Title: Seed Coat Fragments, Motes, and Neps: Cultivar Differences Author
Submitted to: Journal of Cotton Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 13, 2008
Publication Date: July 21, 2008
Citation: Boykin Jr, J.C. 2008. Seed Coat Fragments, Motes, and Neps: Cultivar Differences. Journal of Cotton Science. 12: 109-125. Interpretive Summary: Approximately 20 million bales of cotton are produced in the U.S. annually, most of which is exported. It is important that this cotton is processed efficiently while maintaining the quality demanded by domestic and foreign consumers. Problems associated with fragments of cottonseed that remain in cotton bales after ginning is one issue that is becoming increasingly important. These seed coat fragments (SCF) can cause the yarn to break resulting in costly down time in the mill. In addition, when the yarn or fabric is dyed, the SCF absorb the dye differently than the cotton lint and cause discoloration that is undesirable in the finished product. Neps and motes cause similar problems for mills, and the sources of these components may be related. There has been much research conducted in mills to deal with this contamination, and cotton breeders have attempted to develop better cottons. The purpose of this experiment was to determine cultivar differences in SCF, neps, and motes and to relate differences to other properties of cotton. A total of 104 types of cotton were processed through typical gin processes, and lint was analyzed. Cotton varieties were found to vary in SCF content by over 100%. There were several varieties of cotton that stood out as having either very low or very high levels of both SCF and seed coat neps, so cotton genetics offer part of the solution to reducing these levels in lint. This research identifies the possibilities of decreasing seed coat fragment contamination by choosing varieties with less contamination. It also indicates that there is room for considerable progress to be made in cotton breeding programs to reduce the seed coat fragment potential for new varieties. Results from this report will be vital to future research aimed at preventing or reducing SCF contamination in cotton bales. Implementation of this knowledge will help to increase the competitiveness of U.S. cotton.
Technical Abstract: Cotton lint with high levels of neps and seed coat fragments (SCF) causes problems for textile mills. It can be difficult to spin into yarn, and the fabric can be difficult to dye. Cultivars grown in three tests within the Mississippi Regional Cotton Variety Trial were processed through a typical gin sequence and analyzed manually for SCF and motes in the lint. The Advanced Fiber Information System (AFIS) was used to analyze neps and seed coat neps (SCN) in lint. These results were used to characterize cultivars, identify interactions for cultivars repeated in multiple tests, and identify trends between measurements. The most discernable difference between cultivars was found for AFIS neps, ranging from 140 to 292 neps/g lint. Differences were also found between cultivars in each test for the number of SCF and AFIS SCN, and differences were seen between cultivars in two tests for the number of motes. Across cultivars in all tests, the number of manually counted SCF ranged from 6 to 35 and averaged 13.1 SCF/g lint, and AFIS SCN ranged from 6 to 22 and averaged 11.1 SCN/g lint. The correlation (r) between manual SCF and AFIS SCN ranged from 0.59 in one test to 0.84 in another, so these measurements were similar. Analysis revealed that these measurements yielded statistically different results. For the 19 cultivars common between tests, three cultivars (SG215BR, BCG28R, and SG105) were statistically equal to the minimum for both SCF and SCN content, and DES810 had the highest number of both. Only one measurement, AFIS nep count, revealed a significant interaction for cultivars across tests. For other measurements, cultivar differences were consistent in each test.