Monitoring peanut contamination in Mali (Africa) using AVHRR satellite data and a crop simulation model

Abstract

Peanut (Arachis hypogaea L.) is the main legume crop of Mali, West Africa. It can be contaminated by aflatoxin, a natural toxin that can develop because of drought conditions at pre‐harvest stage or because of temperature‐ and humidity‐related factors that occur during post‐harvest storage. Consumption of aflatoxin‐contaminated peanut can cause liver diseases, such as jaundice, hepatitis or cancer. We present a case study for Mali, identifying weather‐ and satellite‐based variables that could be used to indicate aflatoxin in peanut. Based on this monitoring and predicting, a warning may be issued against eating contaminated peanut to keep the public health from deteriorating. Normalized difference vegetation index (NDVI) composites, derived from advanced very high resolution radiometer (AVHRR) satellite data, were averaged for the reproductive phase of peanut and examined for their relationship with the annual peanut yield, an indicator of drought and aflatoxin. The relationship was found to be moderate (R 2 = 0.56). The commencement and termination dates for the reproductive phase of peanut were determined by using a crop simulation model. Amounts of aflatoxin were measured for peanut samples collected from various locations across Mali and were found to be linked to the NDVI, total precipitation, and maximum temperature averaged over the reproductive phase of peanut.