Modeling postharvest loss and water and energy use in Florida tomato operations.

• Models on interactions of postharvest food quality, water and energy are developing. • An existing model was enhanced and implemented for a representative tomato operation in Florida. • Results were upscaled to obtain statewide estimates of water, energy and PHL. • Model estimates were 20% lower than observed values for each operation. • PHL was 22% for the case study operation and upscaled to 16% for the state of Florida. • The model indicates that operations for one box uses 0.81 L of water ad 2.0 kWh of energy. With a growing worldwide population, feeding 10 billion people by the year 2050 is the next global challenge. Fresh produce systems account for a significant fraction of total food and resource consumption due to their perishable nature, with postharvest quality being a key challenge. Production models for fresh produce are widely used and well adapted, whereas postharvest operations (PO) models have only recently been developed. The overarching goal is to quantify interactions of food quality, water and energy use in PO. In this study, an existing PO model was enhanced and implemented for a field grown tomato operation in Florida. Model estimates were compared with data from a representative operation, and were upscaled to obtain statewide estimates. The enhanced model was found to be the most sensitive to harvest frequency, quantity shipped to customer, and quantity harvested. At maximum grower profit, the model estimated water and energy quantities roughly 20% lower for each operation. The representative operation exceeded optimal water and energy usage because the farmers, despite having efficient production, commonly "over-produce" far beyond optimal levels for reasons including risk of loss, tradition, low market prices, and large fixed costs of operation. Postharvest loss estimated by the model was 22% of quantity harvested for the representative operation. The upscaled regional postharvest losses were at 16% for the state of Florida. Operation-specific water and energy use from the case study were upscaled to give regional monthly estimates of 50.3 million liters and 28.3 million kWh, respectively. Such interactions provide insights into postharvest decisions made by commercial operations and impacts of these decisions on the food, water and energy system. The integrated modeling framework in this study can be extended to other crops and quantify interactions of water, energy and, postharvest losses to optimize efficient management practices. [ABSTRACT FROM AUTHOR]