Citrosol identifies fungicide resistant spores more quickly and provides recommendations to control Cladosporium

In Peru – within the framework of this technical reference forum for producers, exporters and sector professionals from around the world – Dr. Celia Murciano, a biologist from Citrosol, gave a presentation on the pathogens relevant to quarantined shipments of citrus, and control of resistant strains.

“During the presentation, the key biological aspects of the types of decay that develop during long-distance refrigerated transport were discussed, as well as the most appropriate protocols and treatments for their mitigation. Due to its unusually high incidence found on certain varieties of mandarin in refrigerated shipments from Peru last season (2017-2018), emphasis was placed on decay caused by Cladosporium sp. Finally, the importance of the evaluation and control of resistance to fungicides in warehouses was discussed, taking as an example the resistance monitoring program that Citrosol applies to its customers pretty much everywhere around the globe”, confirmed Citrosol’s head of Microbiology.

The Resistance Monitoring Program

An event, held on the other side of the Atlantic, that stood out for its high level technical content, in which participants, speakers and exhibitors have all interacted, and where Citrosol was given the opportunity to present operators with an action strategy to anticipate the problem and ‘cut out’ resistance early.

Citrosol’s resistance monitoring program undertakes site samples at clients’ facilities. These are systematic, programmed, samples and if decay issues are noted, Citrosol evaluates the resistance to fungicides of P. digitatum and P. italicum in isolation.

The decay promoting pathogen is identified by molecular techniques with resistance to fungicides and the possibility of resistant strains being determined according to the mutation they cause. For example, the time required to identify pathogens and assess resistance to IMZ drops from 15 days to just 1-2 days. “Over the two day seminar we had numerous meetings with clients, where we were able to more fully address the topics covered in the presentation, answer technical queries and resolve any lingering doubts,” added Raúl Perelló, Citrosol’s International Director

Recommendations to combat Cladosporium

Although Citrosol undertook research surrounding the problem experienced by W. Murcott, Tango and Nadorcott in their end-of-season shipments last year, results were inconclusive; the involvement of the Cladosporium ramotenellum fungus was identified. In consequence, the scientific team at Citrosol are recommending that, to minimize this problem, it would be necessary to reinforce cleaning and disinfection protocols throughout the season, both on the lines and in storage areas and particularly before commencing work with any of the more susceptible varieties.

Celia Murciano also delved into the cleaning and disinfection of field crates to avoid transmission of Cladosporium from the field to the warehouse or vice versa. To resolve this problem, a drencher with Citrocide Plus is invaluable.

“Boost the dose of Citrocide when washing the fruit (Citrocide System on line)“, outlined the biologist, “strengthen the drencher treatment with Ortocil at 1200 ppm and with Citrocide Plus, as, in vitro, they are effective against Cladosporium ramotenellum, and reinforce the wax treatment with Orthophenylphenol (Ortosol 6500 to 3575 ppm); A fungicide proven to be effective against peduncular mold caused by Cladosporium sp., so one that should help mitigate C. ramotenellum infection. “