Cotton Varieties and Classification
category
Commercial cotton is produced from four domesticated Gossypium species: G. hirsutum (upland cotton, 90% of world production, staple length 22–32 mm, micronaire 3.5–5.0), G. barbadense (extra-long staple ELS, 8% of production, staple 35–60 mm, micronaire 2.5–4.0, includes Egyptian Giza and Pima/Supima varieties), G. arboreum and G. herbaceum (Asian cottons, <2% combined). Within G. hirsutum, over 1,000 commercial varieties are classified by staple length: short staple (<25 mm), medium staple (25–28 mm), long staple (28–34 mm), and extra-long staple (>34 mm). HVI (High Volume Instrument) testing measures 10 key fibre properties including upper half mean length (UHML), uniformity index (UI), strength, elongation, micronaire, colour (Rd brightness and +b yellowness), and trash content. USDA cotton classing assigns grade based on colour, leaf, and preparation.
Role
Cotton variety selection and classification determines the optimal spinning system, yarn count range, end-use suitability, and price premium achievable, directly linking agricultural production decisions to textile mill processing specifications and consumer product performance.