INFLUENCE OF CANOPY MANAGEMENT ON MICROCLIMATE AND PHOTOSYNTHESIS - FIRST CONSEQUENCES ON APPLE PRODUCTION

A. Carbonneau, J.M. Lespinasse
A general experiment on canopy management of apple trees was planted in 1983 in a deep alluvial soil near Bordeaux. The main varieties are Golden Delicious and Royal Gala grafted onto M26. The major treatments are the shape or the inclination of the vegetation and the number (1 or 2) of axes, in factorial combination. That represents 14 different training systems. The most representative ones are :

AV : the classical vertical or french axis (non-stopped leader)
DAV : double vertical axis within the row
Y : double inclined axis across the row (similar to the Tatura trellis)
MIA30 : 1 or 2 inclined axes within an inclined trellis disposed as the   M.I.A.
PERG : 1 or 2 horizontal axes within an horizontal trellis (similar to a   Pergola or the Lincoln canopy)
DAH : 1 or 2 horizontal axes within the row (basic structure of the Solen)

Some ecophysiological measurements were made in July 1987 : PFR (Photon Fluence Rate) profiles at different levels of those canopies, and at the same time net photosynthesis on a huge and representative sample of leaves (Li Cor 6000). An estimation of plant leaf area was made by collecting all the leaves of representative trees and measuring their dry weight. Classical observations on trunk diameter, crop weight, fruit size, maturity and colour were also made.

It appears that the training systems showing the best values of total exposed leaf area and potential photosynthesis were : DAV, MIA30, Y, AV; thereafter DAH; finally PERG.

The parameter which best explained the first agronomical results seems to be the exposed horizontal leaf area per tree (WLE), based on measurements of horizontal projection of the canopy and of mean PFR inside the canopy.

The relative performance of horizontal canopies and vertical axis systems are discussed. Another idea of ecophysiological interest the "Arch system" for canopy management of fruit trees is proposed, and will be improved and studied in the future.

Carbonneau, A. and Lespinasse, J.M. (1989). INFLUENCE OF CANOPY MANAGEMENT ON MICROCLIMATE AND PHOTOSYNTHESIS - FIRST CONSEQUENCES ON APPLE PRODUCTION. Acta Hortic. 243, 185-194
DOI: 10.17660/ActaHortic.1989.243.22
https://doi.org/10.17660/ActaHortic.1989.243.22

Acta Horticulturae