© 1994 Heron Publishing—Victoria, Canada
PEACH: A simulation model of reproductive and vegetative growth in peach trees
Yaffa L. Grossman and Theodore M. DeJong
Department of Pomology, University of California, Davis, CA 95616, USA / Received May 26, 1993
Summary
The hypothesis that carbohydrate partitioning is driven by competition among individual plant organs, based on each organ's
growth potential, was used to develop a simulation model of the carbon supply and demand for reproductive and vegetative growth
in peach trees. In the model, photosynthetic carbon assimilation is simulated using daily minimum and maximum temperature
and solar radiation as inputs. Carbohydrate is first partitioned to maintenance respiration, then to leaves, fruits, stems
and branches, then to the trunk. Root activity is supported by residual carbohydrate after aboveground growth.
Verification of the model was carried out with field data from trees that were thinned at different times. In general, the
model predictions corresponded to field data for fruit and vegetative growth. The model predicted that resource availability
limited fruit and stem growth during two periods of fruit growth, periods that had been identified in earlier experimental
studies as resource-limited growth periods. The model also predicted that there were two periods of high carbohydrate availability
for root activity. The fit between model predictions and field data supports the initial hypothesis that plants function as
collections of semiautonomous, interacting organs that compete for resources based on their growth potentials.
Keywords:
carbohydrate partitioning, carbon demand, organ growth potential, peach simulation model, photosynthetic carbon assimilation,
respiration.
