Effect of Ozone Exposure on Phytopathogenic Microorganisms on Stored Apples

Carmen Puia,Veronica Florian,Ioan Oroian

doi:10.34101/actaagrar/15/3350

Carmen Puia, Veronica Florian + Show 1 more

Open Access

https://doi.org/10.34101/actaagrar/15/3350

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Abstract

The aim of our study was to clarify the effect of ozone exposure on several phytopathogenic fungi on stored apple fruits under different storage conditions. The study was conducted at Bistrita, Romania, in the storehouse of an experimental apple orchard in 2002 and 2003. Two widely grown apple cultivars (‘Jonathan’ and ‘Golden Delicious’) were used. General microbial examination of the fruits was made during storage in order to identify the most important storage pathogens. Efficacy of six ozone treatments was evaluted on fruit decay caused by phytopathogenic fungi. Monthly observations (January, February, March and April) were made of the degree of decay and three measurements were assessed (disease frequency, disease intensity and degree of attack). Our results showed that the most important phytopathogenic fungi during storage was blue mold, caused by species of Penicillium. Disease frequency of apple fruits was very high on cv. ‘Jonathan’, much higher than on cv. ‘Golden delicious’. Ozone treatments (25 ppm ozone for 0.5 and 1.5 hours in November) caused significantly lower disease incidence on stored apple than all other ozone treatments. For longer storage, it seems that additional ozone treatments in February increased treatment efficacy. Cv. ‘Golden delicious’ seemed to be more resistant to storage diseases than cv. ‘Jonathan’ both on the untreated and treated fruits. The effect of the ozone treatments was also the most effective when 25 ppm ozone was applied for 0.5 and 1.5 hours in November.

Highlights

During fruit storage, a depreciation of fruit quality occurs due to the metabolic processes inside the fruit and the negative activity of pathogen microorganisms (Mari et al, 2003)
Several studies deal with the effect of ozone on fungal pathogens in storage; these disagree on the effectiveness of ozone on phytopathogenic microorganisms
Pathogens which originated from the field are the following: Spilocaea pomi (Venturia inaequalis), Monilia fructigena (Monilinia fructigena), Gloeosporium fructigenum (Glomerella cingulata) and Sphaeropsis malorum (Physalospora cydoniae)

Summary

Introduction

A depreciation of fruit quality occurs due to the metabolic processes inside the fruit and the negative activity of pathogen microorganisms (Mari et al, 2003). Fungi pathogens cause considerable losses during storage, which results in lower fruit quality and lower market prices (Crişan, 1973; Spotts and Cervantes, 1992; Smilanick et al, 2002). Several fungal pathogens such as Monilia spp., Botrytis spp., Fusarium spp., Rhizopus stolonifer, Trichotecium roseum, Mucor spp., Penicillium spp., Gloeosporium spp., Sphaeropsis spp. and Phomopsis spp. can cause serious storage damage to fruits if storage temperature or relative humidity is higher than required (Spotts and Cervantes, 1992; Perez et al, 1999; Skog and Chu, 2001; Palou et al, 2001; van Leeuwen et al, 2002; Smilanick et al, 2002; Holb, 2003, 2004; Mari et al, 2003). Other studies (Perez et al, 1999; Smilanick et al, 2002; Palou et al, 2002) reported that ozone had little or no effect on e.g. green and blue molds on stored citrus fruit

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