On the Applicability of Chitosan Oligomers-Amino Acid Conjugate Complexes as Eco-Friendly Fungicides against Grapevine Trunk Pathogens

In a context in which the incidence and severity of grapevine fungal diseases is increasing as result both climate change modern management culture practices, reducing excessive use phytosanitary products viticulture represents major challenge. Specifically, trunk (GTDs), caused by several complexes wood decay or xylem-inhabiting fungi, pose challenge to vineyard sustainability. this study, efficacy chitosan oligomers (COS)–amino acid conjugate against three species belonging Botryosphaeriaceae family (Neofusicoccum parvum, Diplodia seriata, Botryosphaeria dothidea) was investigated vitro planta. tests led EC50 EC90 effective concentrations 254.6?448.5 672.1?1498.5 µg·mL?1 range, respectively, depending on amino involved complex (viz. cysteine, glycine, proline tyrosine) pathogen assayed. A synergistic effect between COS acids observed D. seriata B. dothidea (synergy factors up 2.5 2.8, according Wadley’s method). The formulations based that showed best inhibition rates, COS?tyrosine, were further greenhouse trial grafted vines two varieties (”Tempranillo” 775P “Garnacha” 110R rootstock), artificially inoculated with mentioned species. planta bioassay revealed chosen induced significant decrease disease N. parvum dothidea. summary, reported may be promising enough worthy additional examination larger field trials.