New research supports old-fashioned pest management.
If the California vineyards are looking more vibrant than usual, it might be due to blossoming new research by Berkeley agroecologists. For more than three years, they’ve been working with grape growers in Napa, San Joaquin, and Fresno counties to plant flowers that attract pest-eating insects, as part of research that will ultimately pit the effectiveness of such techniques against chemical pesticides. Pioneering the work are Berkeley agroecolologist Miguel Altieri, entomologist Kent Daane, and graduate students Albie Miles and Houston Wilson.
Agroecology in its ideal form is the harmonious blending of modern farming practices with traditional ones. It strives to preserve a “coevolution between culture and nature,” says Altieri, who recently returned from working with rice paddy farmers in China to assess symbiotic systems of koi ponds and rice plants. If his team is successful, their work will prove that a vineyard full of buzzing and blossoming flora and fauna can outproduce a monocrop culture.
This past year, Miles gathered data on a common grape pest—the Western grape leafhopper—over a 22-acre stretch of land on Vino Farms just south of Sacramento. Between rows of white wine grapes, his team planted lavender-and-white swaths of wild carrot flowers, bishop’s weed, and lacy phacelia. They collected predators, notably a tiny parasitic wasp, using sticky traps, insect nets, and by peering at the undersides of leaves. The team’s challenge now is to establish that interspersing the grapes with flowers increases the abundance and longevity of predatory insects that eat pests. Results are due out this fall.
Companion planting is nothing new, but it takes time to cultivate understanding of the necessary agricultural system. “It’s easier to just say, I don’t want to deal with understanding nature; just spray the hell out of it,” says Altieri. But flowers can play many roles, including attracting pollinators, preventing erosion, and reinvigorating the soil. The method is also adaptable: If the vineyard is close to a forest, home to many predators, researchers can create a “corridor” of flowers to lure the insects into the vineyard—a technique Wilson is investigating. Plus, for farms like the Benziger Family Winery in Sonoma, which took part in the study, the extra splash of color has drawn ecotourists. The winery, which is ringed with flowers, attracts 10,000 visitors a year.
If it works, planting flowers could benefit the wine-growing regions of Spain, France, and Italy, according to Altieri. But could this technique really feed the world? “Absolutely,” the agroecologist says. “I work with farms in Chile that are blueberry plantations that are 1,000 hectares—that’s 2,000 acres. It can be done.”