MODELLING THE ASSIMILATE TRANSFER AND FRUIT GROWTH IN PEACH TREE

We developed a model of fruit growth with emphasis on the transfer of assimilitates in the shoot bearing fruits in peach (Suncrest GF 677). The shoot was made of compartments connected to the source compartments (leafy shoot) and to the sink compartments (fruits). Each metamer (node and internode) constituted a compartment of the shoot.
The fruit was constituted of a transfer compartment (cytoplasm) and a storage compartment (vacuole) The considered physiological processes were photosynthesis, respiration of fruits and leaves, transfer of assimilates and fruit growth.
Assimilate production was regulated by solar radiation and sink demand.
Assimilate transfer, a function of the assimilate gradient, was induced from the more highly concentrated compartment to the lower one, except for the fruit compartments where transfer was possible whatever the gradient between them might be.
Transfer of assimilates between two compartments was modelled by means of a parametric function.
Fruit respiration depended on the quantity of assimilates entering into it, on its weight and on air temperature.
Fruit growth was the difference between its assimilate supply and its respiration losses.
The assimilate concentration in compartments was computed every three minutes during the period of mesocarp growth.
The simulations reproduced the effect of the number of leaves to fruit ratio on fruit growth fairly well.
This model could be an exploratory tool to analyse source-sink relationships and the effect of practices such as fruit thinning.

IV International Symposium on Computer Modelling in Fruit Research and Orchard Management

C. Bruchou, M. Génard

https://doi.org/10.17660/ActaHortic.1996.416.10