Frosty pod rot (FPR)

Fungal disease, Moniliophthora roreri related to M. perniciosa, has reduced yields dramatically in Latin America. 

Although not the most economically important disease in Latin America where it has appeared, it has rapidly overtaken both black pod and witches’ broom to become the most serious disease with yield losses of up to 90% in the most suitable climates. 

Confined to Ecuador and Colombia, the disease appeared in Costa Rica in the 1970’s and from there has gradually spread north into Central America, south into Panama and the Amazon. 

Still in an invasive phase, FPR has been detected in Jamaica in the Caribbean (2016) and in State of Acre in Brazil in 2021.

The disease, unlike WB, only affects the pods of cocoa and can infect the pods at any stage of development. Symptoms can take several weeks to appear and some pods, especially those infected at a later stage, may show no external symptoms.

In young pods only, slight swellings may appear and pods 1-3 months old show the classic dark lesions followed by the thick mat of cream-coloured spores. 

The beans in pods at all stages of infection will rot and be unusable.
 

• In Costa Rica [1], the oxathiin fungicide flutolanil, which had previously been shown to be efficaceous against WBD in Trinidad [2] and copper-based fungicides provided the most effective chemical control of FPR: but the benefit / cost ratio was limited (approx. 1.7 after 8-10 sprays at 2003 prices). A review of fungicide efficacy against the Moniliophthora diseases in Ecuador [3] suggested that asoxystrobin gave at least as good control as the chemical standard (clorothalonil plus copper oxide).
• Classical biocontrol has also been explored using various fungal endophyte. In Costa Rica, Trichoderma ovalisporum (oil formulation) in field trials was found to be as effective as flutolanil and copper hydroxide fungicides in managing FPR [4].
• To effectively manage FPR, cultural practices remain the best option. Rehabilitate cocoa to reduced tree height to make phytosanitary pruning more effective, maintenance pruning to reduce humidity in the canopy.
• Weekly phytosanitation to remove diseased pods, preferably before they start to sporulate – it is essential that farmers are taught to recognise the earliest symptoms. The cut pods should be covered with leaf litter or piled up and sprinkled with lime or sprayed with 15% urea and covered with plantain leaves.
• Many producers do not effectively manage FPR using cultural methods as labour is too costly.