INTEGRATING PHYSIOLOGICAL MODELS IN APPLIED FRUIT CROP RESEARCH

Over decades of research on key problems of fruit production and quality, the straightforward questions have been adequately solved with straightforward field trials. However, the remaining problems are typically more complex with many factors interacting. This often gives variable and sometimes apparently contradictory results in trials with the same treatments (chemical thinning of apples for example). The underlying physiological principles are consistent, but the outcomes may differ due to the unique interactions of key factors. Models of physiological principles can help integrate many factors not easily accounted for by normal trials. Models have been developed and found to be useful in our program. Carbon balance simulation models of apple (“MaluSim”) and grape (“VitiSim”) have been used to understand cropping and pruning effects, short-term weather and long-term climate effects, and apple responses to chemical thinning. An apple-specific ET model has provided improved estimates of apple tree water use in a humid climate. A model integrating factors affecting water use efficiency (WUE) is being developed to better understand potential avenues to improve crop WUE. Extension of the models via web interfaces is expanding the use of such models for advisors and growers.