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Corn Export Cargo Quality Report 2015/2016

Contents

  1. Export Cargo Quality Highlights
  2. Introduction
  3. Quality Test Results
  4. Moisture
  5. Chemical Composition
  6. Physical Factors
  7. Mycotoxins
  8. U.S. Corn Export System
  9. U.S. Corn Export Flow
  10. Impact of the Corn Market Channel on Quality
  11. U.S. Government Inspection and Grading
  12. Survey and Statistical Analysis Methods
  13. Survey Design and Sampling
  14. Statistical Analysis
  15. Testing Analysis Methods
  16. Corn Grading Factors
  17. Moisture
  18. Chemical Composition
  19. Physical Factors
  20. Mycotoxin Testing
  21. U.S. Corn Grades and Conversions
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III. QUALITY TEST RESULTS

A. Grade Factors

The USDA’s Federal Grain Inspection Service (FGIS) has established numerical grades, definitions and standards for grains. 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 51 of this report.

SUMMARY: GRADE FACTORS AND MOISTURE

  • Average U.S. Aggregate test weight (57.3 lb/bu or 73.7 kg/hl) was lower than 2014/2015 (57.5 lb/bu) and 4YA (57.7 lb/bu), but well above the limit for U.S. No. 1 grade corn (56 lb/bu).
  • Average U.S. Aggregate BCFM (3.0%) was the same as in 2014/2015. However, approximately 57.3% of the export samples contained levels at or below the maximum allowed for U.S. No. 2 grade (3%).
  • Average U.S. Aggregate total damage (1.9%) and heat damage (0.0%) were well below the limits for U.S. No. 1 grade.
  • Test weight, total damage, and heat damage averages for contracts loaded as U.S. No. 2 o/b and contracts loaded as U.S. No. 3 o/b were better than U.S. No. 1 grade.
  • BCFM averages were at or below the grade limits of the U.S. No. 2 o/b and U.S. No. 3 o/b contracts.
  • Average U.S. Aggregate moisture content (14.4%) was lower than 2014/2015 (14.5%), but same as 4YA (14.4%).
  • Only 26.0% of the 2015/2016 export samples had moistures above 14.5%, compared to 40% in 2014/2015.

1. Test Weight

Test weight (weight per volume) is a measure of bulk density and is often used as a general indicator of overall quality and as a gauge of endosperm hardness to alkaline cookers and dry millers. It reflects kernel hardness and kernel maturity. Test weight is initially impacted by genetic differences in the structure of the kernel. However, it is also affected by moisture content, method of drying, physical damage to the kernel (broken kernels and scuffed surfaces), foreign material in the sample, kernel size, stress during the growing season, and microbiological damage. High test weight at the export point generally indicates high quality, high percent of horneous (or hard) endosperm, and sound, clean corn.

RESULTS

  • Average U.S. Aggregate test weight (57.3 lb/bu or 73.7 kg/hl) was lower than 2014/2015 (57.5 lb/bu) and 4YA (57.7 lb/bu), but the same as 2013/2014 (57.3 lb/bu). The average U.S. Aggregate test weight was above the limit for U.S. No. 1 grade (56.0 lb/bu).
  • The 2015/2016 export samples had less variation than the 2014/2015 export samples, as indicated by the lower standard deviation (0.77%) compared to 2014/2015 (0.90%). However, the 2015/2016 variation was close to 4YA (0.79%). The range in values was also less than 2014/2015 and 2013/2014.
  • Test weight for 95.9% of the samples was at or above the minimum for U.S. No. 1 grade (56 lb/bu), and 100.0% of the samples were at or above the limit for U.S. No. 2 grade (54 lb/bu).
  • Test weight at export was lower than at 2015 harvest (58.2 lb/bu or 74.9 kg/hl). Average test weight at export has been consistently lower than at harvest, with 4YA export average (57.7 lb/bu or 74.2 kg/hl) lower than 4YA harvest average (58.1 lb/bu or 74.8 kg/hl).
  • The 2015/2016 export samples’ variability (standard deviation of 0.77%) was less than the 2015 harvest samples (1.08%). As corn is commingled moving through the market channel, test weight changes and becomes more uniform, with a lower standard deviation and a smaller range between maximum and minimum values than at harvest. At export, 4YA standard deviation was 0.79% compared to 4YA of 1.39% at harvest.
  • Test weight was higher in samples from the Gulf (57.5 lb/bu) and Southern Rail (57.2 lb/bu) ECAs in comparison to samples from the Pacific Northwest ECA (56.8 lb/bu).
  • Average test weight of corn for contracts loaded as U.S. No. 2 o/b (57.3 lb/bu) was slightly higher than for those contracts loaded as U.S. No. 3 o/b (57.2 lb/bu). Averages for both contracts were above the limit for U.S. No. 1.

2. Broken Corn and Foreign Material (BCFM)

Broken corn and foreign material (BCFM) is an indicator of the amount of clean, sound corn available for feeding and processing. As corn moves from farm deliveries through the market channel, each impact on the grain during handling and transporting increases the amount of broken corn. As a result, the average BCFM in most shipments of corn will be higher at the export point than in deliveries to the local elevator.

Broken corn (BC) is defined as corn and any other material (such as weed seeds) small enough to pass through a 12/64th inch round-hole sieve, but too large to pass through a 6/64th inch round-hole sieve.

Foreign material (FM) is defined as any non-corn pieces too large to pass through a 12/64th inch round-hole sieve, as well as all fine material small enough to pass through a 6/64th inch round-hole sieve.

The diagram to the right illustrates the measurement of broken corn and foreign material for the U.S. corn grades.

RESULTS

  • Average U.S. Aggregate BCFM in export samples (3.0%) was at the maximum for U.S. No. 2 grade. It was the same as 2014/2015 (3.0%), but slightly higher than 2013/2014 (2.9%) and 4YA (2.9%).
  • The variability of the 2015/2016 export samples (with a standard deviation of 0.71%) was higher than 2014/2015 (0.65%) and 4YA (0.66%).
  • BCFM in the 2015/2016 export samples was distributed with 57.3% of the samples at or below the limit for U.S. No. 2 grade (3%), and 90.6% at or below the limit for U.S. No. 3 grade (4%).
  • Average U.S. Aggregate BCFM at export (3.0%) was higher than at harvest (0.8%). This increase is consistent with previous years (4YA harvest average was 0.9%, compared to 4YA export average of 2.9%) and is likely a result of drying and increased breakage occurring with additional handling impacts.
  • Southern Rail ECA average BCFM (2.3%) was lower than either the Gulf (2.9%) or Pacific Northwest (3.8%) ECAs’ average BCFM.
  • Average BCFM for contracts loaded as U.S. No. 2 o/b was 2.9%, compared to the average BCFM of 3.4% for contracts loaded as U.S. No. 3 o/b. Corn arriving at the export point is normally commingled from many origins to meet the limits for the contracted grade.

3. Total Damage

Total damage is the percentage of kernels and pieces of kernels that are visually damaged in some way, including damage from heat, frost, insects, sprouting, disease, weather, ground, germ and mold. Most of these types of damage result in some sort of discoloration or change in kernel texture. Damage does not include broken pieces of grain that are otherwise normal in appearance. Mold damage and the associated potential for mycotoxins is the damage factor of greatest concern. Mold damage is usually associated with higher moisture content and high temperature conditions during growing or storage.

Corn with low levels of total damage is more likely to arrive at destination in good condition than corn with high levels of total damage. High levels of total damage have the potential to increase moisture and microbiological activity during transport.

RESULTS

  • Average U.S. Aggregate total damage (1.9%) was lower than 2014/2015 (2.3%), same as 4YA (1.9%), and well below the 3.0% limit for U.S. No. 1 grade.
  • Variability, as indicated by the standard deviation in the 2015/2016 samples (0.88%), was slightly lower than 2014/2015 (0.92%) and 4YA (1.04%). The 2015/2016 sample range (0.0 to 7.2%) was similar to 2014/2015 and 2013/2014 (both 0.0 to 7.0%).
  • Of the export samples, 86.0% had 3.0% or less damaged kernels, meeting the requirement for U.S. No. 1 grade. In addition, 99.0% were below the limit for U.S. No. 2 grade (5.0%).
  • The average level of total damage in the market channel increased, from 1.4% at harvest to 1.9% at export. Over the years, there has been consistently higher total damage in samples at export than at harvest (4YA export average of 1.9% and 4YA harvest average of 1.1%). This increase, still leaves the corn well within the grade limits despite the additional time in transport and storage prior to export, and indicates good management practices in the market channel.
  • The Pacific Northwest ECA had lower total damage (0.4%) compared to the Gulf (2.4%) and the Southern Rail (2.0%) ECAs.
  • The Gulf ECA had a greater increase in total damage (1.7% to 2.4%) between harvest and export than the other ECAs. The Pacific Northwest ECA had the smallest change in total damage (±0.3%) from harvest samples, which has been the pattern in previous years. Lower moisture and cooler temperatures at harvest may be a partial explanation for the consistent pattern of the smaller change in total damage in this ECA.
  • Average total damage for contracts being loaded as U.S. No. 2 o/b (1.9%), and as U.S. No. 3 o/b (2.1%), were below the limit for U.S. No. 1 grade (3.0%).

4. Heat Damage

Heat damage is a subset of total damage in corn grades and has separate allowances in the U.S. Grade standards. Heat damage can be caused by microbiological activity in warm, moist grain or by high heat applied during drying. Low levels of heat damage may indicate the corn has been stored at appropriate moisture and temperatures prior to delivery to the export point.

RESULTS

  • Average U.S. Aggregate heat damage was 0.0%, same as 2014/2015, 2013/2014 and 4YA.
  • Only five samples in the entire sample set showed any heat damage (0.1% for all five samples) in the 2015/2016 export samples. This number has also been well below the limit for U.S. No. 1 grade in previous years, indicating good management of drying and storage of the corn throughout the market channel.