How did the extreme heat during July 2012 affect yields?
There was a strong correlation between planting date, average temperature and yields. Fields planted in the first planting window from April 11 to 14, pollinated at the end of the first week of July with temperatures averaging 102 degrees…not a good combination! The next planting window, April 20 through 26, pollinated at the end of the 2nd week of July and averaged 91 degrees. Rains on the 12th and 13th of July helped the fields planted late on the 25th and 26th of May, even though these seedbeds faced stiff challenges with cold rains on April 27th. The best window was May 11 through 15, which hit the only substantial rain in July, and averaged temps in the low 90′s.
The most amazing thing to me is how good yields were when we actually received rain at pollination. Those areas recorded best ever yields because of an extra two inches of rain in late June and early July. The tremendous heat during July was shrugged off, and the corn produced!