REFERENCE MODELS FOR COTTON FIBER MATURITY AND FINENESS MEASUREMENTS ON CULTIVATED EGYPTIAN VARIETIES

Micronaire value in cotton fiber assessment is a combined measure of fiber fineness and maturity. Fineness and maturity are important because yarn made from fine fibers is stronger, and mature fibers absorb dye better. So, the fineness and maturity of cotton are important properties for the spinner, grower, dyer and buyer, as well as breeder. These measurements need to be determined reliably, quickly and economically. The objective of the current study is to employ micronire value as a substitute for assessing cotton fineness and maturity for Egyptian cotton with no prior information about these measurements. Models were derived to aid understanding the functional dependence of fineness (H), maturity and micronaire value. All three fiber properties are combinations of wall thickness and perimeter. Variability in (R^2) between each paired of fiber properties (micronaire value (MIC), maturity ratio (M) and fineness (H)) has been employed, to understand the models. The models were computer simulated over the full range of thickness and perimeter values. Three lint grades viz., Fully Good (FG), Good (G), and Fully Good Fair (FGF) from each of eight cultivated varieties were tested at the laboratories of the Grading Research Section, Cotton Research Institute, Giza. All samples were obtained from 2006 and 2007 seasons. Overall results revealing that the experimental will be able to predict the fiber maturity as he can measure the micronaire value of definite a variety with fixed fiber perimeter using this model: Maturity ratio (M) = 0.3238 + 0.5273 (MIC) - 0.0292 (P) R^2 = 0.679** Also, predicting to fiber fineness (H) using micronaire instrument for specific variety with fixed perimeter can be estimated using this equation: Fiber fineness (H)= -7.177+3.34 (MIC) + 3.255(P) R^2 = 0.969