Alternative Management Approaches of Citrus Diseases Caused by Penicillium digitatum (Green Mold) and Penicillium italicum (Blue Mold).

Usha K Bhatta

doi:10.3389/fpls.2021.833328

Abstract

Green mold (Penicillium digitatum) and blue mold (Penicillium italicum) are among the most economically impactful post-harvest diseases of citrus fruit worldwide. Post-harvest citrus diseases are largely controlled with synthetic fungicides such as pyrimethanil, imazalil, fludioxonil, and thiabendazole. Due to their toxic effects, prolonged and excessive application of these fungicides is gradually restricted in favor of safe and more eco-friendly alternatives. This review comprehensively describes alternative methods for the control of P. digitatum and P. italicum: (a) antagonistic micro-organisms, (b) plant extracts and essential oils, (c) biofungicides, (d) chitosan and chitosan-based citrus coatings, (e) heat treatments, (f) ionizing and non-ionizing irradiations, (g) food additives, and (h) synthetic elicitors. Integrating multiple approaches such as the application of biocontrol agents with food additives or heat treatments have overcome some drawbacks to single treatments. In addition, integrating treatment approaches could produce an additive or synergistic effect on controlling both molds for a satisfactory level of disease reduction in post-harvest citrus. Further research is warranted on plant resistance and fruit-pathogen interactions to develop safer strategies for the sustainable control of P. digitatum and P. italicum in citrus.

Highlights

The citrus family Rutaceae primarily comprises sweet oranges, mandarins, grapefruit, kumquats, lemons, limes, and pummelos
The results indicated that these essential oils inhibited both pathogens’ growth/colony diameter over untreated PDA plates and reduced decay loss in storage; lemon grass oil produced the most potent effect (Jhalegar et al, 2015)
Aqueous “Natamycin” treatments followed by fruit coating reduced the incidence of decay from P. digitatum to

Summary

Introduction

The citrus family Rutaceae primarily comprises sweet oranges, mandarins (tangerines), grapefruit, kumquats, lemons, limes, and pummelos. Use of essential oils to control citrus green and blue mold is gaining importance, thanks to antimicrobial and antioxidant properties, synergistic effects, presence of active compounds, and low residue levels (Tripathi and Dubey, 2004; Bakkali et al, 2008).

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Results

Conclusion