Yield and Turnout
Yield – Pounds of lint harvested per acre.
Gin Turnout
Lint – Percentage of lint of the stripper-harvested cotton.
Seed – Percentage of seed of the stripper-harvested cotton.
Agronomic Properties – Determined from hand-snapped samples.
Percent Lint
Picked – Lint fraction of seed cotton.
Pulled – Lint fraction of burr cotton.
Boll Size – Weight, in grams, of seed cotton per boll.
Seed Index – Weight, in grams, of 100 fuzzy seed.
Lint Index – Weight, in grams, of lint from 100 seed (calculated).
Seed Per Boll – Average number of seed per boll (calculated).
Maturity and Storm Resistance
Percent Open Bolls – Percentage of open bolls on a given date. Storm Resistance – Visual rating from 1 (very loose boll type, considerable seed cotton loss) to 5 (very tight boll types, no seed cotton loss).
Statistical Analysis
Mean – The average value for the trait being observed. C.V.,% – Coefficient of variation. A statistical measure of the variability within a test, and expressed as percentage. LSD – Least significant difference. If the difference between two means exceed this value, the two means are significantly different at the 0.05 probability level.
Fiber Properties – Measured by High Volume Instrument (HVI)
Micronaire – A relative measure of fiber linear density (mass per unit length) determined by air permeability.
| Market Value | HVI Micronaire |
| Discount range | 3.4 and below |
| Base range | 3.5 – 3.6 |
| Premium range | 3.7 – 4.2 |
| Base range | 4.3 – 4.9 |
| Discount range | 5.0 and above |
Source: USDA (1995)
Length – An instrument measure of fiber length, expressed in hundredths of a inch, which approximates the classer’s staple length.
| Staple 32nds | HVI Length |
| 30 | .93 – .95 |
| 31 | .96 – .98 |
| 32 | .99 – 1.01 |
| 33 | 1.02 – 1.04 |
| 34 | 1.05 – 1.07 |
| 35 | 1.08 – 1.10 |
| 36 | 1.11 – 1.13 |
| 37 | 1.14 – 1.17 |
| 38 | 1.18 – 1.20 |
Source: USDA (1995)
Uniformity – A measure of the uniformity of fiber length in a sample, expressed as a percentage.
| Uniformity group | HVI Uniformity |
| Very high | 86 and above |
| High | 83 – 85 |
| Intermediate | 80 – 82 |
| Low | 77 – 79 |
| Very Low | 76 and below |
Source: USDA (1995)
Strength – The force required to rupture (or break) a fiber sample, expressed in grams per tex.
| Strength group | HVI Strength |
| Very strong | 31 and above |
| Strong | 29 – 30 |
| Intermediate | 26 – 28 |
| Weak | 24 – 25 |
| Very weak | 23 and below |
Source: USDA (1995)
Elongation – The amount that a fiber sample will stretch prior to breakage. This is a measure of the deformation of fiber at rupture expressed as percent change in length based on the original fiber length.
Rd – Degree of reflectance. This measures how light or dark the fiber sample is, expressed as a percentage. Lower Rd values indicate a grayer sample. +b – Yellowness. This measures the degree of color pigmentation. Higher +b value indicate yellower samples. Color Grade – A function of the Rd and +b of the fiber sample. The color grade indicates the quadrant of the Nickerson-Hunter cotton colorimeter diagram in which Rd and +b values intersect.
