| Following the declaration of the endemic status of Huanglongbing (HLB) in Florida in 2005 with no formal control policy for the disease, it is natural that an empirical examination and justification of the management protocols implemented at the farm-level to control HLB be made. We develop farm level decision rules to judge when it is economically justified to implement a particular control strategy. Models are developed that allow economic assessment of each strategy and determine the scenarios for which each strategy is optimal or yield a positive net present value, considering average grove age at first detection, and rates of infection at first detection. Our results justify the heterogeneous decisions of growers regarding their choice among control strategies, in a way that optimizes each grower's utility. As hypothesized, the superiority of either strategy depends upon the level of infection at the time when the disease is first found in a particular block, the rate of spread of the disease, the average age of the grove at first infection, expectations of future fruit prices, and the latency period. Our research identifies important efficacy targets that must be achieved for the long-term economic viability of a citrus grove. Our results provide a recommendation of the optimal control strategy for a given set of conditions such as the age of the planting and initial rate of infection. |
