Interaction of microbial biocontrol agents and fungicides in the control of postharvest diseases

 

 

Giuseppe Lima,* Filippo De Curtis and Vincenzo De Cicco

Department of Animal, Plant and Environmental Sciences - Plant Pathology, University of Molise, Campobasso, Italy

 

 

 

Abstract

Purpose of review: Drawing on several representative studies, this review focuses on the interaction between antagonist microorganisms and fungicides and provides related suggestions for more efficient control of postharvest diseases (PHDs).

Findings: Lack of knowledge of the compatibility of antagonist microorganisms with agrochemicals may contribute to the failure of biocontrol to perform as expected, as pre- and postharvest fungicide applications can affect the survival and population of natural and artificially introduced antagonists on fruits and vegetables. A more rational application schedule of substances that inhibit antagonists would optimise both the colonisation and the efficacy of biocontrol agents (BCAs). The combination or alternation of synthetic fungicides with antagonist microorganisms may enhance and stabilise the efficacy of BCAs. In addition, this strategy may display even better control of resistant strains of fungal pathogens and may enable commercial growers and packinghouses to reduce the amount of fungicides used, thus lowering the amount of chemical residue on marketed products. Combined applications of BCAs with small quantities of fungicides may also reduce the biomass of antagonists and the relative costs of formulation.

Directions for future research: The integration of fungicides with antagonist microorganisms has the potential to make BCAs more attractive for large-scale applications against PHDs. Therefore, compatibility with chemicals is an important factor for more appropriate manipulation/application of naturally occurring antagonists or selected BCAs. However, in environments where fungicide resistance has already reached high levels, use of old fungicides should be suspended or replaced with new effective compounds which should be registered for postharvest treatments. However, integrating BCAs with chemicals remains a necessary prerequisite to optimise the management of PHDs and to maintain effectiveness of existing or new emerging fungicides for as long as possible. Therefore, future research projects should be aimed at both improving knowledge of antagonist-pathogen-fungicide interaction and mechanisms involved.

 

Keywords: antagonist microorganisms; chemical control; fruits and vegetables; fungicide resistance; integrated control; postharvest diseases

 

Stewart Postharvest Review 2008, 1:4

Published online 01 February 2008

doi: 10.2212/spr.2008.1.4