I. Harvest Quality Highlights
The representative samples tested for the 2018/2019 Corn Harvest Quality Report indicate the overall quality of the 2018 corn crop was better than the average of the previous five crop years (5YA1) on many attributes. Approximately 93.9% of the samples met the standards for U.S. No. 2 grade.
The 2018 U.S. corn crop is entering the market channel with lower average total damage, broken corn and foreign material (BCFM), moisture and stress cracks; and higher average test weight, oil concentration, 100-k weight and true density relative to the 5YA.
Grade Factors and Moisture
- Average test weight of 58.4 lb/bu (75.1 kg/hl), with 90.3% above the limit for No. 1 grade, and 98.2% above the limit for No. 2 grade. Similar to 2017 and higher than the 5YA, this test weight indicates good kernel filling and maturation.
- Low levels of BCFM (0.7%), slightly lower than 2017 and the 5YA. In 2018, 98.1% of the samples were below the limit for No. 2 grade, which indicates little cleaning should be required. This is similar to 2017 and 2016, when 98% and 99% of samples, respectively, were below the BCFM limit for No. 2 grade.
- Average total damage of 1.5% was higher than 2017 but lower than 2016 and the 5YA, and 97.1% of the samples were below the total damage limit for No. 2 grade.
- There was no observed heat damage in any samples received.
- Lower elevator moisture content (16.0%) than 2017 and the 5YA, but similar to 2016 which was also a good field drying year. The distribution shows 24.7% of the samples were above 17% moisture content as compared to 36% and 29% in 2017 and 2016, respectively. This distribution indicates fewer samples required artificial drying in 2018 than in 2017.
- Protein concentration (8.5% dry basis) was slightly lower than in 2017 and 2016 but similar to the 5YA.
- Higher starch concentration (72.5% dry basis) than 2017, same as 2016 but lower than the 5YA.
- Average oil concentration of (4.0% dry basis), lower than 2017, same as 2016 and higher than the 5YA.
- The 2018 crop had a low percentage of stress cracks (5%); same as 2017, higher than 2016, but lower than the 5YA, with 89.0% of the samples having less than 10% stress cracks.
- Average stress crack index (11.5); lower than 2017 and the 5YA, but higher than 2016 which was also a good field drying year. Susceptibility to breakage should remain relatively low.
- Lower 100-k weight (35.07 g) than 2017, but similar to 2016 and higher than the 5YA, signifying generally smaller kernels than 2017 but similar to previous years.
- Average kernel volume of 0.28 cm3; lower than 2017, but similar to 2016 and the 5YA.
- Average true density of 1.265 g/cm3; higher than 2017, 2016 and the 5YA.
- Higher average whole kernels (93.0%) than 2017, lower than 2016 and similar the 5YA.
- Average horneous endosperm of 81%; similar to 2017 and the 5YA, but higher than 2016. This indicates kernel hardness similar to last year and the 5YA.
- All but one sample, or 99.5%, of the 2018 corn samples, tested below the U.S. Food and Drug Administration (FDA) action level for aflatoxin of 20.0 ppb.
- In 2018, 100% of the corn samples tested below the 5.0 ppm FDA advisory level for deoxynivalenol (DON or vomitoxin), same as in 2017 and 2016. In addition, 74.6% of the samples tested below the U.S. Department of Agriculture (USDA) Federal Grain Inspection Service (FGIS) “Lower Conformance Level”, a lower proportion than in 2017. This decrease may be attributed to weather conditions that were more conducive to DON development in 2018 than in 2017.