TREE-INJECTION: Injection of essential oils as bio pesticides in fruit arboriculture

Apple aphid (Disaphys plantaginea) is responsible for significant yield declines in apple orchards through sap-sucking activities. To manage them, farmers have so far used a wide range of phytosanitary products, sometimes harmful to both environment and human health. Therefore this research aims to develop alternative product based on essential oils injected into the tree vascular system (xylem).
An experimental design in climatic chamber was establish using Jonagold M9 2Y trees, Baxter bags and needles to inject emulsion of Cinnamomum cassia, Mentha spicata and Eugenia caryophyllus essential oils.
To demonstrate the biological activity of these treatments mortality curves were establish using 3 days old larvea of Dysaphis in clip cage.
The phytotoxicity was assessed through eco-physiological measures of chlorophyll fluorescence and photosynthetic activity.
The content kinetics of the major volatile organic compounds (VOCs) of the oils as well as their impact on the rest of the VOCs profile (both contained and emitted by leaves) was performed by thermal desoption and dynamic headspace gas chromatography coupled to mass spectrometry (TDU-GC-MS and DHS-GC-MS).
The results demonstrate 80% death rates after 3days treatments as well as presence of oils compounds within the leaves without significantly impacting the leaf vitality parameters compared to blank treatments. Those results demonstrate the case for essential oil in agricultural practises.