BERKELEY, Calif. - Robert Mondavi, 94, the pioneering vintner who helped put California wine country on the map, died at his Napa Valley home yesterday.

Mr. Mondavi died at his home in Yountville, Robert Mondavi Winery spokeswoman Mia Malm said.

He was 52 and a winemaking veteran in 1966 when he opened the winery that would help turn the Napa Valley into a world center of the industry. Clashes with a brother that included a fistfight led him to break from the family business to carry out his ambitious plans with borrowed money.

"He had the single greatest influence in this country with respect to high quality wine and its place at the table," said wine critic Robert Parker.

When Mr. Mondavi opened his winery, California was still primarily known for cheap jug wines. But he set out to change that, championing use of cold fermentation, stainless steel tanks and French oak barrels, all commonplace in the industry today. He introduced blind tastings in Napa Valley, putting his wines up against French vintages, a bold move.

Always convinced that California wines could compete with the European greats, Mr. Mondavi engaged in the first French-American wine venture when he formed a limited partnership with the legendary French vintner Baron Philippe de Rothschild to grow and make the ultra-premium Opus One at Oakville. The venture's first vintage was in 1979.

The success of the Mondavi winery allowed him to donate tens of millions of dollars to charity, but a wine glut and intense competition gradually cost his family control of the business. In 2004, the company accepted a buyout worth $1.3 billion from Fairport, N.Y.-based Constellation Brands.

Mr. Mondavi was an enthusiastic ambassador for wine - especially California wine - and traveled the world into his 90s promoting the health, cultural and social benefits of its moderate consumption.

Born in Virginia, Minn., he earned an economics degree from Stanford University in the 1930s.