The condition of the 2021 Indiana corn crop, as estimated weekly by USDA-NASS, ranks among the top 6 most recent growing seasons dating back to 2004. The accompanying graph illustrates the percentage of the state’s corn crop rated as ‘good’ to ‘excellent’ through Sunday, July 25. Also depicted are the five most recent years with similarly ‘good’ to ‘excellent’ crop conditions.
Departures from trend grain yield in those five years ranged from +2.6% (2016) to +13.9% (2014). The trend grain yield (aka expected yield for an ‘average’ year) for Indiana corn in 2021 would be 177.3 bushels per acre (based on simple linear regression of grain yield versus year since 1956, R-square = 0.81). If crop condition remains at its current level for the remainder of the growing season, my analysis of historical relationships between grain yield and season-long crop condition ratings from 1986-2020 suggests that this year’s corn grain yield potential might be +7% to +8% above trend yield (approximately 190 bushels per acre).
Of course, the range in grain yield departures shown by the 5 recent years with similar crop conditions (accompanying graph) reinforces the fact that such analyses of historical data have their margins of error. Nevertheless, the 2021 Indiana corn crop is on track for excellent grain yields at harvest this fall.
Reference:
USDA-NASS. 2021. Crop Progress. USDA Economics, Statistics and Market Information System. https://usda.library.cornell.edu/concern/publications/8336h188j [URL accessed 7/28/2021].
Figure 1. Seasonal Indiana Corn Crop Condition Ratings for Select Years.
Adapted from USDA-NASS weekly crop progress data.
