Development, characterisation and efficacy evaluation of biochemical fungicidal formulations for postharvest control of anthracnose (Colletotrichum gloeosporioides Penz) disease in mango

What is it about?

The objectives of the study are to develop and characterise formulations with volatile molecules in an emulsifiable concentrate form, for their antimicrobial properties and to evaluate their efficacies against Colletotrichum gloeosporioides Penz., to control anthracnose in mangoes after harvest.Results showed EC39 and EC40 among formulations were characterised for their excellentemulsification properties, the droplet size of 192.34 ± 0.48 nm and 227.4 ± 0.71 nm and Zetapotential of
52.5 ± 2.76mv and
48.84 ± 2.62 mv, respectively, with better storage stability at10 ± 20 C and RH 80 ± 5%. In vitro assay, 100% inhibition of visual spore germination by 0.15%and 0.2% MIC value for EC39 and EC40, respectively Studies on the efficacy of their fungicideproperties also indicated the IC50 value of 0.161% and 0.162% for EC39 and EC40 respectively, for mycelial growth inhibition. In vivo testing too, EC39 and EC40 effectively controlled anthracnose incidence in mango in a dosage-dependent manner.

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Photo by Bee Naturalles on Unsplash

Photo by Bee Naturalles on Unsplash

Why is it important?

Anthracnose is the major pre, and postharvest disease of mango (Mangifera indica L.) and postharvest losses due to this disease are most significant (Ploetz and Freeman 2009). Anthracnose alone cause 5–20% losses during the postharvest condition (Kamle et al. 2013). Anthracnose is caused by Colletotrichum gloeosporioides Penz. that belongs to Colletotrichum genus of fungi which is one of the most common and unusual plant pathogenic genera that cause diseases on wide range hosts including herbs to trees and their crops. A range of synthetic chemical fungicides has been suggested to control anthracnose disease (Monteon Ojeda et al. 2012). Although many synthetic fungicides were found to control anthracnose disease effectively, their indiscriminate applications led to the development of fungicide resistance in several fungal species including Colletotrichum sp. The compulsive use of synthetic fungicides has caused different types of environmental and toxicological problems, such as environmental pollution and health-illness. Therefore, there is a crucial need to find out a sustainable and eco-friendly alternative to address concerned issues (Chung et al. 2006). An array of eco-friendly methods and unfriendly bacteria as biological control methods have been applied to mitigate anthracnose disease caused by C. gloeosporioides (Park et al. 2012, Sang et al. 2013). Much of the anti-fungal research on control of anthracnose by using various medicinal and aromatic plant extracts or essential oils have been critically reviewed and no work on identification, in vitro screening and testing of specific volatile compounds against Colletotrichum species of anthracnose, for their individual and synergistic fungistatic and fungicidal effects and in vivo studies to test their efficacy as a biochemical fungicide in various formulations against targeted species of genus Colletotrichum of anthracnose as the alternative to synthetic chemical fungicides were reported (Kobaisy et al. 2001, Wang et al.2005, Abd-Alla and Haggag 2013, Hong et al. 2015).The application of plant essential oils and their volatile constituents could decrease the anthracnose incidence on these subtropical fruits (Wang et al. 2005). However, development of formulations using specific volatile molecules in emulsifiable concentrate form, and its evaluation in terms of characteristics, emulsion stability, shelf life and antifungal activity against C. gloeosporioides in tropical fruits have not reported.

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