The introduction of the John Deere 7760 spindle harvester to the Australian cotton industry in 2008, with on board module building capacity producing round modules, has led to the rapid uptake of this technology by growers due to a reduction in labor requirements. There have, however, been anecdotal reports from cotton classing facilities and growers that the quality of cotton harvested by the John Deere 7760 is different and more variable compared to cotton harvested by the conventional spindle basket harvesting and separate module building method. The aim of this research was to compare the average fiber quality and the variability of quality between bales of cotton produced by these two harvesting methods. Four fields located in the southern and central cotton growing areas of Australia were planted with two popular upland varieties. Alternate groups of rows across each field were harvested using either the round module or conventional basket harvesting method, with harvested seed cotton ginned at the same gin. Fiber samples were assessed for quality attributes typically used to class and value cotton in Australia. There was no significant difference of average results between the two harvest methods for High Volume Instrument (HVI) determined upper half mean length and bundle strength. However, HVI micronaire was marginally yet significantly lower and HVI reflectance higher for fiber from the round module system, which was attributed to the round harvesters being able to harvest more fiber (including immature fiber from the top of plants) and less trash. The small difference in reflectance, however, did not translate into a practical difference, with there being no significant difference measured between the two harvesting systems for visually determined color and leaf grade. The normalized variability (% coefficient of variation) of fiber quality between bales was greater for the round module system, which was attributed to less blending during the sequential ginning of round modules in contrast to the vertical building of equivalent multiple (round module) layers of seed cotton in larger conventional modules that undergo more blending when fed longitudinally into the gin. While the round modules in this research were harvested and ginned according to industry standards and in sequence, less than favorable in-field conditions and out-of-sequence ginning would more than likely compound the variation in fiber quality between bales. The impact of these variables on fiber quality would have significant practical implications, which will require further investigation.

With the increased demand for quality and the production of finer, longer and stronger Upland cottons, an increasing proportion of these cottons are ginned on roller gins to preserve and improve fiber quality. However, although the benefits of roller ginning on lint turn out and fiber quality are fairly well understood, it is still unclear whether these improvements translate into improved yarn quality and processing performance. The aim of this research was to compare the impact of saw and roller ginning on Long Staple Upland cotton in a high-production and commercial environment and to evaluate quality and textile processing performance in a commercial textile mill. One field located within the central cotton growing area of Australia was planted with a Long Staple Upland variety, with a number of round modules selected at random from the field and processed by a saw and a rotary knife roller gin. There was a significant difference between the two ginning methods in some of the average fiber results, with the roller ginned fiber longer and more uniform with fewer short fibers and fibrous neps, as well as stronger with higher elongation. These improved fiber properties resulted in significant differences in the fine count combed hosiery ring spun yarn produced. On average the yarn spun from roller ginned cotton was significantly more even with fewer total imperfections, although there was no significant difference in yarn count, strength, elongation and hairiness. There were also no significant differences in terms of processing performance, fabric handle, appearance and strength.The purpose of ginning is to convert seed cotton into cotton fiber, which is a saleable and processable commodity. The process of ginning involves separating the fiber from the seed, which was historically done by hand. As this was laborious and slow the process has since been replaced by machines, with the modern ginning process a combination of thermal, pneumatic and mechanical processes. 1 The layout, size, type and technology of the gin may take on a number of forms, which depends mainly on the type of cotton grown, the production and harvesting conditions and economic factors, as well as consumer requirements. 2 There are essentially two ginning methods, namely saw and roller. [2][3][4][5][6][7] Saw gins are generally used to process Upland cotton (Gossypium hirsutum L.) with short to medium staple length (<1 inch to 1 7/32 inch), whereas roller gins are used to process Extra Long Staple (ELS) cottons (Gossypium barbadence L.) with longer staple length (!1 3/8 inch). 2,5 The production of ELS cotton as compared to Upland cotton is relatively small, making up just 3% of the world supply 8 and, consequently, saw ginning is the most prevalent gin technology in the world. [2][3][4][5][6][7]9 As the production of ELS cotton is eratic, decreasing and expensive, substituting ELS 1 CSIRO Manufacturing

Quarantine treatments of raw cotton fiber with gamma irradiation are known to have an adverse effect on fiber properties and thus could have an effect on processing into textile products. In this study, the effects of such irradiation treatments on two different cottons, cultivars of Upland and Extra Long Staple, were studied. Even at low dosages, gamma irradiation affects the physical properties of the fiber, with these effects becoming more apparent and significant as the dosage increased. While the affect on moisture regain was marginal, dye affinity was adversely affected. From a textile processing performance and quality point of view, the irradiation dosages did not have a significant impact on the yarn evenness and imperfection values, but did have a significant effect on yarn strength and elongation, as well as fabric strength and abrasion resistance. The degradation of these properties could have a significant to catastrophic effect on product durability.