Testing a Module in CROPGRO-Tomato for Predicting Fresh Weight and Size of Individual Fruits on a Cohort Basis.

A number of tomato crop models have been developed which simulate fruit yield based in cumulative dry matter. Tomato growers, however, would be more interested in models that could predict the weekly pattern of yield on fresh weight basis including variation in marketable size. Such models could assist growers in planning their management and commercialization strategies especially relative to harvest timing and fruit quality. Tomato production varies week to week and accurate predictions are hard to achieve. The developmental stage and growth rate of individual fruits are influenced by environmental, cultural and genetic traits.  Therefore, functional relationships need to be understood in order to build useful simulations. This paper reviews the literature concerning the factors that regulate single fruit growth patterns and increases in size for fresh market tomato.  The paper analyzes the use of this information to support improving tomato crop models.  A conceptual model is presented for predicting fresh weight and size of fruits over time, starting with crop-model-predicted dry mass per fruit and fruit thermal age.