C. Harvest Conditions (September – October +)
Harvest moved along slowly accompanied by differing crop conditions
At the end of the growing season, dry down of the grain is dependent upon sunshine, temperature, humidity levels, and soil dryness. Corn can most effectively dry down with the least adverse impact on quality with sunny, warm days with low humidity. Another weather concern at the end of the growing season is freezing temperatures. Early freezing before the grain can sufficiently dry down may lead to lower test weight, and the wetter grain may be susceptible to greater breakage than drier grain during harvest.
Typically, 80% of the U.S. corn is harvested by the end of October. However, harvest in 2013 was delayed by two to three weeks on average. The corn reached maturity more slowly than normal because of the late planting and cool summer, therefore attaining the dry down stage later than average. Fields that were drought stressed had non-uniform maturation, with adjacent areas of mature and green plants. In addition, areas across all twelve states experienced either cooler than normal temperatures, higher than average precipitation in the form of either snow or rain, or a combination of both. These weather conditions delayed harvest further and/or prompted producers to harvest fields with areas of high-moisture grain trying to minimize fungus and mycotoxin development.
In total, the 2013 weather of floods, droughts, a late summer heat wave, and early snowstorms in the Dakotas combined to decrease harvested acreage by 8% from the originally planted area.
The summer growing conditions and the overall cool, wet harvest weather were not conducive to aflatoxin development in the majority of the growing area of the states surveyed for this Harvest Report 2013/14. On the other hand, warm and wet weather during flowering and delayed maturation (resulting in wet grain) and harvest in some areas may have led to some DON development.