Effects of fungal root infection on the vigor of grapevines infested by root-feeding grape phylloxera

Authors

  • A. D. Omer
  • J. Granett
  • J. A. De Benedictis
  • M. A. Walker

DOI:

https://doi.org/10.5073/vitis.1995.34.165-170

Keywords:

grape phylloxera, Daktuloshaira vitifoliae, damage, secondary fungi, infection, Vitis vinifera, grapevine

Abstract

The role of fungal pathogens in damage of grapevines (Vitis vinifera L.; cv. Chardonnay) associated with grape phylloxera (Daktulosphaira vitifoliae FITCH) was investigated. Seven different genera of secondary fungi were isolated from surface-disinfected feeding sites of phylloxera but none from surface-disinfected root tissues undamaged by phylloxera. Damage in vines infested with phylloxera and infected with Fusarium solani (MART.) or with F. solani and Pythium ultimum TROW. was significantly greater than damage in vines infested with phylloxera only. In a greenhouse experiment, total biomass was reduced by 16% in vines infested with phylloxera and 24 to 29% in vines infested with phylloxera and infected with fungus in comparison with control vines. Chlorophyll content, average internode length, shoot biomass, and root biomass in the uninfested, uninfected vines were significantly greater than vines infested with phylloxera or vines infested with phylloxera and infected with F. solani or P. ultimum, or both. Preventative treatment with metalaxyl, benomyl or copper quinolinolate fungicides significantly decreased damage in phylloxera-infested vines in comparison with untreated vines. The implications of this research with respect to management of grape phylloxera are discussed.

Downloads

Published

2015-08-14

Issue

Section

Article