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Corn Export Cargo Quality Report 2018/2019

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. U.S. Corn Export System
  20. U.S. Corn Export Flow
  21. Impact of The Corn Market Channel on Quality
  22. U.S. Government Inspection and Grading
  23. Survey & Statistical Analysis Methods
  24. Survey Design & Sampling
  25. Statistical Analysis
  26. Testing Analysis Methods
  27. Grade Factors
  28. Moisture
  29. Chemical Composition
  30. Physical Factors
  31. Mycotoxins
  32. U.S. Corn Grades & Conversions

Kernel True Density

Kernel true density is calculated as the weight of a 100-kernel sample divided by the volume, or displacement, of those 100 kernels and is reported as grams per cubic centimeter (g/cm3). True density is a relative indicator of kernel hardness, which is useful for alkaline processors and dry millers. True density may be affected by the genetics of the corn hybrid and the growing environment. Corn with higher density is typically less susceptible to breakage in handling than lower density corn, but is also more at risk for the development of stress cracks if high-temperature drying is employed. True densities above 1.30 g/cm3 indicate very hard corn, which is typically desirable for dry milling and alkaline processing. True densities near the 1.275 g/cm3 level and below tend to be softer, but process well for wet milling and feed use.

Results

  • Average U.S. Aggregate kernel true density (1.288 g/cm3) was slightly higher than 2017/2018 (1.287 g/cm3), 2016/2017 (1.285 g/m3) and the 5YA (1.286 g/cm3).
  • Average kernel true density for the 2018/2019 export samples was higher than for the 2018 harvest samples (1.265 g/cm3). The export 5YA true density (1.286 g/cm3) was also higher than the harvest 5YA true density (1.258 g/cm3). Average true densities have been 0.021 to 0.036 g/cm3 higher at export than at harvest over the past eight years.
  • The 2018/2019 export samples had a range of 1.235 to 1.325 g/cm3 (with a standard deviation of 0.011 g/cm3), while the 2018 harvest samples had a wider range (1.167 to 1.374 g/cm3) and a larger standard deviation (0.018 g/cm3).
  • For the 2018/2019 export samples, 85.3% had kernel true densities equal to or above 1.275 g/cm3, compared with 83.0% in 2017/2018 and 80.7% in 2016/2017. This indicates that the distribution of true densities found in the 2018/2019 samples was similar to the distributions from the past three years. Interestingly, average bulk density or test weight also remained constant at 57.4 lb/bu over the past three years and the 5YA.
  • Average kernel true densities for the Gulf, Pacific Northwest and Southern Rail ECAs were 1.293 g/cm3, 1.278 g/cm3 and 1.284 g/cm3, respectively. No consistent pattern in true densities among ECAs has been observed across the years.
  • Average kernel true density for contracts loaded as U.S. No. 2 or better (1.287 g/cm3) was the same as for contracts loaded as U.S. No. 3 or better.