Modeling subtropical tomato crop production

Crop models are a versatile tool in the integrated management of vegetable crop production. The ability to accurately forecast the time that a tomato crop will be ready for harvest and the yield of fruit from the crop is valuable both for managing the harvest scheduling and informing marketing decisions. Currently available tomato crop models have been developed for greenhouses production in temperate climate US and European production conditions, but have limited application to subtropical and tropical climate field production systems. This project has identified field factors that need to be incorporated into tomato crop models to simulate field production under subtropical conditions. Assessments of crop flowering and fruit development phenology demonstrate significant soil type and site effects. Treatment of seedling transplants, including age at transplanting, affect flowering time and yield. Significant soil type effects on flowering and harvest date have been demonstrated and may be related to variations in soil moisture availability under standard irrigation management practices. Flowering date accounts for approximately 50% of the variation in initial harvest date but other factors such as branching pattern also appear to influence timing of harvest in semi-determinant type tomatoes under field conditions. Development of a model that incorporates these variables will be a useful tool in implementing good agricultural practices in field tomato production in subtropical and tropical climates