Application of a model to assess aflatoxin risk in peanuts

Abstract

SU MMARYWhen exposed to hot (22-35 xC) and dry climatic conditions in the field during the final 4-6 weeks of pod filling, peanuts (Arachis hypogaea L.) can accumulate highly carcinogenic and immunosuppressing aflatoxins. Forecasting of the risk posed by these conditions can assist in minimizing preharvest contamination. A model was therefore developed as part of the Agricultural Production Systems Simulator (APSIM) peanut module, which calculated an aflatoxin risk index (ARI) using four temperature response functions when fractional available soil water was <0 . 20 and the crop was in the last 0 . 40 of the pod-filling phase. ARI explained 0 . 95 (Pf0 . 05) of the variation in aflatoxin contamination, which varied from 0 to c. 800 mg/kg in 17 large-scale sowings in tropical and four sowings in sub-tropical environments carried out in Australia between 13 November and 16 December 2007. ARI also explained 0 . 96 (Pf0 . 01) of the variation in the proportion of aflatoxincontaminated loads (>15 mg/kg) of peanuts in the Kingaroy region of Australia during the period between the 1998/99 and 2007/08 seasons. Simulation of ARI using historical climatic data from 1890 to 2007 indicated a three-fold increase in its value since 1980 compared to the entire previous period. The increase was associated with increases in ambient temperature and decreases in rainfall. To facilitate routine monitoring of aflatoxin risk by growers in near real time, a web interface of the model was also developed. The ARI predicted using this interface for eight growers correlated significantly with the level of contamination in crops (r=0 . 95, Pf0 . 01). These results suggest that ARI simulated by the model is a reliable indicator of aflatoxin contamination that can be used in aflatoxin research as well as a decision-support tool to monitor pre-harvest aflatoxin risk in peanuts.

Modelling climate change impacts on mycotoxin contamination

“…Some attempts regarded also Fusaria (Van Asselt et al, 2012) and A. flavus Chauhan et al, 2015) in maize, while only few studies regard other toxins/crops, e.g. aflatoxins in peanuts (Chauhan et al, 2010) and OTA in grapes (Battilani and Camardo Leggieri, 2015a).…”

Risk Assessment and Prediction of Aflatoxin in Agro-Products

“…Due to the annual and climatic variation of AFB 1 contamination level, it is necessary to build a prediction model by developing a continuous and effective AFB 1 monitoring program for pre-harvest peanuts during its growing season. Up to now, there had been some progress on model building in Australia and USA [28,29].…”

“…Until now, a lot of researches indicated that key environmental factors including temperature, humidity and precipitation significantly influenced fungus growth, infection as well as aflatoxin production [30][31][32]. And some efforts have been devoted to developing models to predict aflatoxin contamination in peanuts and maize with climatic data used as the main or only input, such as the Agricultural Production Systems Simulator (APSIM) and the CSM-CROPGRO-Peanut model [29,33]. However, few models were actually applied to the field to predict the future aflatoxin risk or just a small region for validation and demonstration.…”

Temperature and Moisture Conditions That Affect Aflatoxin Contamination of Peanuts

“…Cole et al (1985) noted that geocarposphere temperatures averaging 26.3 to 29.6 C were most conducive to aflatoxin accumulation in peanuts, while temperatures above 31.3 C appeared suppressive. These studies and others provided the information that Chauhan et al (2010) built into a simulation model that calculates the risk of aflatoxin contamination in peanuts. While this simulation has been shown to be reliable, its use may be limited due its complexity and the need for multiple environmental variable inputs.…”