Start with cover crops

At the very least, Berkowitz says all grape growers can sow a no-till cover crop in the highly trafficked "avenues" surrounding their vineyards. "If those areas are seeded and mowed, that helps keep down dust, which helps keep down mites."

He also advises his clients to plant either annual or perennial cover crops in their vineyard rows — preferably between mid-September and mid-October. For vineyards whose soil is shallow or whose vines aren't strong, he recommends an annual mix of 'Zorro' fescue, 'Blando' brome and clovers. For those on flatter ground and with stronger vines, he prefers blends of such native perennial grasses as California brome, meadow barley and blue wildrye.

By curbing the vines' excessive vigor, these cover crops boost the grapes' appeal to wine drinkers and diminish their palatability to western grape leafhoppers. Berkowitz suspects that cover crops — especially "insectary" blends of flowering plants — also intensify populations of spiders, lacewings and other natural enemies of leafhoppers, thrips and mites.

During decades of advising grape growers, Berkowitz has learned that some pest management methods favor flavor while others put it at risk.

"It's kind of a subtle effect, but I think that over time the advantage increases," says Berkowitz. "You get that natural balance happening and it seems like your pest problems decrease."

Densely forested creeks surround many North Coast vineyards. "We're not cultivating fenceline to fenceline; we're striving to avoid monoculture," Berkowitz says. There's "reason to believe" this additional biodiversity contributes to pest control, he says, but more research would help.

0 -1

Post a comment