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.

During the postharvest period, citrus fruits are exposed to Penicillium italicum, Penicillium digitatum, and Geotrichum candidum. Pesticides such as imazalil (IMZ), thiabendazole (TBZ), orthophenylphenol (OPP), and guazatine (GUA) are commonly used as antifungals. Glyphosate (GP) is also used in citrus fields to eliminate weed growth. The sensitivity of fungal pathogens of citrus fruit to these pesticides and 1,8-cineole was evaluated, and the effect of GP on the development of cross-resistance to other chemicals was monitored over a period of 3 weeks. IMZ most effectively inhibited the mycelial growth and spore germination of P. digitatum and P. italicum, with minimum inhibitory concentrations (MICs) of 0.01 and 0.05 mg/mL, respectively, followed by 1,8-cineole, GP, and TBZ. 1,8-Cineole and GP more effectively inhibited the mycelial growth and spore germination of G. candidum, with minimum inhibitory concentrations (MICs) of 0.2 and 1.0 mg/mL, respectively, than OPP or GUA. For the spore germination assay, all substances tested showed a total inhibitory effect. Subculturing the fungal strains in culture media containing increasing concentrations of GP induced fungal tolerance to GP as well as to the fungicides. In soil, experiments confirmed that GP induced the tolerance of P. digitatum to TBZ and GP and the tolerance of P. italicum to IMZ, TBZ, and GP. However, no tolerance was recorded against 1,8-cineole. In conclusion, it can be said that 1,8-cineole may be recommended as an alternative to conventional fungicides. In addition, these results indicate that caution should be taken when using GP in citrus fields.