Managing Global Resources for a Secure Future

Corn aflatoxin contamination is a chronic issue in Southern US. Agronomic practices (i.e., planting dates and population densities) may have an influence on crop yields and kernel toxin accumulation. In principle, alleviating crop stress during critical growth stages is expected to improve yields and decrease contamination levels. The objectives of the study were to: 1) assess planting dates and population densities effect on pre-harvest contamination in rainfed corn, 2) determine which weather variables and their temporal pattern influence contamination, and 3) identify the relative weight of significant weather factors on infection and contamination in corn for South and Central AL. Field experiments were run in Fairhope (5 years) and Prattville (2 years), AL. In the split–split plot design, inoculation, planting dates, and plant densities were assigned to main plots, sub-plots, and sub-subplots. Late planting dates had consistently and sometimes significantly lower aflatoxin contamination compared to early sowing dates; whereas, plant densities were not significant. A significant negative linear relationship was found between aflatoxin and yield for 2011 in Fairhope. Minimum air temperature and rainfall variables were associated with aflatoxin contamination. Temporal variation for aflatoxin contamination in AL was detected. Rainfall and minimum temperature influence, and the effect direction on contamination, changes for the timespan around silking tested herein.