruit, Erickson said.

Growing native grass in the row centers reduces temperature and the sun’s reflectance. Sun reflecting off bare soil and irrigation water can burn the grapes.

“We keep the canopy as long as possible since Muscat fruit clusters hang 3 to 4 inches above the ground,” Erickson said.

Another important practice is to stay out of the vineyards as much as possible. Using smaller tractors to tow mowers and other equipment helps protect the canopies from damage. Mowing only occurs when the temperatures are cooler.

For two decades-plus, the family has irrigated every other row in all grape varieties.

In general, 3.5 to 4 acre-feet of water is required for grape production in the Madera area. This year, water supplied from the Madera Irrigation District will provide a 60-day supply; down from the 90-day supply in 2010, which followed a wet winter.

Most of the vineyard blocks are flood irrigated, but the farm is slowly moving to all surface drip as funds are available.

About two-thirds of the almond acreage is under drip. Micro sprinklers irrigate the olives.  

Erickson noted that his canopy management techniques work well on his farm, but may not be as applicable in other California Muscat grape-growing areas.