Efficacy of Peroxygen Disinfestants Against Fungal Plant Pathogens: A Systemic Review and Meta-Analysis.

Authors: Copes, Warren; OJIAMBO, PETER - North Carolina State University

Submitted to: Crop Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/31/2022
Publication Date: 1/4/2023
Citation: Copes, W.E. and Ojiambo, P.S. Efficacy of peroxygen disinfestants against fungal plant pathogens. A systematic review and meta-analysis. Crop Protection 164:106143. 2023. https://doi.org/10.1016/j.cropro.2022.106143.
DOI: https://doi.org/10.1016/j.cropro.2022.106143

Interpretive Summary: Peroxygen compounds are a class of disinfestants used to eliminate fungal plant pathogens present on tools, equipment and production surfaces in agricultural and horticultural crop systems. While these products are generally effective, no broad-scale studies have been done to evaluate how consistently these disinfestants achieve proper control. Meta-analysis provides a way to evaluate the efficacy of peroxygen products across a population of studies and determine if efficacy is equal for all application methods and pathogen fungal genera being treated. The analysis demonstrated peroxygen compounds were highly effective on average but differences in efficacy were associated with the material treated and the peroxgen compound applied, and possibly the fungal genera targeted. For example, peroxygen compounds achieved higher control on seeds than on plastic, fruit and plant surfaces. Furthermore, control ranged from being ineffective to highly effective, indicating additional factors not present in the studies may influence efficacy of peroxygen compounds. This research establishes a base-level of information for development of future research but also will be useful to agricultural and horticultural producers needing to select peroxygen products for control of plant pathogens.

Technical Abstract: Peroxygen compounds, such as hydrogen peroxide, peracetic acid and potassium peroxymonosulfate, have been used as disinfestants in agricultural and horticultural operations for about 30 years. This systematic review was performed to investigate overall efficacy of peroxygen compounds against fungal plant pathogens. A meta-analysis was performed to evaluate the biocidal activity of peroxygen intervention treatments compared to a non-treated controls against 20 fungal plant pathogens in 95 studies. The overall summary effect was a high Hedges' g value of 3.48 with 95% confidence limits of 3.02 to 3.93 (P < 0.0001) for the random effects model and indicates peroxygen compounds in most cases cause a high reduction in viable propagules or disease progression. Yet, heterogeneity was also high with 88.9% of the total variance accounted for by true variance and a high between-study variance of 3.71. To understand what influences heterogeneity, subgroup analyses were performed on the categorical moderator’s of fungal genera, target materials and peroxygen active ingredients (a.i.); and two-variable meta-regression analyses were performed with the continuous moderators of peroxygen dose and/or contact time and the three categorical moderators. Subgroup analyses showed differences between target materials (P = 0.0151) and peroxygen a.i. (P = 0.0101) but not between fungal genera (P = 0.1753). Meta-regression results concurred with subgroup analysis results. Models with target materials and dose (P = 0.0115) or time (P = 0.0122) accounted for 8 and 9% of the true variance, respectively. Models with peroxygen a.i. and dose (P = 0.0061) or time (P = 0.0093) accounted for 5 and 4% of the true variance, respectively. Thus, heterogeneity was only partly explained by the moderators evaluated and partly attributed to factors not evaluated in the analyses, such as diversity of research protocol, assessment measurements, sample size and small-study bias. The results support that the current doses and contact times recommended for peroxygen compounds will generally be effective at controlling fungal plant pathogens in agricultural and horticultural production systems. Results also indicate that efficacy of peroxygen compounds against fungi can be affected by the target material being treated and the peroxygen a.i. applied and potentially by fungal genus. This analysis serves as a base reference for considering efficacy performance of peroxygen compounds.