ISHS Acta Horticulturae 416: IV International Symposium on Computer Modelling in Fruit Research and Orchard Management
MODELLING THE FRESH MATTER ACCUMULATION FOR PEACH FRUIT GROWTH |
| Authors: | M. Génard, J.G. Huguet, R. Laurent |
| Keywords: | sap flow transpiration, water stress, trunk daily shrinkage, Prunus persica L. Batsch |
| DOI: | 10.17660/ActaHortic.1996.416.11 |
| Abstract:
A model of fresh matter accumulation was developed for peach fruit during the stage of rapid development of the mesocarp. We assumed that trees were optimally fertilized and that carbon acquisition by photosynthesis was sufficient for well irrigated trees to reach full potential fruit growth. The model is based on simple hypotheses of fluid flows into and out of the fruit. We considered that the peach receives a daily sap flow from the plant and releases water and carbon by transpiration and respiration. The model assumes that the sap flow to the fruit increases as the fruit water potential decreases and as the tree water potential increases. The fruit water potential was assumed to decrease essentially in the same way as its osmotic potential, the latter depending on sugar concentration. The model assumes that sugar concentration increases with both fruit weight and transpiration per unit weight. The maximum daily shrinkage of the trunk is used as an indicator of tree water potential. Consequently the model assumes that the sap flow increases with fruit weight along with transpiration per unit weight, and that it decreases with the increase of the maximum daily shrinkage of the trunk. Fruit transpiration was assumed to increase with fruit size, which is related to skin permeability, and with global radiation. Fruit respiration was considered to be related to its growth and to temperature. The model allows simulation of the variability of growth between fruits according to climate conditions, level of water stress and weight of the fruit at the beginning of the simulation. An experiment conducted on trees well watered or submitted to water stress was used partly for estimating the model parameters and partly for testing the model. The close agreement between simulated and field data supported our model. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
