Carvacrol: A Promising Environmentally Friendly Agent to Fight Seeds Damping-Off Diseases Induced by Fungal Species

Abstract

Background: Gramineae damping-off disease is a growing problem worldwide, which affects a large range of seedlings in nurseries, glasshouses, gardens, crops, forests and untimely generates a heavy economic impact on the agriculture and related sectors. Objectives: The present study was conducted to evaluate the preventive potential of carvacrol on germination of Fusarium oxysporum, Neocosmospora solani, and Microdochium nivale spores as responsible agents for Lolium perenne seeds damping-off disease. Material and methods: Macrodilution method in agar medium, spore germination, spore destruction, and preventive treatment bioassays were used to achieve this goal. Results: The minimum inhibitory concentration (MIC) of carvacrol vs. tested strains existed in the range of 0.25–0.5 mg/mL. Carvacrol used in concentrations ranging from 0.2 to 0.4 mg/mL inhibited the germination of all fungal spores in a dose-dependent manner. Carvacrol showed a very strong sporicidal effect against all studied fungal strains, and this effect was well confirmed by microscopic observations. The percentage of growth inhibition was found to be strictly correlated to carvacrol dose up vs. all strains. Carvacrol increased the emergence of L. perenne seeds when compared to both uninfested and infested seeds. Conclusion: Based on the results obtained, carvacrol fulfills the requirement for being a natural alternative agent to fight Gramineae seedlings’ damping-off caused by fungal species without adverse effects on the plants.