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ARS Home » Southeast Area » Stoneville, Mississippi » Cotton Ginning Research » Research » Publications at this Location » Publication #264136
Title: Cultivar differences in fiber-seed attachment force: Measurement techniques

Author
item Boykin Jr, James
item Bechere, Efrem
item MEREDITH, WILLIAM - Retired ARS Employee

Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: 1/28/2011
Publication Date: 4/1/2011
Citation: Boykin Jr, J.C., Bechere, E., Meredith, W. 2011. Cultivar Differences in Fiber-seed Attachment Force: Measurement Techniques. In Proc. Beltwide Cotton Conf, Atlanta, GA. 4-7 Jan. 2011. CD ROM pp 594-601.

Interpretive Summary: Cotton production in the U.S. is struggling at all levels to remain profitable in an increasingly competitive world market. Two key factors for increased profits in the cotton ginning industry are increased productivity and reduced energy usage. In addition, increased fiber quality elevates the monetary value of the product (cotton bales) while maintaining the reputation of high quality associated with U.S. cotton. Cotton cultivars are well known to differ in yield and fiber quality, and they also differ in how strongly fibers are attached to seed. Cultivars with low fiber-seed attachment force have the potential to be ginned faster with less energy and less fiber damage. The overall objective of this project was to develop cultivars with improved “ginning efficiency” while preserving yield and fiber quality. Improved ginning efficiency as defined in this study included both reduced ginning energy and increased ginning rate. Initial results for 46 cultivars showed significant variation in energy usage, ginning rate, and other fiber properties. So, the specific objective of this study was to validate the assumption that these properties were related to fiber-seed attachment force. A pendulum-type fiber-seed attachment tester was used to directly measure fiber-seed attachment force for these cultivars. This was a very laborious task. Energy consumption and ginning rate can be measured much more easily. Energy consumption by the gin stand ranged from 30 to 48 Wh/kg lint, and ginning rate ranged from 2.5 to 3.3 g lint/sec. Fiber-seed attachment force was found to vary statistically among cultivars ranging from 30 to 47 cN*cm/mg fibers. A very significant positive correlation was found between fiber-seed attachment force and gin stand energy verifying the assumption that cultivar differences in gin stand energy were largely related to differences in fiber-seed attachment force. Both fiber-seed attachment force and gin stand energy were slightly negatively correlated with ginning rate hinting that cultivars with low fiber-seed attachment force ginned faster. These findings will be critical in future studies evaluating cultivar differences in fiber-seed attachment force by measuring gin stand energy consumption and ginning rate.

Technical Abstract: Cotton cultivars are well known to differ in yield and fiber quality, and they also differ in how strongly fibers are attached to seed. Cultivars with reduced fiber-seed attachment force have the potential to be ginned faster with less energy and less fiber damage given that all other properties are the same. The overall objective of this project was to develop cultivars with improved “ginning efficiency” while preserving yield and fiber quality. Improved ginning efficiency as defined in this study included both reduced net gin stand energy usage (that above idling) and increased ginning rate. Initial results for 46 cultivars including 6 semi-naked seeded cultivars ginned on a 10-saw gin stand showed significant variation in net gin stand energy usage, ginning rate, and other fiber properties; so the specific objective of this paper was to determine how these properties related to fiber-seed attachment force measured with a pendulum-type tester. A sub-set of the 46 cultivars including 15 total cultivars (2 semi-naked seeded cultivars) was tested in this experiment which included a wide range of net gin stand energy (30 to 48 Wh/kg lint) and ginning rate (2.5 to 3.3 g lint/sec). Approximately 45 seeds were tested per cultivar, and fiber-seed attachment force was measured for two tufts of fiber on each side of the seed (four tufts per seed) with two tufts oriented towards the chalazel (rounded) end of the seed and two tufts oriented towards the micropyle (pointed) end of the seed. Fiber-seed attachment force was found to vary statistically among cultivars ranging from 30 to 47 cN*cm/mg fiber when averaged over seed ends. A significant positive correlation was found between fiber-seed attachment force and net gin stand energy verifying the assumption that cultivar differences in net gin stand energy were largely related to differences in fiber-seed attachment force. Both fiber-seed attachment force and net gin stand energy were slightly (statistically insignificant) negatively correlated with ginning rate hinting that cultivars with low fiber-seed attachment force ginned faster. It was suspected that the trends were masked by ginning small samples on the 10-saw gin. Fiber-seed attachment force and net gin stand energy both increased significantly with ginned seed fuzz (% by weight) and the number of AFIS seed coat neps (SCN). These results suggested that seed fuzz levels are an indicator of fiber-seed attachment force and that increased fiber-seed attachment force resulted in seed coat fragmentation. Net gin stand energy was positively correlated with fiber length and strength and negatively correlated with fiber fineness, but these properties were not correlated with fiber-seed attachment force. Future studies may measure net gin stand energy consumption to indicate relative differences in fiber-seed attachment force among cultivars, but the effects of fiber length, strength, and fineness should be considered in the interpretation of results. Further study is needed to interpret ginning rate measured on a 10-saw gin stand.