Here are a few ways in which climate change can contribute to increased aflatoxin risk in US corn:
1. Higher Temperatures: Aspergillus flavus and Aspergillus parasiticus thrive at temperatures between 25-35°C (77-95°F). Climate change is expected to increase the frequency of heat waves, resulting in longer periods of time when corn is exposed to these optimal temperatures for aflatoxin production.
2. Increased Humidity: High humidity levels promote fungal growth and aflatoxin production. Climate change is projected to lead to increased humidity in many corn-growing regions, particularly in the Midwest and Southeast.
3. Drought Stress: Drought conditions can make corn more susceptible to aflatoxin contamination. Drought can cause plants to produce smaller ears with fewer kernels, reducing the overall yield. This stress response can lead to increased levels of aflatoxin in the remaining kernels.
4. Altered Planting and Harvesting Seasons: Changes in temperature and precipitation patterns may affect the timing of corn planting and harvesting. Earlier planting dates and delayed harvests due to extreme weather events can increase the risk of aflatoxin contamination, as corn may spend more time in the field under favorable conditions for fungal growth.
5. Geographic Range Expansion: Climate change may also expand the geographic range of aflatoxin-producing fungi, allowing them to flourish in areas previously considered less conducive to their growth. This could lead to new regions becoming vulnerable to aflatoxin contamination.
To mitigate the risk of aflatoxin contamination in corn under a changing climate, farmers may need to adopt improved agricultural practices, such as using resistant corn varieties, crop rotation, irrigation management, and post-harvest drying and storage techniques. Monitoring weather patterns and implementing timely interventions can also help reduce the impact of climate change on aflatoxin risk in corn.
