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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

Whole Kernels

Though the name suggests some inverse relationship between whole kernels and BCFM, the whole kernels test conveys different information than the broken corn portion of the BCFM test. Broken corn is defined solely by the size of the material. Whole kernels, as the name implies, is the percent of fully intact kernels in the sample with no pericarp damage or kernel pieces chipped away.
The exterior integrity of the corn kernel is very important for two key reasons. First, it affects water absorption for alkaline cooking and steeping operations. Kernel nicks or pericarp cracks allow water to enter the kernel faster than intact or whole kernels. Too much water uptake during cooking can result in loss of soluble, non-uniform cooking, expensive shutdown time, or products that do not meet specifications. Some companies pay contracted premiums for corn delivered above a specified level of whole kernels.
Second, intact whole kernels are less susceptible to storage molds and breakage in handling. While hard endosperm lends itself to the preservation of more whole kernels than soft corn, the primary factor in delivering whole kernels is harvesting and handling. This begins with proper combine adjustment followed by the severity of kernel impacts due to conveyors and the number of handlings required from the farm field to the end-user. Each subsequent handling will generate additional breakage. Actual amounts of breakage increase exponentially as moisture decreases, drop heights increase, or a kernel’s velocity at impact increases.4 In addition, harvesting at the higher moisture content (e.g., greater than 25%) will usually lead to soft pericarps and more pericarp damage to corn than when harvesting at lower moisture levels.

Results

  • U.S. Aggregate whole kernels averaged 90.8% in 2019, lower than 2018 (93.0%) and the 5YA (93.3%), but higher than 2017 (89.9%),
  • The 2019 whole kernel standard deviation (4.2%) was higher than in 2018 (3.0%) and the 5YA (3.3%), but lower than in 2017 (4.6%).
  • Whole kernel range in 2019 (25.4 to 99.6%) was much greater than 2018 (66.0 to 98.6%) and 2017 (67.0 to 99.2%).
  • Of the 2019 samples, 68.7% had 90.0% or higher whole kernels, compared to 2018 (85.6%) and 2017 (57.2%). This distribution indicates that 2019 had a lower percentage of whole kernels than the samples in 2018.
  • Whole kernel averages for Gulf, Pacific Northwest and Southern Rail ECAs were 91.5, 88.9 and 91.7%, respectively.