Modeling Probability of Corn Aflatoxin Using a Drought Index in South Georgia.

Aflatoxin, a mycotoxin produced by Aspergillus flavus or Aspergillus parasitic, is a major food safety concern for corn production in the Southeast US. The likelihood of high temperatures and drought stress during the summer months increased the risk for corn aflatoxin contamination on this region. The main objectives of this study were: 1) to evaluate the statistical relationship between ARID drought index and aflatoxin contamination in South Georgia, and 2) to determine the month(s) within the growing season having the highest association between ARID and aflatoxin contamination. The data used for this study consisted of historic records of aflatoxin contamination from 1977 to 2007 collected from 53 counties in South Georgia  and ARID data computed from 21 weather stations and 3 major soil types covering the same 53 counties. A logistic regression was performed to test the relationship between monthly ARID and corn aflatoxin level exceeding 20 ppb, the restricted level on corn use for animal feed. The results of the study indicated that a logistic model including ARID values from silking to maturity growth stages predicted the likelihood of having aflatoxin contamination with a 70% level of confidence. ARID values of June had the highest contribution to aflatoxin prediction with high ARID values indicating an increase in the chance of aflatoxin contamination level to exceed the 20ppb. Prediction of aflatoxin risk seems promising by monitoring the changes in ARID values throughout corn growing season