The efficacy of some endophytic fungi against primary grapevine black foot disease pathogens

Abstract

ABSTRACT Black foot disease (BFD), primarily attributed to taxa within the genera Dactylonectria and Ilyonectria, is a significant problem that causes serious damage worldwide in many grape and wine regions. This threat could especially be destructive in nurseries and early-stage vineyards, where it induces a decline in growth along with drying, leading to a reduction in the quality and lifespan of the grapevines. This research mainly focused on assessing the biocontrol capabilities of endophytic isolates derived from grapevine saplings, specifically Acremonium sclerotigenum and Clonostachys rosea. The study aimed to assess their effectiveness against the major pathogens responsible for BFD, including Dactylonectria macrodidyma, D. torresensis, and I. liriodendri, under laboratory and in vivo conditions. In the conducted paired culture assays, Trichoderma harzianum KRL-AG2 was employed for comparative purposes. On the 28th day of antagonistic tests, the inhibition response of A. sclerotigenum (≥94%) and C. rosea (>90%) isolates against the three species of BFD, D. macrodidyma, D. torresensis, and I. liriodendri, reached the maximum inhibition rate. Based on the in vivo analysis conducted with 1103 P rootstocks, T. harzianum, A. sclerotigenum, and C. rosea isolates significantly reduced the disease severity and supplied notable positive effects on plant growth parameters, including root dry weight, root length, and shoot dry weight. These results suggest that these biocontrol agents have potential for the biological management of BFD.