guest post by David Archibald
The USDA continues to predict a big corn crop of 13.9 billion bushels at an average yield of 169.5 bushels per acre. AccuWeather’s estimate is 6% lower at 13.07 billion bushels. What happens from here is largely dependent upon when the first killing frost hits. As the Indiana crop progress report released on August 19 notes, “Growers continued to hope for a late killing frost.” They are hoping because there is a lot of doubt whether or not the crop will have matured by then.
Figure 1: Indiana Corn Crop Condition
As Figure 1 shows, the 2019 crop is the worst for the last five years with only about 35% rate as good or excellent. Note that the 2019 line started in mid-June because of delayed planting due to cold and wet conditions.
Figure 2: Indiana Corn Crop Progress
Figure 2 shows that crop progress is about two and a half weeks behind the 2014-2018 average. From here the crop won’t be 50% mature until the second week of October.
Figure 3: Northwest Indiana Average Weekly Growing Degree Days
The growing season is now rapidly running out of time and temperature.
Figure 4: Calculated GDU deficit to October 15
Atmospheric scientist Eric Snodgrass has provided a map of how that is most likely to play out. For 95 day corn requiring 2280 GDUs to black layer (the abscission layer when the corn kernel reaches maturity), the map in Figure 4 shows the amount of shortfall assuming corn was planted on June 1 and the rest of the season is average.
A large swathe across the top of the Corn Belt is predicted not to make it. What does that remind us of? It reminds us of the Medieval Warm Period to Little Ice Age transition in the Corn Belt as shown in Figure 5 following:
Figure 5: The northern limit of Indian corn growing
Archeological evidence shows that the northern limit of Indian corn growing was forced up to 300 km south in the transition from the Medieval Warm Period to the Little Ice Age. Solar activity has fallen from its 8,000 year peak in the Modern Warm Period from 1933 to 2006 and is now back at levels of the late Little Ice Age. We can expect to repeat the experience of the Indians some 700 years ago.
David Archibald is the author of American Gripen: The Solution to the F-35 Nightmare.