Herbicide injuries on blueberry provide suitable infection sites for Neofusicoccum ribis

Abstract

Botryosphaeria dieback of blueberry is caused by several botryosphariaceous species including Neofusicoccum ribis This research investigated whether stem damage caused by three herbicides could allow for penetration of blueberry stems by this pathogen Results showed that all the herbicides damaged hard green shoots of which 100 were penetrated by the inoculated N ribis Mean lesion lengths were similar for all herbicides and the inoculated wounded control (P0240) Isolations from bark and wood showed similar infected proportions for bark (P014) but different proportions for wood (P0035) These mean proportions were 764 for bark and 825 for wood when treated with glufosinateammonium 746 and 750 with paraquatdiquat 669 and 614 with carfentrazoneethyl and 581 and 604 for the inoculated wounded control This study has indicated that herbicide damage can create entry ports for stem pathogens and highlights the importance of careful herbicide application to manage understorey weeds in blueberry farms