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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.

SUMMARY: PHYSICAL FACTORS

  • For the U.S. Export Aggregate sorghum samples in 2015/2016, kernel diameter averaged 2.60 mm, TKW averaged 27.57 g, and kernel volume averaged 20.28 mm3, all typical values for kernels from any sorghum sample, except kernel volume, which was on the lower end of the range of values cited in literature.
  • In the 2015/2016 U.S. Export Aggregate samples, kernel true densities averaged 1.360 g/cm3, which was within the range of feed sorghum.
  • Kernel hardness index averaged 71.3 for U.S. Export Aggregate sorghum in 2015/2016, a typical value for any sorghum sample.
  • Average values for kernel diameter, TKW, kernel volume, kernel true density, and kernel hardness index for the NOLA EO were higher than for the Texas EO. While there could be varietal and growing location differences between the EOs, no practical signifcance was tied to the consistent difference between EOs as all observed averages were within the range of values cited in literature for sorghum.
  • Average U.S. Aggregate values for kernel diameter, TKW, kernel volume, true density, and kernel hardness were somewhat higher at export than at harvest. The lower standard deviations for all of these tests at export indicated more uniformity at export than at harvest.

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

  • Kernel diameter averaged 2.60 mm for U.S. Export Aggregate sorghum in 2015/2016, a typical value for any sorghum sample.
  • The kernel diameter values for the 2015/2016 U.S. Export Aggregate samples had a standard deviation of 0.04 mm.
  • Kernel diameters for the U.S. Export Aggregate samples ranged from 2.47 to 2.71 mm in 2015/2016.
  • Average U.S. Export Aggregate kernel diameters were higher than that for U.S. Harvest Aggregate samples (2.53 mm). The standard deviation of export samples was much lower than that for the harvest samples (0.04 mm).
  • In 2015/2016, U.S. Export Aggregate kernel diameters were distributed so that 1.1% of the samples had kernel diameters of 2.70 mm or greater, 97.8% were between 2.50 and 2.69 mm, and 1.1% were less than 2.50 mm.
  • Average kernel diameter was slightly higher for the NOLA EO (2.61 mm) than for the Texas EO (2.57 mm). Both averages fall in the normal range of reported kernel diameter values.

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 g. 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 27.57 g for U.S. Export Aggregate sorghum in 2015/2016, a value in the range of typical TKW values in literature for U.S. sorghum hybrids.
  • The TKW values for the 2015/2016 U.S. Export Aggregate samples had a standard deviation of 0.85 g.
  • TKW for the U.S. Export Aggregate samples ranged from 24.28 to 30.02 g in 2015/2016.
  • Average U.S. Export Aggregate TKW was higher than that for U.S. Harvest Aggregate samples (26.30 g). The standard deviation of export samples was much lower than that for the harvest samples (2.00 g).
  • In the 2015/2016 U.S. Export Aggregate samples, TKW was distributed so that 0.5% of the samples had TKW of 30.00 g or greater and 99.5% had TKW between 24.00 and 29.99 g.
  • Average TKW was higher for the NOLA EO (27.69 g), with less variability than for the Texas EO (27.13 g). Both averages fall in the normal range of reported TKW values.

3. Kernel Volume

Kernel volume (or size), reported in mm3, is directly related to kernel diameter and 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 20.28 mm3 for U.S. Export Aggregate sorghum in 2015/2016, a value on the lower end of typical values for any sorghum sample.
  • The kernel volume values for the 2015/2016 U.S. Export Aggregate samples had a standard deviation of 0.66 mm3.
  • Kernel volumes for the U.S. Export Aggregate samples ranged from 17.91 to 22.12 mm3 in 2015/2016.
  • Average U.S. Export Aggregate kernel volumes were higher than that for U.S. Harvest Aggregate samples (19.34 mm3). The standard deviation of export samples was much lower than that for the harvest samples (1.44 mm3).
  • In the 2015/2016 U.S. Export Aggregate samples, kernel volumes were distributed so that 0.5% of the samples had kernel volumes of less than 18.00 mm3, 98.9% were between 18.00 and 21.99 mm3, and 0.5% were equal to or greater than 22.00 mm3.
  • Average kernel volume was higher for the NOLA EO (20.32 mm3), with less variability than for the Texas EO (20.11 mm3). Both averages fall in the lower end of the normal range of reported kernel volume values.

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. This quality factor is reported as g/cm3. 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 feed sorghum 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

  • Kernel true density averaged 1.360 g/cm3 for U.S. Export Aggregate sorghum in 2015/2016, which falls in the normal range for U.S. sorghum hybrids.
  • The true density values for the 2015/2016 U.S. Export Aggregate samples had a standard deviation of 0.012 g/cm3.
  • True densities for the 2015/2016 U.S. Export Aggregate samples ranged from 1.333 to 1.496 g/ cm3.
  • Average U.S. Export Aggregate true densities were only slightly higher than those for U.S. Harvest Aggregate samples (1.359 g/cm3). The standard deviation of export samples was about the same as that for the harvest samples (0.013 g/cm3).
  • In the 2015/2016 U.S. Export Aggregate samples, kernel true densities were distributed so that 4.4% of the samples were between 1.330 and 1.344 g/cm3, 91.2% between 1.345 and 1.374 g/cm3, and 4.4% greater than or equal to 1.375 g/cm3.
  • Average kernel true density was higher for the NOLA EO (1.363 g/cm3), with greater variability than for the Texas EO (1.349 g/cm3). Both averages fall in the normal range of reported kernel true density values.

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 produces coarser or larger particles than softer sorghum, and requires more energy per mass of sorghum to achieve similar particle-size distribution as soft sorghum during size reduction. 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 71.3 for U.S. Export Aggregate sorghum in 2015/2016, which falls in the normal range for U.S. sorghum hybrids.
  • The kernel hardness index values for the 2015/2016 U.S. Export Aggregate samples had a standard deviation of 2.3.
  • Kernel hardness index for the U.S. Export Aggregate samples ranged from 55.6 to 79.8 in 2015/2016.
  • Average U.S. Export Aggregate hardness index was slightly higher than the U.S. Harvest Aggregate samples (71.0). The standard deviation of export samples was much lower than that for the harvest samples (6.2).
  • In the 2015/2016 U.S. Export Aggregate samples, kernel hardness indices were distributed so that 95.1% of the samples had kernel hardness indices of 60.00 to 79.99, and 4.9% had less than 60.00.
  • Average kernel hardness index was higher for the NOLA EO (73.5), with less variability than for the Texas EO (63.1). Both averages fall in the normal range of reported kernel hardness index values.