Early detection of phylloxera in grapevines (Vitis vinifera) – A test-bed for spectro-optical and chemical fingerprinting of pest-induced grapevine stress

Abstract

A better means of early detection of grapevine phylloxera infestation was sought because weakening of vines picked up by current remote sensing can be caused by influences other than phylloxera. The industry has sought advances in this area because of the importance of accurate and fast identification to trigger quarantine action.

Summary

The research centred on investigation of whether above-ground symptoms of phylloxera infestation could be detected through analysis of vine leaf pigments using high performance liquid chromotography (HPLC), via leaf and canopy spectral reflectance measurements and analysis of leaf chemical composition using nuclear magnetic resonance (NMR) techniques. Glasshouse as well as field studies were involved. Part of the glasshouse activity was a pilot study to determine the level of phylloxera infestations required to initiate a detectable host plant response to phylloxera (the conclusions of this part of the study helped with implementation of a more comprehensive stress response trial).  A basic part of the work was comparison of images gained from airborne and satellite techniques, along with ground-truthing.

An important finding was that phylloxera-infested and non-infested vines could be separated spectrally by using statistical procedures taking account of pigments involved in photosynthesis and photoprotection, plus other factors.

The value of this research to the industry is that it has indicated potential for using a spectro-chemical response for phylloxera detection that would be an improvement on existing measures.