The U.S. Department of Agriculture (USDA) Federal Grain Inspection Service (FGIS) has established numerical grades, definitions, and standards for measurement of many quality attributes. The attributes which determine the numerical grades for corn are test weight, broken corn and foreign material (BCFM), total damage, and heat damage. The table for “U.S. Corn Grades and Grade Requirements” is provided on page 70 of this report.
Summary: Grade Factors and Moisture
Average U.S. Aggregate test weight (58.3 lb/bu or 75.0 kg/hl) was higher than 2015, 2014, and 5YA. It was well above the limit for U.S. No. 1 grade corn.
As in previous years, the average test weight was above the minimum for U.S. No. 1 grade in all ECAs.
Average U.S. Aggregate broken corn and foreign material (BCFM) (0.7%) was less than in 2015, 2014, and 5YA, and well below the maximum for U.S. No. 1 grade. Low BCFM indicates minimal cleaning required for corn delivered to the first handler and should facilitate good aeration during storage.
BCFM levels in almost all (99.2%) of the corn samples were equal to or below the 3% maximum allowed for No. 2 grade.
Average BCFM was the same (0.7%) in all three ECAs.
Average U.S. Aggregate broken corn (0.5%) was slightly lower than previous years and 5YA.
Average U.S. Aggregate foreign material (0.1%) was slightly lower than in previous years and 5YA.
Total damage in the U.S. Aggregate samples averaged 2.6% in 2016, higher than 2015, 2014, and 5YA, but still below the limit for U.S. No. 1 grade (3%). Nearly 72% of the samples contained 3% or less damaged kernels. The standard deviation (1.61%) and range (0 to 23.1%) in total damage were higher than in previous years. With a larger percentage of samples having higher total damage than in previous years, a higher storage risk could occur if corn is not adequately dried, monitored, and properly aerated.
The Pacific Northwest ECA had the lowest total damage in 2016, 2015, 2014, and 5YA, while the Gulf ECA had the highest total damage for 2016, 2015, 2014, and 5YA.
No heat damage was reported on any of the samples, the same as 2015, 2014, and 5YA.
Average U.S. Aggregate moisture content in 2016 (16.1%) was higher than 2015, lower than 2014, and the same as 5YA.
The 2016 average moisture content value for the Southern Rail ECA (15.7%) was lower than the Pacific Northwest (15.9%) and Gulf (16.2%) ECAs’ moisture content values.
The moisture content values’ distributions for 2016 and 2015 imply that more drying may have been required in 2016 than in 2015. In the 2016 crop, only 12.5% of the samples contained 14% or less moisture compared to 19.8% of the samples in 2015.