Peanut (Arachis hypogoea) is an important crop in Mali, West Africa. However, one of the main problems related to peanut production and
commercialization is the detection of high levels of aflatoxin B1 in peanut-derived products for consumption. The objectives of this study were 1) to
determine the rate of progress of Aspergillus flavus and aflatoxin B1 in granaries located in 26 villages and also in the granaries located in the
corresponding 26 markets in Mali and 2) to correlate the progress of the A. flavus and aflatoxin B1 with environmental variables outside the peanut
granaries. The results showed that peanuts stored and consumed in rural areas are highly contaminated by A. flavus and aflatoxin B1, with average
rates of aflatoxin B1 significantly above the accepted international standards especially between the months of June and December. There was a
moderate relationship (r2 = 0.58) between the aflatoxin B1 levels for two granary types, located at the villages and the corresponding granaries in the
markets. The analysis of the aflatoxin B1 levels in the villages and its relation with the weather conditions outside the granaries revealed that for one
village (Tiele), high relative air humidity was a contributing factor in the development of A. flavus and levels of the aflatoxin B1 in the granary. The
results indicated that maximum aflatoxin B1 production occurs in presence of warm temperatures and relative humidity above 80%
