Modelling Moniliophthora roreri in Costa Rica

A model of the field dynamics of Moniliophthora roreri, its management and economics was developed to evaluate net returns of various management strategies to farmers in Central America. The model is primarily based on the cropping patterns and economics of cocoa production in Costa Rica. With minimal inputs the model can be adapted to simulate the crop phenology and economics in any country, where the disease causes significant economic loss. The model is a time-based deterministic spreadsheet model that simulates the production and management of one hectare of cocoa at weekly intervals over a user-selected two-year period. The model demonstrates the need for frequent stripping of infected pods to prevent sporulating pods accumulating in the field, under a broad range of economic scenarios. The model allows the user to evaluate potential extension advice in terms of user-definable real world variables including: frequency of harvesting and stripping of infected pods; losses of ripe unharvested pods to rodents; ability to identify infected pods; international cocoa prices; farm-gate prices and premiums; and labour costs and requirements. (C) 2002 Published by Elsevier Science Ltd.