Abstract: To investigate the antifungal activity of the garlic root exudates against Fusarium oxysporum, garlic root exudates were cultured on solid agar, and their main components were determined by gas chromatography- mass spectrometry (GC−MS). Studies on mycelial growth rate and spore germination showed that the inhibition rate of mycelial growth was 30.56%, and the inhibition rate of spore germination of 1 g/mL garlic root exudates was as high as 100.00%. 2,6−diisopropyl phenol and dibutyl phthalate of the main components of garlic root exudates had the highest inhibitory effects on the mycelial growth and spore germination of F. oxysporum. The control effect of dibutyl phthalate was better, after 21 days of inoculation, the disease index was 55.00 at a concentration of 5 mmol/L, and the control effect was as high as 32.38%. The garlic root exudates and its main components had significant inhibitory effects against F. oxysporum. This provides a scientific reference for the development of plant protectants containing garlic and intercropping garlic to control tobacoo Fusarium root rot.

Key words: garlic root exudates, Fusarium oxysporum root rot of tobacco, antifungal activities, control effects