Profit Maximizing Control Strategies in the Grape and Wine Industry

Grapevine leafroll disease (GLRD) threatens the economic sustainability of the grape and wine industry in the United States and around the world. This viral disease reduces yield, delays fruit ripening, and affects wine quality.

Shady S. Atallah, Miguel I. Gomez,Jon M. Conrad, and Jan P. Nyrop from the University of New Hampshire published a Plant-level, Spatial, Bioeconomic Model of Plant Disease Difussion and Control: Grapevine Leafroll Disease in the American Journal of Agricultural Economics.

The project examines the impact of alternative disease control strategies on distributions of bioeconomic outcomes and ranks them based on the vineyard expected net present values (ENPVs). Using simulation modeling them to analyze alternative disease control strategies that would not be possible using classical approaches. The originality of the results lies in the computational method’s ability to model a large number of bioeconomic, plant-level state variables.

The findings show that spatial strategies targeting immediate neighbors of symptomatic vines dominate nonspatial strategies, increasing the vineyard expected net present value by 18% to 19% relative to the strategy of no disease control. The University of New Hampshire Team also find that age-structured disease control is preferred to non-age-structured control but only for nonspatial strategies. Sensitivity analyses show that disease eradication is possible if either the disease transmission rate or the virus undetectability period is substantially reduced.