University of California

Leafroll disease is spreading rapidly in a Napa Valley vineyard


Deborah A. Golino
Ed Weber
Susan Sim
Adib Rowhani

Authors Affiliations

D. Golino is Cooperative Extension Plant Pathology Specialist, Department of Plant Pathology, UC Davis; E. Weber was County Director and Farm Advisor, UC Cooperative Extension Napa County (deceased; see box); S. Sim is Staff Research Associate, Department of Plant Pathology, UC Davis; A. Rowhani is Plant Pathology, Specialist, Department of Plant Pathology, UC Davis.

Publication Information

Hilgardia 62(4):156-160. DOI:10.3733/ca.v062n04p156. October 2008.

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In the 1930s and 1940s, little was known about viruses, and information on plant diseases caused by viruses was just beginning to appear in the scientific literature. Problems with grapevines in California, first referred to as “red leaf,” were initially attributed to inexperience in viticultural techniques and poor growing conditions. However, the problem was later identified as leafroll disease, which causes red leaves, and poor yields and fruit quality. We evaluated its rate of spread for 5 years in a Napa Valley vineyard, and found an average rate of more than 10% per year. Leafroll disease can be vectored by low-level populations of grape mealybugs, and is now spreading rapidly in at least one Napa Valley vineyard for unknown reasons. Using stock for planting vines that is certified as virus-free is a key strategy in preventing the spread of grapevine leafroll disease.


Alley L, Golino D. The origins of the grape program at Foundation plant Materials Service. Proc 50th Annual ASEV Meeting. Seattle, WA. Am J Enol Vitic. 2000. 51:222-30.

Daane K, Bentley W, Walton V, et al. New controls investigated for vine mealybug. Cal Ag. 2006. 60:31-8.

Goheen AC. Virus diseases and grapevine selection. Am J Enol Vitic. 1989. 40:67-72.

Golino D. Potential interactions between rootstocks and grapevine latent viruses. Am J Enol Vitic. 1993. 44:148-52.

Golino DA, Sim ST, Gill R, Rowhani A. Grapevine leafroll disease can be spread by California mealybugs. Cal Ag. 2002. 56(6):196-201.

Golino DA, Sim ST, Rowhani A. The role of rootstock genotype in the effects of single and mixed infections of grapevine viruses. 2003. Bari, Italy.: Proc 14th Int Council for the Study of Virus and Virus-like Diseases of Grapevine (ICVG) Conference. p 246–7

Harmon FN, Snyder E. Investigations on the occurrence, transmission, spread, and effect of “white” fruit color in the Emperor grape. Proc Am Soc Hort Sci. 1946. 47:190-4.

Martelli GP. Major graft-transmissible diseases of grapevines: Nature, diagnosis, and sanitation. Proc 50th Ann ASEV Meeting. Seattle, WA. Am J Enol Vitic. 2000. 51:231-6.

Olmo HP. A proposed program for the introduction, improvement, and certification of healthy grape varieties. Wines Vines. 1951. 32(7):7-9.

Olmo HP, Rizzi AD. Selection for fruit color in the Emperor grape. Proc Am Soc Hort Sci. 1943. 42:395-400.

Rowhani A, Golino D. ELISA test reveals new information about leafroll disease. Cal Ag. 1995. 49(1):26-9.

Weber E, Golino DA, Rowhani A. Laboratory testing for grapevine virus diseases. Practical Winery Vineyard. 2002. 22((2)):13-26.

Golino D, Weber E, Sim S, Rowhani A. 2008. Leafroll disease is spreading rapidly in a Napa Valley vineyard. Hilgardia 62(4):156-160. DOI:10.3733/ca.v062n04p156
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