Abstract
Grapevine is highly susceptible to fungal diseases, whose incidence and severity increase due to climate change. The present work focuses on the assessment of eight combinations of natural products with chitosan oligomers with fungicidal capacity that may be effective in the integrated control of powdery mildew, in compliance with Article 14 of the European Directive 2009/128/EC. Their efficacy was evaluated in field conditions against natural infections, in a plot with high disease pressure during a growing season (assaying both foliar or root application), and against overwintering inoculums (chasmothecia) through in vitro tests. In addition, their possible biostimulant capacities were evaluated based on harvest yields. Treatments based on chitosan oligomers in combination with secondary metabolites of Streptomyces spp. and chitosan oligomers combined with hydrolyzed gluten showed the best results in terms of disease control. Given the high efficacy of these formulations, comparable to that of conventional antifungals, they constitute an interesting alternative for the control of this disease whose treatment can, in some cases, represent almost half of the production costs.
Highlights
Grapevine (Vitis vinifera L.) is highly susceptible to numerous diseases caused by aerial pathogens, such as powdery mildew (Erysiphe necator Schwein., synonym Uncinula necator (Schwein.) Burrill), downy mildew
From the results of Friedman’s test (Table S3), it was observed that the lowest degree of attack corresponded to root-applied Chitosan oligomers (COS) + S. lavendofoliae metabolites treatment (T5R)
Numerous species have been described for controlling mildews in different crops, either by direct application or using substances produced by these bacteria [17,28,29,30], but powdery mildew in grapevine has been less widely addressed [31]
Summary
Grapevine (Vitis vinifera L.) is highly susceptible to numerous diseases caused by aerial pathogens, such as powdery mildew (Erysiphe necator Schwein., synonym Uncinula necator (Schwein.) Burrill), downy mildew The incidence and severity of these diseases are increasing as a consequence of climate change [2,3], and, in France, it has been estimated that their treatment accounts for about half of the production cost. The pressure of these diseases forces the use of enormous quantities of phytosanitary products, which entails high economic and environmental costs and, in many cases, quickly generates resistance [4]. According to Eurostat data, the application of phytosanitary products per hectare per year in viticulture is the highest of all crops [5]. In a study on pecuniary and nonpecuniary costs of managing powdery mildew in California grape production, Sambucci et al [7] estimated that powdery mildew control accounted for 89% of crop protection applications in this sector
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
