Peach: a user friendly peach tree growth and yield simulation model for research and education

摘要

PEACH, a computer simulation model of annual carbon supply and demand for reproductive and vegetative growth of peach trees is presented. The model simulates daily and seasonal photosynthetic carbon assimilation using seasonal canopy light interception, daily minimum and maximum temperatures and solar radiation as inputs. Carbon partitioning and organ growth are simulated using daily environmental parameters with organ-specific growth and respiration potentials to determine conditional growth capacities and maintenance respiration requirements (i.e. daily carbon demand) of each organ type. Whole tree maintenance respiration is subtracted from the pool of carbon available from photosynthesis. The carbon demand for growth and growth respiration of above-ground organs is then calculated and adjusted in accordance with available carbon. Residual carbon after whole tree maintenance respiration and above-ground growth is partitioned to the roots. The model operates in the Microsoft R WindowsTM environment, allowing easy adjustment of input parameters, rate variables and state variables for conducting simulation experiments. Default variables for specific peach cultivars and orchard systems in central California are included so that theoretical simulations can be conducted without requiring a full set of site-specific data for each simulation experiment. Results from sample simulations experiments testing the effects of time of fruit thinning, location and leaf photosynthetic rate on tree growth and fruit yield are discussed.