TY - JOUR T1 - Reducing the Economic Impact of Grapevine Leafroll Disease in California: Identifying Optimal Disease Management Strategies JF - American Journal of Enology and Viticulture JO - Am. J. Enol. Vitic. DO - 10.5344/ajev.2014.14106 SP - ajev.2014.14106 AU - Katie D. Ricketts AU - Miguel I. Gomez AU - Shady S. Atallah AU - Marc F. Fuchs AU - Timothy E. Martinson AU - Mark C. Battany AU - Larry J. Bettiga AU - Monica L. Cooper AU - Paul S. Verdegaal AU - Rhonda J. Smith Y1 - 2015/01/30 UR - http://www.ajevonline.org/content/early/2015/01/28/ajev.2014.14106.abstract N2 - Grapevine leafroll disease (GLRD) is a devastating viral disease found across all grape-growing regions. Vineyard managers adopt varied strategies for managing GLRD including roguing individual, symptomatic vines and replacing them with certified vines derived from clean, virus-tested stocks, applying insecticides targeting mealybug vector populations in order to reduce disease spread and minimize long-term impacts, fully replanting vineyards at the onset of disease symptom development and finally, some elect to not control GLRD at all. We collected survey data from vineyard managers throughout the major California grape-growing areas to estimate the economic impact of GLRD on Cabernet Sauvignon and identify cost-minimizing management strategies under various disease incidence levels, price penalties, timing of disease onset relative to vineyard age, yield losses and control costs. Our results estimated the economic cost of GLRD to range from $29,902 to $226,405 per hectare. Roguing symptomatic vines and replanting with certified vines in combination with applying insecticides to reduce mealybugs can minimize losses if GLRD prevalence is low (between 5–10%), while a full vineyard replacement should be pursued if disease prevalence is higher, generally beyond 25%, although regional differences were noted. These findings should help vineyard managers in the county areas of Napa, Sonoma, and Northern San Joaquin Valley adopt optimal GLRD management strategies that can be tailored regionally or locally to unique market opportunities, potential market prices and annual operating costs. ER -