Origanum vulgare essential oil vapour impedesBotrytis cinerea development on grapevine (Vitis vinifera) fruit

From Firenze University Press Journal: Phytopathologia Mediterranea

Botrytis cinerea infections of Vitis spp. fruits cause major economic losses, and grape producers rely on synthetic and copper-based fungicides for control of this pathogen.

These pesticides present risks for human health and the environment. Implementation of low-impact disease management solutions is important for improving sustainability of viticulture industries. This study investigated the effects of Origanum vulgare (oregano) essential oil (EO) as an antifungal agent.

In vitro and in vivo experiments with B. cinerea were carried out using a vaporization system to circumvent drawbacks of direct EO application. In vitro experiments confirmed the effectiveness of EO vapour treatments, which gave 100% inhibition of B. cinerea growth. Treatment of V. vinifera cv. Chasselas berries resulted in a 73% reduction in fungal growth, confirming the efficacy of the oregano EO vapour for control of grey mould caused by B. cinerea.

This study has demonstrated the efficacy of EOs in the vapour phase on grape berries, which provides new possibilities for development of in-field or greenhouse vaporization systems that can reduce the use of synthetic and copper-based fungicides.

Fungicides represent 49% of the pesticides utilized in the European Union (European Commission Eurostat, 2007). The viticulture industry contributes to this high fungicide use via efforts to control vineyard diseases caused by fungi, including Botrytis cinerea, Plasmopara viticola and Erysiphe necator. This is a growing problem, due to the possible negative impacts on consumer and producer health and on the surrounding ecosystems and soils (Komáreket al., 2010; Aminifard and Mohammadi, 2012).

Botrytis cinerea is an important fungal pathogen in viticulture and in other crops. This pathogen causes grey mould (Naegele, 2018) and Botrytis bunch rot. Botrytis cinerea infections cause major economic losses (Elmer and Michailides, 2007) due to reductions in grape yields and quality (Jacometti et al., 2010; Paňitrur-De La Fuente et al., 2018). Due to the high frequency of usage and possible detrimental health and environmental impacts of pesticides, alternative disease management strategies are required to reduce pesticide use for sustainable agriculture.Alternatives to pesticides include measures to increase plant and fruit resistance to B. cinerea and other fungal diseases, and cultural practices to encourage the maintenance of unfavourable habitats for pathogen development. Cultural practices in viticulture include maintenance of good vine canopy structure, the grow-ing of cover crops and mulching to reduce excessive vine vigour.

However, these practices can be challenging and only marginally effective. Other alternatives include the use of biological control agents and plant extracts, all of which have shown some efficacy for control of B. cinerea, and are typically applied in conjunction with other control methods (Jacometti et al., 2010). Interspecific cross-breeding of naturally disease-resistant varieties is also a very cost-effective, environmentally-friendly solution for the control of fungal diseases. However, challenges regarding the marketing of disease-resistant varieties, such as labelling concerns and varietal reputation, are important when assessing the economic viability and future of new varieties (Fuller et al., 2014). Recent research suggests that essential oils (EOs), with antifungal capacities and low environmental impacts, could be alternatives for control of fungal fruit pathogens. Development of EO treatments for fungal disease management could solve the environmental and human health issues caused by pesticide-based disease management.

DOI: https://doi.org/10.14601/Phyto-11605

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