San Rafael, Calif.—A just-published new guide to organic grapegrowing, written by experts in the field, is one of the most comprehensive texts about viticulture written in the past 30 years, providing valuable data that will be useful even to conventional growers.

Authored by a panel of University of California researchers and others, “Organic Winegrowing Manual” presents detailed, step-by-step analyses of all phases of organic grapegrowing, from soils to canopy management and pest and disease control.

Wines & Vines columnist Glenn McGourty, UC cooperative extension winegrowing and plant science advisor for Lake and Mendocino counties, edited the book and wrote some chapters. He said that while the book comes from a “California-centric” perspective, it offers a complete look at establishing and tending a vineyard. Compiled by McGourty as well as Dave Chaney and Jeri Ohmart, publication coordinators at the UC Sustainable Agriculture Research and Education Program (UC SAREP), the book represents the work of 15 author/researchers. McGourty served as technical editor and said it's the most comprehensive work since "General Viticulture" by A.J. Winkler (reissued in 1974).

“It’s a user manual for someone who wants to farm organically,” McGourty said. “They could find pretty much everything they needed to know in that book.” Following the steps in the book would provide winery owners with a road map toward earning third-party organic certification and putting “organic” on their wine label, he said.

Growers who are already farming quality grapes with sustainability in mind won’t find the next step to organic that high a hurdle. “It’s not super different from quality winegrowing that most growers already use. Organic growers are limited in their chemical tool bin,” according to McGourty.

Ready for a change?
For growers in areas where organic methods are not so prevalent, McGourty acknowledges that making the switch could be more challenging because of “more pesticide use, which has the potential to limit beneficial predacious insects.”

McGourty wrote the chapter about cover crop systems for organic vineyards: It summarizes how organic growers mix different cover crops to protect their soil and how those plants can interact with grapevines.

The full-color guide features 18 tables and 89 figures, and photos depicting notable pests as well as what McGourty described as “beauty shots” of Mendocino County vineyards by Ukiah, Calif.-based photographer Tom Liden. There are nearly 4,000 acres of certified organic vineyards in Mendocino County—more than anywhere else in California—according to state crop reports.

McGourty said he was honored to work with Dr. Pete Christensen on one of his last UC publications. Christensen, who died in 2011, contributed an overview of organic fertilizers, and information about soil nutrients and their uptake by vines.

Drs. Doug Gubler and Jenny Broome provided a summary of vine diseases in California that Mc Gourty termed “a valuable reference for anyone interested in grapevine diseases.”

Seven experts, including McGourty, co-wrote the chapter “Biodiversity, Habitat and Natural Resource Issues in Winegrape Production.” McGourty said the group strove to define biodiversity and explain in detail the factors affecting it.

A truly collaborative effort, the book took more than seven years to complete. In 2004, Dr. Sean Swezey, then director of the UC SAREP, initiated the project after receiving grant funds to publish a series of organic growing manuals.

The paperback guide sells for $35 through the University of California Agriculture and Natural Resources Press; order online from anrcatalog.ucdavis.edu.