Plant Pathology Science

Introduction: Gray mold caused by Botrytis cinerea is the most important disease after strawberry fruit harvest. The use of chemical fungicides can have a negative effect on the health of consumers, so the use of plant essential oils for disease management has been considered. The effect of six plant essential oils on the pathogen and the contamination of strawberry fruits was investigated in this research to identify suitable essential oil to control the disease. Materials and Methods: The pathogen was isolated from infected strawberry fruits in northeastern Iran. The inhibitory effect of different concentrations of peppermint, savory, caraway, cumin, eucalyptus and thyme essential oils on mycelial growth and germination of the pathogen spores was tested by mixing them with culture medium. Then, the effect of these essential oils in liquid and vapor phases on the contamination of strawberry fruits was tested. After normalization, the data of these experiments were analyzed by analysis of variance with MSTAT-C software and the means were compared with Duncan test. Results: Essential oils of caraway and eucalyptus had the greatest effect in inhibiting the growth of pathogen mycelium. Essential oils of caraway, cumin, savory, thyme and peppermint had the greatest effect in inhibiting the germination of pathogen spores. The essential oils of caraway, cumin, savory, thyme and peppermint in the vapor phase, the essential oils of caraway and eucalyptus in the liquid phase, prevented further contamination of the fruit. Conclusion: The findings of this study show that all of these plant essential oils can significantly prevent the growth of mycelium and germination of pathogen spores and contamination of strawberry fruits, but the effect of caraway essential oil in most cases is better than others. Thus, it can be used as an alternative to fungicides on strawberry fruit.

Apple postharvest diseases are usually caused by a wide range of pathogenic fungi. Postharvest rot of this crop is one of the most important economic diseases and also one of the main factors in reducing the lifespan of this crop. In contrast, our current knowledge of the occurrence and latent contamination during storage and its epidemiology is limited. The pathogenic fungi Botrytis cinerea and Penicillium expansum causing gray mold and blue mold, respectively, are the most common pathogens in the cultivation areas, which are usually inhibited by the use of synthetic fungicides. However, due to the growing concern over the use of synthetic fungicides, alternative control measures such as using physical treatments, natural compounds, and biocontrol agents are highly desired. Although no method has been approved as a definitive method of postharvest diseases management, the effectiveness of yeasts such as Candida saitoana, bacteria such as Rahnella aquatilis, and fungal species such as Trichoderma harzianum has been suggested.

Rose is the most important cut flower in the world. Dieback is one of the most devastating rose diseases in greenhouses. The main symptom of the disease is dryness of the branch tips and lack of flower formation. The disease causal agents are Coniothyrium fuckelii, Botryodiplodia theobromae, Botrytis cinerea, Trichothecium roseum, Acremonium sclerotigenum, Diplodia rosarum, Lasiodiplodia pseudotheobromae, Phomopsis sp., and Pestalotia funereal. Disease management methods include cutting the top of the knot at an angle with the least remaining of the deadwood tissue to accelerate the formation of callus tissue, chemical protection of pruning wounds with fungicides, disinfection of the garden knife after each cut, avoiding wounds on the stems and compliance with greenhouse sanitation are described in this article.