Variations of Mature Cotton Fiber Tensile Properties: Association with Seed Position and Fiber Length

Abstract

Variations in single fiber tensile properties of mature cotton fibers are investigated with respect to their association with seed positions and fiber-length groups within individual locules. Fibers from five varieties representing four cultivated cotton species ( G. herbeceum, G. arboreum, G. hirsutum, and G. barbadense) are included in this study. With the exception of G. arboreum, breaking forces, toughness, and linear density are highly dependent on the seed position in the locule, and the dependence is especially high for G. herbeceum and G. barbadense. Fibers from seeds located closer to the main stem have higher breaking forces and linear densities, indicating their association with the distribution of nutrition resources. The relationships between single fiber tensile properties and fiber lengths vary among these cotton species. Breaking force and tenacity are independent of fiber length for G. barbadense, whereas fiber-length dependence is positive for G. herbeceum and G. arboreum, and there is a negative trend for the Maxxa variety of G. hirsutum. For G. herbeceum and G. arboreum, longer fibers have higher breaking forces, whereas the opposite is true for Maxxa. Single fiber breaking elongation decreases with increasing fiber length for all except G. barbadense. Overall variations of single fiber tensile properties are associated more strongly with the seed position in the locule than with the fiber length.