In most cacao production areas, rainfall totals and temperature maximums range between 1300 and 3000 mm and 30 to 33 °C. These conditions are ideal for WBD development. Generally, there are four major strategies that can be used for disease control of Witches’ Broom. One strategy is phytosanitation, which is the removal and destruction of diseased plant parts. This can only be conducted during dry periods, or one risks spreading the disease further. Other strategies for control are chemical control, genetic resistance and biological control. Genetic resistance is currently being researched. In order to achieve durable resistance to a specific pathogen, extensive knowledge of the genetics of specific host-pathogen interaction is required. Host-pathogen interaction for "M. perniciosa" is not fully known. Some of these strategies can be tedious and expensive, for example, 95% phytosanitation is required to achieve 50% reduction in pod loss. Among the endophytic fungi associated with cacao are many species of "Trichoderma". Several species of "Trichoderma" have been isolated from cacao and is one of the most often used biofungicides. One of the isolates, "T. stromaticum" parasitizes the saprotrophic mycelium and basidiocarps of M. perniciosa, which reduces the formation of basidiocarps by 99% when brooms are in contact with soil and 56% in brooms remaining on trees. It can reduce pod infection by 31%. This biofungicide has shown variable performance due to environmental conditions of high humidity and moisture from rainfall, which is ideal for disease development, but not necessarily ideal for optimizing biocontrol efficacy. "M. perniciosa" infection causes young pods to become deformed (these are called chirimoyas in Spanish), whereas infection of more mature pods will cause necrosis of seeds and render the pod worthless. This largely affects cocoa production in South American countries where their cash crop is cacao beans. In 1989, WBD was introduced to the cocoa producing state of Bahia of Brazil, where output diminished from 380,000 metric tons per year to 90,000 metric tons in the late 1990s. Due to this disease, Bahia, Brazil went from being the 3rd largest exporter of cacao beans to a net importer. Lack of cacao beans could increase the price for importing countries, and also for all cocoa products.