ISHS Acta Horticulturae 470: II International Symposium on Pistachios and Almonds
MODELING THE VEGETATIVE AND REPRODUCTIVE GROWTH OF ALMONDS |
| Authors: | G. Esparza, T.M. DeJong, Y.L. Grossman |
| Keywords: | Almond simulation model, carbon budget, carbon assimilation, carbon demand, organ growth potential, carbon partitioning |
| Abstract:
A carbon budget computer simulation model for almonds has been developed by modifying the existing PEACH model (DeJong et al., 1996. Acta Horticulturae, 416). The model simulates, on a daily basis, the seasonal carbon supply and demand for reproductive and vegetative growth. The concept behind the model is that the tree grows as a collection of semiautonomous interacting organs competing for carbohydrates, whose partitioning is dependent on organ growth potentials. Although peaches and almonds are closely related, they have some architectural and physiological differences due both to genetic differences and differing management practices (e.g. pruning and training systems, thinning, etc.). These differences required modification of some equations used in the model, however the main structure of the PEACH model was not changed. Carbon assimilation (supply) was simulated as a function of solar radiation, air temperature, accumulated degree-days, tree light interception, and leaf photosynthetic rates. Respiration and growth were simulated to determine the various organ carbon demands. Carbon partitioning was simulated based on sink strength (organ growth potential), source-sink proximity, and carbohydrate availability. The model provided a framework for integrating the environmental and physiological factors controlling carbohydrate supply and growth. Output could be scaled to the orchard level and indicated potential avenues of research related to growth and productivity. Results of the first model simulations are presented. | |
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