© 2001 Heron Publishing—Victoria, Canada
Variation in surface conductance to water vapor diffusion in peach fruit and its effects on fruit growth assessed by a simulation
model
Francoise Lescourret (1), M. Génard (1), R. Habib (1) and Svetlana Fishman (2)
1. INRA, PSH, Domaine St. Paul, Site Agroparc, 84914 Avignon Cedex 9, France / 2. Department of Statistics and Operations Research, The Volcani Center, P.O. Box 6, Bet-Dagan 50250, Israel / Received November 24, 2000
Summary
Surface conductance to water vapor diffusion was measured in individual peach fruits (Prunus persica (L.) Batsch) and plotted as a function of fresh fruit mass for four cultivars. Surface conductance increased with fresh fruit
mass, but the pattern differed with cultivar, and fruit-to-fruit variation occurred. Relationships between fruit mass and
surface conductance were modeled by fitting mathematical equations to the data. The simulation model of Fishman and Génard
(1998) was used to study dry mass and water components of fruit growth (1) when surface conductance varied with fruit size
or was constant, and (2) when surface conductance values were high, moderate or low with respect to fruit mass. Increased
surface conductance with fresh fruit mass resulted in fruit growth cessation. Fruits differing in surface conductance had
similar dry mass. However, under well-watered conditions (stem water potential between –1 and –0.2 MPa), the water balance
components of growth (osmotic and hydrostatic pressure, water potential and water balance) differed greatly and, as a result,
the lower the surface conductance the greater the fresh fruit mass. These differences were buffered under drought conditions
(stem water potential between –2.4 and –0.6 MPa).
Keywords:
fresh mass, hydrostatic pressure, osmotic pressure, transpiration, water potential, water stress.
