Evaluation of an indirect method for leaf area index determination in the vineyard: Combined effects of cultivar, year and training system

Authors

  • Nathalie Ollat
  • M. Fermaud
  • J. P. Tandonnet
  • M. Neveux

DOI:

https://doi.org/10.5073/itis.1998.37.73-78

Keywords:

gap fraction, leaf area index, training system, grapevine cultivar

Abstract

The performance of the plant canopy analyzer LAI-2000 was evaluated in three seasons to estimate vineyard LAI (leafarea index) in the Bordeaux area. Measurements were made in a vertical-trellised vineyard with 5555 Semillon and Sauvignon blanc vines per ha, and with 2525 lyre-trained Cabernet franc vines per ha. Various LAI-2000 sampling protocols were tested and the data compared with destructive determinations. While the results from single vines a ere not satisfactory, very good relationships were obtained if five consecutive vines were used. In the vertical-trellised vineyard, a very accurate and direct estimate of LAI could be obtained with the LAI-2000 using a combination of "parallel" and "diagonal" sampling protocol. LAI values obtained by direct and LAI-2000 had a 1:1 correspondence and were identical for both, year and cultivar. For the lyre system, a local calibration was required, mainly because of the contribution of shoots, perennial vine parts and posts. This calibration was easily obtained by progressively removing leaves from the vines.

Downloads

Published

2015-08-05

Issue

Section

Article