A multiple-objective linear programming model for the citrus rootstock selection problem in Florida

Citrus is one of Florida's key agricultural crops, with annual production accounting for over 70% of all US production. During the 1970s and 1980s, citrus blight, tristeza and freezes caused citrus rootstock selection to become a critical issue in Florida, and it remains so today. This paper describes a multiple-objective linear programming model that we have developed for solving the citrus rootstock selection problem in Florida. The model has four objective functions. These functions, together with the constraints of the model, capture the main factors that Florida citrus growers use in choosing portfolios of rootstocks for planting in their groves. We tested the usefulness of this model by solving an experimental application for the Fort Pierce area with the interactive STEM algorithm. From our reseach we conclude that, when properly solved with the aid of STEM, the multiple-objective linear programming model has the potential to serve Florida citrus growers as a useful decision aid in formulating rootstock selection plans.