The efficacy of 8-hydroxyquinoline derivatives in controlling the fungus Ilyonectria liriodendri, the causative agent of black foot disease in grapevines.

Aim: The purpose of this study was to evaluate the in vitro and in vivo efficiency of derivatives of 8-Hydroxyquinoline (8HQ) in controlling the fungus Ilyonectria liriodendri.

Methods And Results: The in vitro tests consisted of assessing its susceptibility to the minimal inhibitory concentration (MIC) and the inhibition of mycelial growth. While the in vivo tests consisted of applying and assessing the most effective products for the protection of wounds, in both preventive + curative and curative forms. The MIC values for PH 151 (6·25 µg ml ) showed better results when compared to the fungicides tebuconazole (>50 µg ml ) and mancozeb (12·5 µg ml for strain 176 and 25 µg ml for strain 1117). PH 151 significantly inhibited mycelial growth, while mancozeb did not differ from the control. In in vivo tests, PH 151 again demonstrated excellent results in vitro, especially when applied preventively.

Conclusions: The derivative of 8HQ PH 151 was effective in controlling the fungus I. liriodendri in vitro and proved to be a promising option for protecting wounds.

Significance And Impact Of The Study: This study points to the prospect of an effective and safe preventive antifungal product, which would enable the use of pesticides in vine culture to be reduced.