Pollination is the most critical phase of development for determining corn yields. Corn pollination (or silking) has already begun across the Delta and the Southeast and will eventually expand into the Midwest in the coming weeks.
Unsurprisingly, corn pollination is expected to occur much later than normal this year due to the record planting delays this spring. Nationally, the 50% corn pollination date is expected to occur on July 27, 10 days later than the 5 year average and 15 days later than last year. The most significant delays are expected across the eastern Midwest, where pollination is expected to occur nearly 3 weeks later than the 5 year average.
The delayed development of the corn crop would actually push the pollination phase into a climatologically slightly cooler time of the summer. However, the delayed development of the corn crop in the eastern Midwest will push pollination into a climatologically drier time of the summer, with normal precipitation during the expected pollination window (early August) in Illinois, Indiana, and Ohio averaging 15-30% less than during the 5 year average pollination window (mid July).
“Late pollination increases the potential for stress on the corn crop in these areas,” said Kyle Tapley, Maxar’s Weather Desk Meteorologist.
The weather forecast through the end of June across the Midwest has temperatures spiking in the low to middle 90s especially for the central to western corn belt. The recent floodwaters have receded a bit across the southern Midwest, however precipitation will be plentiful across the largest corn producing areas of the region, including Iowa.
“Portions of northern Illinois to southern Minnesota could observe rainfall amounts of 1 to 3 inches over the next 5 days,” according to Tapley. The combination of late pollination and the upcoming weather conditions does not bode well for end-of-season corn yields. As a result, the yields will more than likely be significantly lower in parts of the Midwest versus the 2018 growing season.