Comparing cotton fiber quality from conventional and round module harvesting methods

Abstract

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.

Cotton and fiber quality in function of picker harvest speed

“…Longer fibers are preferred, because they are stronger and thinner with spinning; therefore, analysis of the average length of the upper-half of the fiber is important for the commercialization of the lot. In contrast to the present study, Sluijs et al (2015) obtained a mean value of 30.6 mm, which refers to the "long" classification.…”

“…When the breakage strength of fibers was analyzed according to ASTM D 1445, the mean value between the speeds was 29.12 and was thus classified as high (27.0-29.0). This classification was different from that obtained by Sluijs et al (2015), with a mean value of 30.25, falling into the "very high" classification for values exceeding 30.00.…”

“…According to the American Society for Testing and Materials (ASTM D) 1448-79, the results obtained for the micronaire index with all treatments were regular or medium (4.0 to 4.9), at 4.6. This classification was also obtained by Sluijs et al (2015), with mean value of 4.16. Sui et al (2010) concluded that the micronaire value is lower following mechanized harvest than with manual harvest, as the machine also harvests the immature lint and impurities (mainly leaves and stem parts).…”

The effect of seed cotton moisture during harvesting on – part 1 – fiber quality

“…17,18,28 It is likely that the airflow measurement of micronaire was effected by the higher trash and dust levels of the seed cotton harvested at a moisture level of >12%, as reported in previous studies. 67–69…”

Experimental Study and Simulation of the Stress Relaxation Characteristics of Machine-Harvested Seed Cotton

“…However, because the integration rate of cotton pickers in China is low, machine-harvested seed cotton requires secondary processing, resulting in its expensive costs of storage and transportation [7,8]. Therefore, machine-harvested seed cotton is compressed into modules of certain shapes, sizes, and densities before storing and transporting them [9]. Advanced cotton pickers have integrated compression molding equipment with cotton pickers, which can make mechanical harvest and compression molding continuous, solving the problems effectively [10,11].…”