Efficacy of peroxygen disinfestants against non-fungal plant pathogens in agricultural and horticultural production: A systematic review and meta-analysis.

Authors: Copes, Warren

Submitted to: Frontiers in Horticulture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/18/2023
Publication Date: 1/10/2024
Citation: Copes, W.E. 2024. Efficacy of peroxygen disinfestants against non-fungal plant pathogens in agricultural and horticultural production: A systematic review and meta-analysis.. Frontiers in Horticulture. 2:1228494. https://doi.org/10.3389/fhort.2023.1228494.
DOI: https://doi.org/10.3389/fhort.2023.1228494

Interpretive Summary: Hydrogen peroxide and peracetic acid compounds have been used to kill plant pathogens for the last 30 years. Many studies have shown these disinfestants to be highly effective, while others have shown moderate to poor efficacy. A systematic literature review was done to obtain an overview of how well these disinfestants have controlled bacteria, fungi, oomycetes, viroids and viruses in production of agricultural and horticultural plant hosts. A meta-analysis was performed to assess overall efficacy and to evaluate the influences of chemical dose, organism taxonomic category, substrate being treated, research quality and statistical significance on efficacy. The most prominent conclusions were a greater portion of fungi and viruses were inactivated by these products than bacteria, and pathogen mortality was higher on plastic surfaces and lower on plant surfaces than on other production and equipment surfaces. Results supported the concept that further information development is needed to improve selection of the proper disinfestant dose relative to the plant pathogen and surface being treated. This analysis provides a broad reference that can be used by researchers, Extension personnel, crop advisors and agricultural and horticultural producers.

Technical Abstract: Peroxygen compounds, such as hydrogen peroxide (HPX) and peracetic acid (PAA), have only been used to disinfest surfaces of plant pathogens in the last 30 years. A systematic review was performed to evaluate overall efficacy of peroxygen compounds specifically against plant pathogens in agricultural and horticultural crop production systems. A meta-analysis was performed with 53 cases involving 25 different plant pathogens that compared peroxygen intervention treatments to a non-treated control's ability to disinfest surfaces. The overall summary effect was a Hedges' g value of -2.27 with 95% confidence limits of -2.71 to -1.83 (P<0.0001) for the random effects model. This indicates that the intervention treatment in most cases caused a significant reduction in viable propagules or disease progression. However, heterogeneity was significant with a range of effect sizes from -12.87 to 0.77. In an effort to explain the heterogeneity, five subgroup analyses were performed evaluating dose, taxonomic organism classification, substrate, publication quality and statistical significance categories. The most prominent conclusions were a greater portion of fungi and viruses were inactivated by peroxygens than bacteria, and pathogen mortality was more difficult to achieve on plant surfaces than on production and equipment surfaces. Confounding issues did exist and are discussed. Heterogeneity was not well explained but was attributed to the broad diversity of pathogens, assessment measurements, surfaces and research protocol in the studies. In conclusion, evidence did not support the concept that a defined dose range of HPX and PAA would provide equal activity against all plant pathogens and on all surfaces. Product labels do provide dose recommendations that differ with application, but a more comprehensive understanding of factors that influence product activity is needed to maximize utility of these disinfestants. This analysis serves as a good reference when considering what is known about HPX and PAA efficacy.