#AGTRIVIA answer: Final U.S. #corn plantings have come in above the June estimate 4 times in the last 25 years: 2005, 2007, 2010, 2012. The biggest increase was 886,000 acres (0.9%) in 2012. The downsides tend to be larger, including a 2 mln acre drop in 2013.
No need to wonder about #soybeans.... those plantings have been higher than in June 8 times since 1996, the largest increase being 1.2M acres (1.6%) in 2008. Once again, downsides are larger. Final acres were 3.9M lower than June in 2019. Corn was nearly 2M lower that year, too.
