Evaluation of a oxygenate based plant protection treatment in viticulture against fungal diseases

Abstract

Over the last decades the use of pesticides in vine protection, e.g. copper is under severe discussion and is becoming a major concern in viticulture. Since the effectiveness of oxygenates against various microorganisms had been proven in the medical field a strategy for oxygenate-based plant protection was developed and evaluated over three vintages. The production of the oxygenate is following the Criegee-mechanism using O3 and unsaturated natural plant derived fatty acids forming so called ozonides. Therefore the effect of the treatment has been evaluated in a holistic approach, covering the efficiency against fungal diseases, protection of desired beneficial insects, the micro flora, various secondary metabolites of the grapevine and the resulting sensory profile of the wines. The biological effectiveness has been measured by using different in-vivo and in-vitro studies. The influence on desired berry compounds, e.g. anthocyanins, have been determined by classical GC-MS and HPLC methods. Positive effects against downy and powdery mildew could be demonstrated. No negative effects against insects, naturally occurring microorganisms, and desired berry compounds were observed. Even spontaneous fermentation was not inhibited. Quantitative descriptive sensory analysis as well as CATA/RATA showed no negative effect of the treatment.