Chocolate lowland climate in the narrow band of latitudes where cacao is grown (20 degrees north and south of the equator), the commercial company Mars, Incorporated and the University of California, Berkeley are conducting genomic research in 2017–18 to improve the survivability of cacao plants in hot climates. Chocolate is made from cocoa beans, the dried and fermented seeds of the cacao tree ("Theobroma cacao"), a small, 4–8 m tall (15–26 ft tall) evergreen tree native to the deep tropical region of the Americas. Recent genetic studies suggest the most common genotype of the plant originated in the Amazon basin and
Cacao necrosis virus an effective cultural control method. This does not prevent new spread although spread is greatly reduced due to the limited dispersal of the nematode vector and subsequent monocyclic cycle of disease No resistant strains have been produced, though a resistant cacao tree may be the best possible management option looking forward. A similar transgenic approach taken to combat papaya ringspot virus could work for cacao based on the type of vector transmission. Seed transmission is estimated to be up to 24% depending on the plant species so cacao plantations should be planted from clean seed stock. This disease is currently