A little money up front for disease-free grapevines and rootstock more than pays for itself in the long run, according to an economic study conducted by the University of California, Davis.

The researchers, led by postdoctoral scholar Kate Binzen Fuller in the agricultural economics department, found screening for one single pathogen saved more than $60 million annually for the Napa and Sonoma county winegrape growing region.

"The overall benefits of such testing and certification are, in fact, dramatically higher," she said in a news release.

The group examined grapevine leafroll-3, the dominate grapevine virus in California and internationally.

They found that the monetary benefits of initial screening and cleaning up of diseased vines far outweighed the costs related to screening and vine replacement.

"Even if growers have to pay a premium for certified, virus-free vines, this study suggests that they will receive a very large benefit. For the scenarios we evaluated, benefits are between six and 10 times the cost," she said in the release.

Grapevine leafroll-3 is one of many strains of the viral grapevine disease, which causes leaves to redden and roll under around the edges. It also decreased fruit production and quality, slows fruit maturation and reduces fruit pigmentation.

Growers have reported yield reductions of more than 30 percent in extreme cases.

To prevent such diseases from being introduced or spreading, several clean-plant centers around the national have been established.

In California, the Foundation Plant Services at UC Davis acts as a clearinghouse for plants that have been certified as virus-free.

Using just grapevine leafroll-3, the researchers estimate that the certification program yields a benefit of between 30 and 47 cents per vine, or between $401 and $616 per acre. If every grower along the North Coast were to use certificated planting stock, the benefit would be $40.4 million to $61.8 million per year.