much of the fiber property variability exhibited by cotton (gossypium hirsutum l.) at the textile mill has genetic origins. 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 replications 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. 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 $equals$ 50. variety fiber length was also correlated with yarn tenacity, with r**2 $equals$ 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. (edited author abstract) 7 refs