Analysis On The Present Situation And Restricting Factors Of Cotton Fiber Quality In Aksu Region

Aksu region is an important production base of high-quality commercial cotton in China and occupies an important position in the cotton industry strategy of Xinjiang.In recent years,Aksu region has vigorously promoted the cultivation of machine picked cotton,and the cotton output is increasing year by year,but the quality of cotton has not been improved accordingly.The problem of deterioration of raw cotton quality is becoming increasingly prominent,which is difficult to meet the actual needs of textile enterprises.Cotton quality has become a prominent problem restricting the industrial development in Aksu region.Based on the current situation of cotton quality in Aksu region in recent 5 years,this paper explores the main factors affecting cotton quality.The main results are as follows:(1)From the development of cotton production and the present situation of cotton fiber quality in Aksu region,the cotton planting region in Aksu region showed a downward trend from 2018 to 2020,the output has been relatively stable at more than 1 million tons,but the cotton fiber quality has not been improved accordingly.Through the analysis of cotton quality in Aksu region from 2016 to 2020,it is found that the main indexes of cotton fiber show a downward trend except the breaking specific strength.Compared with the average level of the whole country and Xinjiang,the average length of cotton fiber in Aksu region in 2018 and 2019 is lower than that of the whole country and Xinjiang,and slightly better than that of the whole country and Xinjiang in 2020,which is 28.7mm;The proportion of Micronaire level B and above has been lower than the national level for three years,and the lowest in 2020,68.36%;The average fracture specific strength in 2018 and 2019 is lower than the average level of the whole country and Xinjiang;But in 2020,it is slightly higher than the average level of the whole country and Xinjiang.On the whole,the cotton fiber quality in Aksu region not only has the phenomenon of decline in color grade quality,short length and insufficient maturity,but also has poor consistency of cotton fiber quality and weak overall quality.(2)From the comparison test of main cotton varieties in Aksu region,under the unified cultivation mode,the seed cotton yield of j206-5 is the highest,6856.5kg/hm~2,The main physical indexes such as the average fiber length of j206-5 are 29.97mm,4.63(B2 grade)84.36%,31.63cn/tex,14.23%and 8.65%respectively.It has obvious advantages.Through the comprehensive analysis of grey correlation degree,it is j206-5>Xinluzhong 84>Xinluzhong 80>Xinluzhong 68>Xinluzhong 62.Through the analysis of difference and adaptability,it is found that the cotton quality in the east of Aksu region is good,and the evaluation of j206-5 is good,with the best yield,stability and adaptability,which is suitable for popularization and planting in Aksu region;Xinluzhong 84’s cotton quality indicators are good,but the yield and stability are general,and the adaptability of planting in Aksu region is general;Xinluzhong 80 is a special adaptive variety,which is suitable for planting under high water and fertilizer conditions.Therefore,j206-5 should be the main variety in Aksu region,and Xinluzhong 84 and Xinluzhong 80 should be the auxiliary varieties.(3)From the influence of different picking methods on cotton fiber quality,there is a very significant difference between mechanical picking and manual picking.The main physical indexes such as the average length of cotton fiber after mechanical picking in Xinluzhong 80 are 29.08mm,4.17(grade A),28.13cn/tex,82.05%and 16.72%respectively;The values after manual picking are:30.83mm,4.58(grade B2),31.89cn/tex,84.59%,12.96%.,Except for Micronaire value,other indexes of cotton fiber after mechanical picking are lower than those after manual picking,indicating that the mechanical cotton picking industry in Aksu region is still not mature enough,and the agronomic measures and supporting technologies of mechanical cotton picking need to be further strengthened and improved.In addition,there is no obvious difference in the indexes of picking the same variety of cotton with two different cotton pickers,indicating that different picking machines have little effect on the physical indexes of cotton.(4)In terms of the impact of the main processing procedures of machine picked cotton on the quality of cotton fiber,seed cotton cleaning has the greatest impact on the number of impurity particles and color grade.After seed cotton cleaning,the number of impurity particles shows a very significant downward trend.At the same time,the reflectivity and yellow depth of cotton fiber increase,and the length uniformity and short fiber rate of cotton fiber show a downward trend after seed cotton cleaning,The effect of seed cotton cleaning on fiber length and micronaire value was small;The effect of ginned cotton cleaning on fiber length and length uniformity is mainly negative,showing a decreasing trend,but the breaking specific strength has an upward trend after ginned cotton cleaning.Ginned cotton cleaning had little effect on micronaire value,short fiber index and color grade.