Shady S. Atallah

Economic Impact of Grapevine Leafroll Disease on Vitis vinifera cv. Cabernet franc in Finger Lakes Vineyards of New York

Leafroll disease is one of the most important virus diseases of grapevines worldwide. It reduces yields, delays fruit ripening, reduces soluble solids, and increases titratable acidity in fruit juice. This study uses a net present value (NPV) approach over a 25-year lifespan of a vineyard to examine the economic impact of grapevine leafroll disease (GLRD) on Vitis vinifera cv. Cabernet franc in Finger Lakes vineyards of New York. It identifies optimal disease control options under several scenarios of disease prevalence, yield reduction, and fruit quality effects. The estimated economic impact of GLRD ranges from approximately

Reducing the Economic Impact of Grapevine Leafroll Disease in California: Identifying Optimal Disease Management Strategies

25,000 (for a 30% yield reduction and no grape quality penalty) to

A Plant-Level, Spatial, Bioeconomic Model of Plant Disease Diffusion and Control: Grapevine Leafroll Disease

40,000 (for a 50% yield reduction and a 10% penalty for poor fruit quality) per hectare in the absence of any control measure. The per hectare impact of GLRD can be substantially reduced to

Specification of Spatial-Dynamic Externalities and Implications for Strategic Behavior in Disease Control

3,000–

Addressing agricultural nitrogen losses in a changing climate

23,000 through roguing if levels of disease prevalence are moderate (1–25%). With disease prevalence levels greater than 25%, replacing the entire vineyard is the optimal response, yielding economic losses of ~

Localization effects for a fresh vegetable product supply chain: Broccoli in the eastern United States

25,000/ha. Furthermore, the use of vines derived from certified, virus-tested stocks in replant sites is predicted to keep the costs associated with GLRD infection to ~

Spatially explicit return on investment to private forest conservation for water purification in Indiana, USA

1,800/ha. No intervention appears to be economically optimal when (1) infection levels are high (>25%), yield reduction is moderate (<30%), and no price penalty is enforced or (2) when GLRD is transmitted through vectors after year 19. These findings are valuable to construct integrated decision matrices for vineyard managers to devise profit-maximizing disease control strategies and to create incentives for extended uses of clean, virus-tested planting material.

An Agent-Based Model of Plant Disease Diffusion and Control: Grapevine Leafroll Disease

Grapevine leafroll disease (GLRD) is a devastating viral disease found across all grapegrowing regions. Vineyard managers have adopted various 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 to reduce disease spread and minimize long-term impacts; and fully replanting vineyards at the onset of disease symptoms. Moreover, some managers elect not to control GLRD at all. We collected survey data from vineyard managers throughout the three major California grapegrowing counties, Napa, Sonoma, and Northern San Joaquin Valley, to estimate the economic impact of GLRD on Cabernet Sauvignon vines. The goal was to identify cost-minimizing management strategies under various disease-prevalence levels, price penalties, timing of disease onset relative to vineyard age, yield losses, and costs of control. Our results estimated that the economic cost of GLRD ranged from

A Bioeconomic Model of Ecosystem Services Provision: Coffee Berry Borer and Shade-grown Coffee in Colombia

29,902 to

Achieving multiple goals via voluntary efforts and motivation asymmetry

226,405 per ha. Roguing symptomatic vines and replanting with certified vines in combination with insecticides to reduce mealybugs may minimize losses if GLRD prevalence is low (between 5 and 10%), while a full vineyard replacement should be pursued if disease prevalence is higher, generally above 25%, although regional differences were noted. These findings should help vineyard managers in the three regions examined to adopt optimal GLRD management strategies that can be tailored regionally or locally to unique market opportunities, potential market prices, and annual operating costs.