Dan Quinn, Ph.D.
Extension Corn Specialist
Purdue University
Email: djquinn@purdue.edu
Twitter: @PurdueCorn
The USDA recently released their first monthly crop report on August 12, which includes crop production data for the U.S., including estimates for 2021 area harvested, yield, and total production. The link to this report can be found here: https://usda.library.cornell.edu/concern/publications/tm70mv177?locale=en
The USDA currently estimates the Indiana corn crop yield in 2021 at 194 bushels per acre which would be 5 bushels per acre greater than the state record yield average produced in 2018 (189 bushels per acre) and a 7 bushel per acre increase from the 2020 state yield average (187 bushels per acre). The predicted value of 194 bushels per acre is also the highest yield average predicted for Indiana from an August USDA crop report. Furthermore, this predicted yield average value also ranks Indiana second in the corn belt in predicted yield average behind Illinois which has a predicted yield average of 214 bushels per acre.
The value of 194 bushels per acre is currently 8-9% above yield trend (Figure 1) and is likely driven by timely planting, adequate soil moisture, and high crop condition ratings throughout the 2021 growing season. The most recent crop condition rating placed Indiana Corn at 74% good to excellent on August 9th (https://www.nass.usda.gov/Statistics_by_State/Indiana/Publications/Crop_Progress_&_Condition/index.php), which is currently the highest mid-August crop condition rating since 2013, which measured 77% good to excellent on August 11, 2013.
Figure 1: Current 2021 USDA Crop Report predicted yield average in comparison to Historic Indiana State Corn Yield Average (1866 – 2020).
The question I have been asked often since the report was released is do I believe the predicted yield average of 194 bushels per acre? Well, looking at historic yield trends and also pulling state yield averages from years with similar mid-August crop condition ratings which includes: 2018 (74% good to excellent), 2014 (72%), 2006 (72%), 2001 (73%), and 1993 (74%), I predicted the yield average prediction would be around 6.5 to 7.5% above trend or around 191 to 192 bushels per acre. Each previous year with similar mid-August crop condition ratings produced above trend final yield averages which ranged from 3 to 12% above trend. Therefore, I think when you look at the historic data and the overall health of the corn crop this year across the state, I believe the predicted yield average by the USDA is in the range of what we believed it would be.
However, there is still time left in the current growing season, and still plenty of yield left to be determined. For example, from growth stage R5 (dent) to growth stage R6 (maturity or black layer), corn still has approximately 50% of its kernel weight left to be accumulated, which can be influenced by environmental and crop conditions. Furthermore, significant disease progression from pathogens such as tar spot and southern rust, significant saturated conditions and ponding from June and July rainfall in certain areas of the state, and decreased sunlight and solar radiation due to cloudy and hazy conditions during pollination and early grain fill have me cautiously optimistic about the potential for state record yield averages in the state this year. The state of Indiana is on pace for a strong corn crop in 2021, yet time will only tell once the combines start rolling this fall.
