Study On The Fiber Quality And The Classification Of Color Grades Of China's Cotton

The cotton standards are established according to its economic value, use and the demands of the production of agriculture and industry, is criteria and basis to measure and identify cotton .The national cotton standards in operation 《Cotton upland》 (GB1103-1999) evaluate cotton level according to "mature, color and quality of gin" by range estimation.. While the main countries such as the U.S. and Australia etc. used instrument to test quality of cotton in 1970's and drafted test standards of cotton by using instruments.The study centered on cotton's quality index and the evaluate methods of color character. It's the first time ,we are get so much samples in main region of cotton planting , by comprehensively analyzing the sampling indexes of distribution and range from 1999—2003, the tangible regular change pattern of color character of cotton samples' in China from 1972—2004 and American cotton distribution of different types and bands from 1994—2002.Although the coefficients related are small, the results show that there are evidently statistically relations among color characters the main cotton quality indexes, that is, length, strength , micronair ), while the coefficients related among sense test and reflection and yellowness are much bigger. The main quality indexes of cotton shows evident region characters, and coincide with the division of cotton ecological region. It's will be helpful to select properly varieties for farmer and government.The study defines the principles of graded by reflection, classified by yellowness, with standards of three bands, band gap bigger than resolution power of instruments and cotton coverage of high level in the main production provinces, raise the classification scheme that our cotton color grade should be divided into 13 levels of three types. During the cotton year of 2004-2005, the test results are good by using the classification scheme and the color grade chart-drawing at 22 points testing by instruments in 17 main production provinces of China. We can get more precise data of cotton quality .reduce the times of test, especially we can save the cost of cotton mill.As for the promotion of instrument test of cotton quality, the article finally put forward useful advices that government should consider the relations about two sets of standard, price system, policy-supporting and more tests and verifications.