Response of 'Merlot' (<i>Vitis vinifera</i>) grapevine to defoliation caused by downy mildew (<i>Plasmopara viticola</i>) during the following growing season

Authors

  • M. Jermini
  • P. Blaise
  • C. Gessler

DOI:

https://doi.org/10.5073/vitis.2010.49.161-166

Keywords:

reserves, growth, yield, epidemic

Abstract

The downy mildew (Plasmopara viticola) epidemics on leaf canopy during the ripening phase causes a stress situation for the grapevine. The plant compensates the carbohydrate request of the berries mobilising the carbohydrate reserves stored in the woody parts. In this fourth study the impact of the reserves reduction on the growth and fertility and the recovering capacity of the plant were analysed during two consecutive periods of two years (first year = stress; second year = recovering). Two treatments were compared: “Untreated canopy” (to prevent quantity losses, the clusters were treated once with a contact fungicide at the discovery of the first downy mildew sporulation) and “Standard schedule” (schedule normally applied in the vineyard). The impact of decreased reserve contents in the following growth season has negatively influenced only the shoot elongation and the potential crop yield quantity of the “Untreated canopy” treatment. Nevertheless, a single recovery year was enough to rebuild the reserve pool particularly in the roots, confirming the acclimation potential of the grapevine.

 

Downloads

Published

2015-04-08

Issue

Section

Article