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2015/2016 Sorghum Harvest and Export Quality Report

Contents

  1. Harvest Quality Highlights
  2. Export Quality Highlights
  3. Introduction
  4. Harvest Quality Test Results
  5. Moisture
  6. Physical Factors
  7. Mycotoxins
  8. Export Quality Test Results
  9. Moisture
  10. Chemical Composition
  11. Physical Factors
  12. Mycotoxins
  13. Crop and Weather Conditions
  14. Planting and Early Growth Conditions
  15. Late Vegetative and Mid-Pollination Conditions
  16. Maturity and Harvest Conditions
  17. Comparison of 2015 to 2010-2014
  18. U.S. Sorghum Export System
  19. U.S. Sorghum Export Flow
  20. Impact of the Sorghum Market Channel on Quality
  21. U.S. Government Inspection and Grading
  22. U.S. Sorghum Production, Usage and Outlook
  23. U.S. Sorghum Use and Ending Stocks
  24. Outlook
  25. Harvest Survey and Statistical Analysis Methods
  26. Survey Design and Sampling
  27. Statistical Analysis
  28. Export Survey and Statistical Analysis Methods
  29. Survey Design and Sampling
  30. Statistical Analysis
  31. Testing Analysis Methods
  32. Sorghum Grading Factors
  33. Moisture
  34. Chemical Composition
  35. Physical Factors
  36. Mycotoxin Testing
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D.Physical Factors

Physical factors include other quality attributes that are neither grading factors nor chemical composition. Tests for physical factors provide additional information about the processing characteristics of sorghum for various uses, as well as its storability and potential for breakage in handling. The storability, the ability to withstand handling, and the processing performance of sorghum are influenced by sorghum’s morphology. Sorghum kernels are morphologically made up of three parts: the germ or embryo, the pericarp or outer covering, and the endosperm. The endosperm represents about 82 to 86% of the kernel, and consists of soft (also referred to as floury) endosperm and of hard (also called vitreous) endosperm, as shown to the right. The endosperm contains primarily starch and protein whereas the germ contains oil and some proteins. The pericarp is comprised mostly of fber, with a small coating of waxy material. D.Physical Factors Physical factors include other quality attributes that are neither grading factors nor chemical composition. Tests for physical factors provide additional information about the processing characteristics of sorghum for various uses, as well as its storability and potential for breakage in handling. The storability, the ability to withstand handling, and the processing performance of sorghum are influenced by sorghum’s morphology. Sorghum kernels are morphologically made up of three parts: the germ or embryo, the pericarp or outer covering, and the endosperm. The endosperm represents about 82 to 86% of the kernel, and consists of soft (also referred to as floury) endosperm and of hard (also called vitreous) endosperm, as shown to the right. The endosperm contains primarily starch and protein whereas the germ contains oil and some proteins. The pericarp is comprised mostly of fber, with a small coating of waxy material.

SUMMARY: PHYSICAL FACTORS

  • For the U.S. Harvest Aggregate sorghum samples in 2015, kernel diameter averaged 2.53 mm, TKW averaged 26.30 g, and kernel volume averaged 19.34 mm3.
  • U.S. Harvest Aggregate kernel true density averaged 1.359 g/cm3 in 2015, with a range from 1.295 to 1.402 g/cm3 and 88% of samples between 1.345 g/cm3 and 1.389 g/cm3.
  • On average, the U.S. Harvest Aggregate samples had less volume than typical for U.S. sorghum hybrids, but kernel diameter, weight, and true density were within the range of values reported in literature for commercial sorghum hybrids.
  • Kernel hardness index averaged 71.0 for U.S. Harvest Aggregate samples in 2015, with a range from 37.1 to 91.5 and 90% of samples between 40.00 and 79.99.

1. Kernel Diameter

Kernel diameter (reported in mm) directly correlates with kernel volume, affects size reduction behavior and material handling practices, and may indicate maturity of kernels. Size reduction refers to reducing kernels (large particles) to ground material (small particles), commonly through grinding/milling. Size reduction, energy consumption, decortication effciency, and yield of kernel components depend on diameter. Decortication refers to the removal of the pericarp and germ from a kernel by attrition or abrasion, with minimal removal of endosperm before subsequent grinding/milling. The smaller the kernels, the more care and concern required in handling. Incomplete kernel fill and unexpected weather conditions may contribute to small diameter values.

RESULTS

  • U.S. Harvest Aggregate kernel diameter averaged 2.53 mm in 2015, a typical value for any commercial sorghum hybrid sample.
  • The kernel diameter values for the 2015 U.S. Harvest Aggregate samples had a standard deviation of 0.09 mm. Kernel diameters for the U.S. Harvest Aggregate samples ranged from 2.18 to 2.90 mm in 2015.
  • In 2015, U.S. Harvest Aggregate kernel diameters were distributed so that 11.1% of the samples had kernel diameters of 2.70 mm or greater, 52.7% were between 2.50 and 2.69 mm, and 36.2% were less than 2.50 mm.

2. 1000-Kernel Weight (TKW)

1000-kernel weight (commonly referred to as TKW) is the weight for a fxed number of kernels, and is reported in grams. Kernel volume (or size) can be inferred from TKW, since as TKW increases or decreases, kernel volume will proportionally increase or decrease. Kernel volume affects drying rates. As kernel volume increases, the volumeto-surface-area ratio for the kernel becomes greater, and drying time to a desired moisture takes longer. Kernel weights tend to be higher for specialty varieties of sorghum that have high amounts of hard (vitreous) endosperm.

RESULTS

  • TKW averaged 26.30 g for U.S. Harvest Aggregate samples in 2015, a value within the range of typical TKW values in literature for U.S. sorghum hybrids.
  • The TKW values for the 2015 U.S. Harvest Aggregate samples had a standard deviation of 2.00 g.
  • TKW for the U.S. Harvest Aggregate samples ranged from 19.49 to 34.66 g in 2015.
  • In the 2015 U.S. Harvest Aggregate samples, TKWs were distributed so that 8.7% of the samples had TKW of 30.00 g or greater, 74.9% had between 24.00 and 29.99 g, and 16.4% less than 24.00 g.
  • The slightly greater average TKW for Late Harvest samples (26.46 g) than the average TKW for Early Harvest samples (25.97 g) generally parallels the trend observed for respective sample test weight averages.

3. Kernel Volume

Kernel volume (or size), reported in mm3, is directly related to kernel diameter and is often indicative of growing conditions. If conditions are dry, kernels may be small due to stunted development. If drought hits later in the season, kernels may have lower fill. Small kernels are more diffcult to handle and, due to their having a greater surface-area-to-volume ratio than large kernels, greater amounts of endosperm are removed during decortication, reducing yield of endosperm-derived products.

RESULTS

  • Kernel volume averaged 19.34 mm3 for U.S. Harvest Aggregate samples in 2015, a value on the lower end of typical volume values in literature for any commercial sorghum hybrid sample.
  • The kernel volume values for the 2015 U.S. Harvest Aggregate samples had a standard deviation of 1.44 mm3.
  • Kernel volumes for the U.S. Harvest Aggregate samples ranged from 14.31 to 25.40 mm3 in 2015.
  • In the 2015 U.S. Harvest Aggregate samples, kernel volumes were distributed so that 21.2% of the samples had kernel volumes of less than 18.00 mm3, 71.1% were between 18.00 and 21.99 mm3, and 7.9% were equal to or greater than 22.00 mm3. The kernel volume average for Late Harvest samples (19.40 mm3) was slightly higher than the average for Early Harvest samples (19.22 mm3).
  • Kernel volume had a positive relationship (a correlation coeffcient of 0.85) with kernel diameter for the 2015 U.S. Harvest Aggregate samples, as shown in the adjacent figure

4. Kernel True Density

Kernel true density (kernel weight per kernel volume, reported as g/cm3) is a relative indicator of kernel hardness, which is useful during size reduction operations. Genetics of the sorghum hybrid and the growing environment affect kernel true density. Sorghum with higher density is typically less susceptible to breakage in handling than lower-density sorghum. Most sorghum used for feed has true density values ranging from 1.330 to 1.400 g/cm3. Sorghum with density greater than 1.315 g/cm3 is judged suitable for processing to brewers’ grits and stiff porridge, whereas sorghum with density less than 1.315 g/cm3 is suitable for processing into soft bread flour and starch.

RESULTS

  • U.S. Harvest Aggregate kernel true density averaged 1.359 g/cm3 in 2015, which falls within the range of values in literature for U.S. sorghum hybrids.
  • The true density values for the 2015 U.S. Harvest Aggregate samples had a standard deviation of 0.013 g/cm3. True densities for the 2015 U.S. Harvest Aggregate samples ranged from 1.295 to 1.402 g/cm3.
  • In the 2015 U.S. Harvest Aggregate samples, kernel true densities were distributed so that 1.9% of the samples were below 1.315 g/cm3, 4.3% between 1.315 and 1.329 g/cm3, 4.8% between 1.330 and 1.344 g/cm3, and 88.9% between 1.345 g/cm3 and above.
  • The slightly greater average true densities for Late Harvest samples (1.364 g/cm3) than the average true densities for Early Harvest samples (1.350 g/cm3) generally parallels the trend observed for respective sample test weight averages.

5. Kernel Hardness Index

Kernel hardness affects resistance to molds and insects, size reduction behavior, and the end use of sorghum. Sieving behavior, size reduction energy consumption, particle size distribution of ground material, and yield of kernel components depend on hardness. Harder sorghum not only produces coarser or larger particles than softer sorghum; it also requires more energy per mass of sorghum to achieve similar particle size distribution during size reduction. As a result, grinding/milling for optimum particle size for livestock or poultry feed may be costlier for harder sorghum than for softer sorghum. Test weight and kernel density correlate with hardness. Kernel hardness index is a dimensionless number, with increasing value indicating kernels increasing in physical hardness.

RESULTS

  • Kernel hardness index averaged 71.0 for U.S. Harvest Aggregate samples in 2015, a typical value for any commercial sorghum hybrid sample.
  • The kernel hardness index values for the 2015 U.S. Harvest Aggregate samples had a standard deviation of 6.2.
  • Kernel hardness index for the U.S. Harvest Aggregate samples ranged from 37.1 to 91.5 in 2015. In the 2015 U.S. Harvest Aggregate samples, kernel hardness indices were distributed so that 9.7% of the samples had kernel hardness indices of 80.00 or greater, 89.8% had 40.00 to 79.99, and 0.5% had less than 40.00.
  • The slightly greater average kernel hardness index for Late Harvest samples (72.3) than the average kernel hardness index for Early Harvest samples (68.5) generally parallels the trend observed for respective sample test weight averages.
  • Kernel hardness had a weak but positive relationship with true density (a correlation coeffcient of 0.71), as shown in the adjacent figure.