Determining Future Cotton Variety Fiber Quality Objectives

Much of the fiber property variability exhibited by cotton (Gossypium hirsutum L.) at the textile mill has genetic origins. Therefore, due to the time and expense required to genetically improve fiber quality, it is important that breeders have clearly defined fiber property breeding objectives. The aim of this research was to evaluate the influence that sixteen fiber properties have on open-end and ring spinning yarn tenacity based on a miniature test. Two plantings of nineteen varieties with two rep lications each were made in both Mississippi and South Carolina in 1986. The varieties represented a broad range of types grown across the country. Yarn tenacities of 42 tex ( 14 N _e ) and 27 tex (22 N _e ) open-end and 30 tex (20 N _e ) and 12 tex (50 N _e ) ring miniature spinning were determined for the 152 samples. In general, variety effects were large for all fiber properties, and the variety by environmental interaction was nonsignificant. Therefore, correlations of the varietys' average fiber properties with yarn tenacity over all environments give a good estimate of the varietal influence on yarn tenacity and the association of characteristics. The correlation of yarn tenacity values between the two spinning methods by two yarn sizes per spinning method was high, with an average r ² of 93%. Variety bundle strength determined by the Stelometer (3.2 mm gauge) consistently gave the highest correlation with yarn tenacity, with an average r ² of 89%. Three measures of fineness—Arealometer, Shirley fine maturity test, and Causticaire—resulted in correlations of similar yarn tenacity predictive values, averaging about r ² = 50%. Variety fiber length was also correlated with yarn tenacity, with r ² = 52%. These results show the importance of variety identification for preferred fiber properties and indicate that bundle strength should have a high priority in fiber quality breeding programs.