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Corn Harvest Quality Report 2019/2020

Contents

  1. Export Cargo Quality Highlights
  2. Introduction
  3. Grade Factors
  4. Quality Test Results
  5. Moisture
  6. Chemical Composition
  7. Physical Factors
  8. Stress Cracks
  9. 100- Kernel Weight
  10. Kernel Volume
  11. Kernel True Density
  12. Whole Kernels
  13. Horneous (Hard) Endosperm
  14. Mycotoxins
  15. Assessing the Presence of Aflatoxins and Deoxynivalenol (DON)
  16. Background: Mycotoxins General
  17. Background: Aflatoxins
  18. Background: Deoxynivalenol (DON) or Vomitoxin
  19. Background: Fumonisin
  20. U.S. Corn Export System
  21. Planting and Early Growth Conditions
  22. Pollination and Grain-fill Conditions
  23. Harvest Conditions
  24. Comparison of 2019 to 2018, 2017 and the 5YA
  25. U.S. Corn Production, Usage & Outlook
  26. U.S. Corn Use and Ending Stocks
  27. Survey Design and Sampling
  28. Statistical Analysis
  29. Grade Factors
  30. Physical Factors
  31. Mycotoxins
  32. U.S. Corn Grades & Conversions

Export Cargo Quality Highlights

The overall quality of the 2019 crop was impacted by late planting, delayed maturation and kernel filling and late harvest conditions as reflected in high corn moisture and low density. The high moisture led to the need for more heated-air drying, which increases the potential for stress cracking. The average aggregate quality of the representative samples tested for the U.S. Grains Council 2019/2020 Corn Harvest Quality Report (2019/2020 Harvest Report) was better than the grade factor requirements for U.S. No. 1 grade corn, indicating an abundant amount of good quality corn is entering the marketing channel from the 2019 U.S. crop. The report also showed that 54.6% of the samples met the grade factor requirements for U.S. No. 1 grade, and 81.7% met the grade factor requirements for U.S. No. 2 corn. Relative to each quality factor’s average of the previous five crops (5YA1), the 2019 U.S. corn crop is entering the marketing channel with lower average test weight, whole kernels and protein concentration; and higher broken corn and foreign material (BCFM), moisture, total damage, stress cracks and oil concentration. The following points highlight the key harvest results from the 2019 crop.

Grade Factors and Moisture

  • Lower test weight of 57.3 pounds per bushel (lb/bu) (73.8 kilograms per hectoliter (kg/hl)) than 2018 and the 5YA. While 89.9% of the samples were above the minimum requirement for U.S. No. 2 grade, this proportion is lower than in 2018 and 2017, when 98.2% and 99.9% of samples, respectively, were at or above the minimum requirement for U.S. No. 2 grade.
  • Higher average BCFM (1.0%) than 2018 and the 5YA. While the average is higher than in previous crops, 96.8% of the samples were below the limit for U.S. No. 2 grade.
  • Higher average total damage (2.7%) than 2018 and the 5YA. While the average is higher than in previous crops, 91.5% of the samples were below the limit for U.S. No. 2 grade. The variability in total damage (standard deviation = 2.43%) in 2019 was also much higher than in previous years.
  • There was no observed heat damage in any samples received.
  • Higher average moisture content (17.5%) and variability (standard deviation = 2.35%) than 2018 and the 5YA. This is the highest average moisture observed in the nine-year history of the report and may be the result of the historically late planting of the 2019 crop. The distribution shows that 45.7% of the samples were above 17% moisture content as compared to 24.7% and 36.2% in 2018 and 2017, respectively. This distribution indicates more samples required artificial drying in 2019 than in the two previous years.

Chemical Composition

  • Protein concentration (8.3% dry basis) was lower than in 2018 and the 5YA.
  • Starch concentration (72.3% dry basis) was slightly lower than in 2018 and the 5YA.
  • The average oil concentration (4.1% dry basis) was higher than in 2018 and the 5YA.

Physical Factors

    • The 2019 crop had a higher percentage of stress cracks (9%) than 2018 and the 5YA, with 10.8% of the samples having more than 20% stress cracks, indicating greater susceptibility to breakage than in 2018 and 2017. The higher percentage of stress cracks in 2019 is likely the result of the crop’s delayed maturation, wet harvest conditions and additional artificial drying to reduce relatively high harvest moisture to safe levels for storage.
    • 100-kernel weight (34.60 grams) was lower than in 2018 and the 5YA, indicating smaller kernels than the previous two years.
    • The average kernel volume (0.28 cubic centimeters (cm3)) was smaller than 2017, but the same as 2018 and the 5YA.
    • The average true density (1.247 grams per cubic centimeter (g/cm3)) from the 2019 crop was lower than in 2018 and the 5YA. This is likely due to late planting, delayed maturation and kernel filling and late harvest conditions in 2019.
    • The whole kernel average (90.8%) was lower than in 2018 and the 5YA.
    • Average horneous (hard) endosperm of 81% was the same as in 2018 and 2017.

    Mycotoxins

      • All but one sample, or 99.4%, of the 2019 samples, tested below the U.S. Food and Drug Administration (FDA) action level for aflatoxin of 20.0 parts per billion (ppb); and 97.8% of the samples tested below 5.0 ppb.
      • In 2019, 100% of the samples tested below the 5.0 parts per million (ppm) FDA advisory level for deoxynivalenol (DON), the same as in 2018 and 2017. Also, 59.9% of the samples tested below the U.S. Department of Agriculture (USDA) Federal Grain Inspection Service (FGIS) “Lower Conformance Limit,” a higher proportion than in 2018 and 2017. This increase may be attributed to weather conditions that were more conducive to DON development in 2019 than in 2018 and 2017.
      • One hundred fifty-six (156) of the 182 samples tested for fumonisin, or 85.7%, tested below the FDA’s strictest guidance level for fumonisin of 5.0 ppm.