|Authors: ||M. Hoffmann, E.H. Ruehl, L. Huber, G. Eisenbeis, M. Kirchmair|
|Keywords: ||woody root system, small insect parasites, aphids, grape phylloxera, grape rootstocks, Vitis berlandieri × Vitis riparia, Win Rhizo|
In a long-term study (2006-2009) on a vineyard in Rheingau/Germany [‘Riesling’ on V. berlandieri × V. riparia (5C and 125AA)], roots of the top 20 cm soil were extracted monthly (Jan.-Nov.). Morphological root system traits were analyzed digitally (Win Rhizo Pro). Nodosities and phylloxera instars were counted visually (dissecting microscope) on the extracted root fragments.
This study introduces a methodical approach to assess patterns of grape root parasite populations under field conditions quantitatively, using grape phylloxera (Daktulosphaira vitifoliae Fitch) as model.
The aims of the study were: 1. the development of visual nodosity parameters to draw conclusions on root system status; 2. including grape root dynamics into the assessment of grape phylloxera population and nodosities; 3. providing a high sensitivity to temporal population and root development, spatial conditions in field as well as cultivar differences.
The results describe the development of a visual nodosity classification to quantify the impact of grape phylloxera on the root system.
Traits of root system dynamics were included into the assessment method by including root length into instar and nodosity abundance calculations.
To show the sensitivity of the assessment method, temporal, spatial and cultivar differences were statistically reproduced for several parameters.
Download Adobe Acrobat Reader (free software to read PDF files)
URL www.actahort.org Hosted by KU Leuven