Scientists at University of Minho in Portugal believe they may have found another way to tackle Witches’ Broom Disease, which affects many countries that grow cocoa.
Plant diseases caused by fungal pathogens are responsible for major crop losses worldwide, with a significant socio-economic impact on the life of millions of people who depend on agriculture-exclusive economy. This is the case of the Witches’ Broom Disease, which is caused by the basidiomycete fungus Moniliophthora perniciosa.
The methods used to contain the fungus mainly rely on chemical fungicides, such as copper-based compounds. Not only are they often ineffective, but their utilization is increasingly restricted by the cocoa sector, in part because it promotes fungal resistance, in part related to consumers’ health concerns and environmental awareness.
The disease can also be controlled to some extent by phytosanitary pruning, and the fungus maintains persistent inoculum in the soil. It can also be controlled using an endophytic fungal parasite of Moniliophthora perniciosa, production of which is not sustainable.
The Portuguese scientists noted that the growth of Moniliophthora perniciosa was reported as being antagonized in vitro by some yeasts, which suggests that they could be used as biological control agents, suppressing the fungus multiplication and containing its spread.
Concurrently, some yeast-based products are used in the protection of fruit from post-harvest fungal spoilage, and the extension of diverse food products shelf-life.
“These successful applications suggest that yeasts can be regarded a serious alternative in the pre-harvest management of Witches’ Broom Disease,” they suggested.
“Yeasts that are generally recognized as safe (GRAS) adds to their appropriateness for field application, not raising major ecological concerns as do the present more aggressive approaches.
“Importantly, mitigating Witches’ Broom Disease in a sustainable manner would have a high socio-economic impact, helping to reduce poverty in the cocoa-producing rural communities.”
In their study, the scientists discuss the importance/advantages and challenges that such a strategy would have for Witches’ Broom Disease containment, and present available information on the molecular and cellular mechanisms underlying fungi antagonism by yeasts.
Correspondence: Professor Cândida Lucas, University of Minho, Braga, Portugal, firstname.lastname@example.org