1) Staple Length

• Definition: Average fiber length, reported as UHM (upper-half mean) or equivalent measure.

• Unit: Inches (″) or mm.

• Market ranges / thresholds: Upland cotton typically 1.00″–1.25″ (25.4–31.75 mm); commercial “premium” range around 1 1/8″–1 5/32″ (~28.6–29.4 mm); Extra-Long Staple (ELS, Pima) ≥ 1 3/8″ (~34.9 mm) [1][12].

• Contract notation: “Staple 29 mm” or “1 1/8″”; ≥32 mm usually refers to ELS segment [1].

• Note: Staple length directly enters premium/discount tables [1].

2) Fiber Strength (Tenacity)

• Definition: Breaking strength of the fiber, resistance to rupture during spinning.

• Unit: g/tex.

• Market ranges / thresholds: ~28–30 g/tex = medium to strong; ≈30 g/tex and above = strong/premium [1][3].

• Contract notation: “Strength ≥ 30 g/tex” appears in offers/specs; loan schedules also apply strength points [1][3].

3) Micronaire

• Definition: Composite index of fineness and maturity.

• Unit: Micronaire units.

• Market ranges / thresholds: USDA loan tables classify ≈3.7–4.9 as preferred; <3.5 and ≥5.0 incur penalties [5][6][7].

• Contract notation: “MIC 3.8” or “MIC 4.2” are common; micronaire band determines premium/discount [5].

4) Color — Rd (Reflectance) and +b (Yellowness)

• Definition: Rd = brightness/reflectance; +b = yellowness. Combined into USDA color–leaf grades.

• Unit: Rd (%) and +b units → Color Grade code (e.g., 21, 31) plus leaf code (e.g., -1, -2) [1][2].

• Market ranges / thresholds: Higher Rd (≥77) indicates brighter; Color Grade codes 21, 31, etc., used in trade [1].

• Contract notation: “31-1” or “21-1”; first number = color band, suffix = leaf grade [1][2].

5) Foreign Matter and Contamination (Trash / Extraneous)

• Definition: Trash = leaf, bark, dust; Extraneous = plastic, metal, jute, rope, synthetics.

• Unit: Trash %; extraneous contamination codes.

• Market ranges / thresholds: Trash ≤3% seen as clean; plastic contamination penalized heavily (e.g., –4000 points in loan schedule) [6][7].

• Contract notation: “Extraneous: plastic” = discount or rejection; round module wrap cutting is a key risk [6][7][11].

6) Moisture

• Definition: Water content of the bale.

• Unit: % (wet basis).

• Market ranges / thresholds: U.S. regulation defines ≥7.5% WB as a “wet bale” [3][4]. Buyers typically demand <7.5–8% WB for safe storage.

• Contract notation: “Wet bale” label = loan ineligible and discounted [3][4].

7) Uniformity Index and Short Fiber Index (SFI)

• Definition: Uniformity = degree of homogeneity in fiber length; SFI = proportion of fibers <0.5″ (12.7 mm).

• Unit: Uniformity (%) and SFI (%).

• Market ranges / thresholds: Uniformity ~80–85 = average/high; SFI <8–10% generally required [8].

• Contract notation: “Uniformity 83,” “SFI 6.5%” appear in offers/specs [8].

References

[1] USDA AMS – Cotton Classification: Understanding the Data
[2] Cotton Incorporated – Classification of Upland Cotton
[3] ECFR, 7 CFR §1427 – Definition of “Wet Cotton” (≥7.5% WB)
[4] USDA ARS – CAT-scanning Cotton Bales for Moisture
[5] CCC Loan Premium & Discount (Upland) – Micronaire tables
[6] FSA – Upland Loan Schedule (2025)
[7] Cotton Incorporated – Proper Cutting of Plastic Wrap on Round Modules
[8] USTER® HVI – Uniformity & Short Fiber Index ranges
[9] USDA ARS – Sticky Cotton: Causes, Effects, and Prevention
[10] UGA Extension – Sampling & Managing Whiteflies (2023)
[11] Journal of Cotton Science – Effects of Gin Machinery on Cotton Quality
[12] USITC – Industry and Trade Summary: Cotton