Sonoma Coast grape grower David Hirsch was seriously injured Saturday in a tractor accident at his Fort Ross-area vineyard, emergency personnel and others said Monday.

Hirsch, 70, reportedly was on foot, showing an employee how to use the tractor, when he was struck in the head with the huge bucket, causing severe skeletal and other injuries, according to county emergency dispatchers and others.

Emergency medical personnel were summoned around 2 p.m. to the ridgetop vineyard off Bohan Dillon Road, dispatchers said.

Hirsch was airlifted to Santa Rosa Memorial Hospital, where he was listed in serious condition Monday, a hospital spokeswoman said.

Hirsch is the founder and owner of Hirsch Vineyards, a producer of premium pinot noirs and chardonnays. His grapes also go into a variety of wines made by the likes of Williams Selyem, Littorai and Kistler Winery.

Family members were not available for comment on Monday, a winery employee said, and the extent of Hirsch's injuries was unclear.