Effects Of Cotton Ginning And Lint Cleaning On Sticky Cotton
T.J. Henneberry, ARS Western Cotton Research Laboratory, Phoenix
Ginning and lint cleaning effects on cotton stickiness were minimal but reduced amounts of therhalulose and reduced thermmodetector counts occurred following each lint process. Leaf trash from ginned seed cotton contained trehalulose and melezitose. Removal of leaf trash in ginning and lint cleaning probably accounts for some reduced lint stickiness.
Cotton lint stickiness has become a more pressing problem with increasing whitelly, Bemisia spp., populations iflector and Hocikinson 1989). Aphids may also cause sticky cotton in some areas. Honeydew excreted by pidoem feeding inseets (adults and nymphs) when deposited on lint of open boils remains localized. Discrete honeydew spots adhere to working surfaces of high Speed lint processing machinery in the textile mill. Honeydew can also be a problem during mechanical harvest with spindle pickers (personal comunications with growers) and during cotton ginning (Khalifa and Gameel 1982, Carlson and Moharned 1986). Physiological plant sugars, primanly sucrose, that normally appear in mature cotton fiber are evenly distributed within the lint and geneaally do not cause stickiness Elsner 1983).
Methods and Materials
Seed cotton used in the studies was spindle-picker harvested from fields heavily infested during the season with silverleaf whiteilies, B. argennfolii Bellows and Pening. Cofton lint thennodetector counts were determined as described by Hnishwood and Perkins (1993) at the USDA-ARS Cotton Quality Research Station, Clemson, SC. Thennodetector analysis is accomplished by spreading 2.5 g lint samples between aluminum foil sheets ton owed by heating under pressure. The aluminum foil sheets are subsequently separated and the numbers of sticky spots counted. less than 5 spots indicates nonsticky cofton, S to 14 light stickiness, 15-24 moderate stickiness, and above 24, heavy stickiness merkins and Brusliwood 1995).
The study was condueted to investigate the effects of cotton ginning and lint cleaaang on cotton lint stickiness. Seed cotton mateials and methods samples were taken, in each case, from machine-harvested cotton in silverleaf whitefly infested fields at each of two loaations. Samples were visibly different with respect to leaf trash content. Thermodetector counts for one locailon averaged 11 (n = 5) and 22 (n = 5) for the seoond location. Samples were thereafter designated as lightly sticky and moderately sticky, respectively. Ten subsamples of lighily-sticky and moderately-sticky seed cotton were weighed, ginned, and cotton seed and lint weighed and percentages of trash detennined. Trash (Parts of cotton leaves, stems, etc.) was coilected from each seed cotton sample. Trash was soaked in water, charcoal filtered, floeze dried and analyzed for trehalidose and melezitose honeydew sugars.
Seed cotton was machine-ginned or hand delinted and, in each case, lint was not cleaned or processed through a lint cleaner. Thermodetector counts, trehalidose and nelentose determinations were made for lint samples from all treatments. The experiment was replicated 5 times
Percentages of leaf trash in lightly-sticky cotton and heavily-sticky cotton were 1.44 and 2.15 respectively (Table 1). Amounts of trehalulose and melentose in lint for the two samples were not significantly different. However, lint themodetector counts were significantly higher for cotton contairdng 2.15% leaf flash compared with cotton containing 1.44% leaf trash. Leaf trash contained significant amounts of trehalulose and melezitose with significantly higher amounts, meach case, per gram of leaf trash occurring in the highest leaf trash cotton compared with the lower leaf trash cotton.
Effects of gining were miniamal although oveerall a reduced amount of trehalulose and a slighily lower thermodetector count occurred for machine-ginned vs. hand delinted cotton (Table 2). The overall mean thermodetcctor count for machined ginned seed cotton was 23.2 compared with 20.8 for hand delinted cotton (significantly different P less than or equal to 0.05). Thermodetector counts for lint from moderately-sticky seed cotton and processed through the lint cleaner following ginning were significantly higher than non cleaned or cleaned lint from lightly-sticky seed cotton.
Our data is preliminary but shows significantly lower thermodeteceor counts following commercial ginning and lint cleaning as compered with counts before ginning and cleaning. Ginning and lint cleaning suggest that these activities may indeed influence cotton stickiness. The effects occurred only with modentely-sticky cotton that also had a high trash percentage (2.15 %). No differenees occurred with lightly-sticly cotton with low trash percentages.The results need to be verified in the field under accial harvest and seed cotton processing conditions. laeaf trash from both lightly and moderately-sticky cottons contained thalulose and melezitose but higher amounts were found in the cotton with the highest trash content The cottons were from different locations and results probably occwred because of heavier honeydew deposits on foliage and othee, plant parts at the locanon with the highest leaf trash in the seed cotton. Lint cleaning that physically removes leaf trash containing tihhalulose and melezitose (also other suwirs found in honeydew as well as the plant pans) probably accounts lor reduced thermodeteetor counts in lint cleaned cottons incur studies. Further, emplassis should be given to determining the relationsitips between sticky cottons in the field and sticky cottons following harvest, module storage, ginning, lint clenning, and at the textile mill.
This is a part of publication
AZ1006: "Cotton: A College
of Agriculture Report," 1998, College of
Agriculture, The University of Arizona, Tucson, Arizona,
85721. Any products, services, or organizations that are
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