ISHS Acta Horticulturae 465: IV International Peach Symposium
XYLEMIC, PHLOEMIC AND TRANSPIRATION FLOWS TO AND FROM A PEACH |
| Authors: | J.G. Huguet, M. Génard, R. Laurent, J. Besset, C. Bussi, T. Girard |
| Keywords: | Peach, Prunus persica, fruit growth, fruit quality, water stress, micromorphometry |
| Abstract:
The fresh matter growth of a fruit mainly depends on the balance between the input from the xylemic and phloemic flows and the fruit transpiration output. As the phloemic flow brings sugars, its flow, relatively to the other flows, changes the dry matter content and the quality of the fruit. Simultaneous measurements of the diameter microvariations of three kinds of fruits (control, isolated from photosynthesis and picked one) allow to assess xylemic, phloemic and transpiration flows. Without any water stress the xylemic flow seems to be closely linked to the peach transpiration flow. The fruit transpiration contribution is not essential concerning the fruit growth but is probably consistent concerning the fruit quality. A plastic wrapped fruit shows a lower phloemic flow than the control one. On a water stressed tree there is such a so strong competition for water between leaves and fruits, that during the morning there is an output of water from fruits through the xylemic vessels. In a general way the magnitude of the phloemic flow increases with fruit size and, during the course of the day, reaches its maximum in late afternoon. Xylemic and phloemic flows seem to remain functional until fruit picking. | |
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