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ARS Home » Midwest Area » East Lansing, Michigan » Sugarbeet and Bean Research » Research » Publications at this Location » Publication #392854
Research Project: Genetic Characterization for Sugar Beet Improvement

Location: Sugarbeet and Bean Research

Title: Effects of grape powdery mildew spray programs on foliar microbial communities in California vineyards

Author
item Yang, Hui-Ching
item Rodriguez Ramos, Jean
item Hale, Lauren
item Naegele, Rachel

Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 5/15/2021
Publication Date: 1/11/2022
Citation: Yang, H., Rodriguez Ramos, J.C., Hale, L.E., Naegele, R.P. 2022. Effects of grape powdery mildew spray programs on foliar microbial communities in California vineyards. Phytopathology. 112(11) Abstract #3340. Plant Health 2022-American Phytopathology Society. Pittsburgh, PA, Aug 6-10, 2022.

Interpretive Summary:

Technical Abstract: Synthetic fungicide treatments for grapevine powdery mildew have been widely applied in the vineyard for decades, yet their impact on non-target microorganisms in the phyllosphere has not been sufficiently studied. The phyllosphere’s microbiome could influence plant health by minimizing disease through surface competition and can affect yield and quality of the fruit. This study aimed to (1) investigate temporal changes in foliar microbial compositions under different fungicide spray programs designed to control powdery mildew, and (2) evaluate the possible impact of the same fungicide sprays on the non-target fungal and bacterial communities. Grapevine leaf epiphytes were collected and characterized at six time points from two vineyards with the same rotating powdery mildew spray programs from May to July in the Central Valley California. Using ITS and 16S rRNA amplicon sequencing, we compared fungal and bacterial/archaeal alpha and beta diversities, taxonomic compositions, and differential abundance of taxa among treatments, locations, and sampling time points. Results showed that location had a significant effect on both bacterial and fungal community compositions. In addition, both bacterial and fungal communities displayed substantial shifts in composition across different time points in the growing season. Functional guilds analysis for fungal communities showed that plant pathogenic fungi increased significantly in the later season. Botrytis, the most important post-harvest pathogen in grapes was significantly more abundant in one of the locations in the late season. However, the overall impact from the different spray programs was not significant.