Comparison of Fiber Quality Properties of Different Cotton (G. hirsutum L.) Varieties for Normal and Late Harvest Periods

: 8 Cotton fibers are the most important raw material of the textile industry. Clean collection of cotton 9 fibers increases the quality of textile products and the market prices. This study was conducted to 10 investigate the effects of normal and late harvest period of different cotton varieties on cotton fiber 11 and yarn properties. The quality properties of the fibers were determined with the HVI device, and 12 the quality properties of the yarns obtained from the fibers were determined with the USTER 13 TESTER device. The fiber quality properties such as fiber fineness (micronaire), fiber maturity, 14 fiber length (UHML, mm), strength (g/tex), brightness/whiteness (Rd), and yarn quality properties 15 such as yarn evenness (%), thin places, neps+200 (%) and hairiness were investigated in the study. 16 The exposure of fibers to rain during the harvest period of 2018 caused a decrease in the quality 17 properties. Inability of the plants to receive sufficient sunlight during the last physiological 18 development period caused a decrease in photosynthesis rate. This negative situation negatively 19 affected the physical quality properties of fiber and yarn. The results indicated that the physical 20 quality properties of fibers and yarns obtained in 2019 were higher than those in 2018. The aim of 21 this study was to determine the effect of late harvest period on fiber and yarn quality properties and 22 thus on quality of textile products. In addition, the study was carried out to guide researchers who 23 will conduct researchers on similar topics.

The reports of ICAC for 2018-2019 indicated that Turkey ranked the ninth country in the world 36 cotton cultivation, fifth in cotton yield per unit area, eighth in cotton production; fourth in cotton 37 consumption and fourth in cotton import (Anonymous, 2020).

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Harvest time is one of the most important issues in cotton agriculture. The harvest time has a 39 significant effect on the amount of fiber per unit area and on the fiber quality properties. Delay in 40 harvest due to ecological and environmental factors or planning causes in quality losses. The 41 ripening of bolls is one of the important factors that determine the harvest time.

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The parameters related to the yield and quality characteristics of cotton vary depending on the 43 genetic structure of the variety used, the maintenance carried out by the producers and the

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Micronaire (fiber fineness), which is a measure of fiber fineness and maturity, is the major fiber 49 quality property of cotton. Micronaire is an important feature of cotton fiber quality that affects 50 spinning and dyeing processes.

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The increase in the monthly average rainfall, and the length of the average rainfall period in autumn 52 negatively affect the fiber quality. Especially in the early autumn months, rainfalls coincide with the 53 harvest period are a serious risk on fiber quality properties (Luo et al., 2016).

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Quality cotton fiber is vital to produce quality yarn and therefore higher quality fabrics. HVI and 55 AFIS fiber testing equipment, which are the state of the art of Uster are the devices used in testing 56 cotton fiber properties. Understanding the properties of cotton fibers and their relationship to yarn 57 and fabric quality are essential to produce quality textiles products. Cotton fiber quality is 58 determined by various parameters such as maturity, fineness, length, strength and uniformity. Better

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Harvest time directly or indirectly affects fiber yield, physical fiber quality properties, and chemical 65 structure of fiber and textile product quality. Cotton harvest is carried out manually or using 66 machine. Although the harvesting methods are different, the delay in the harvest time causes some biosynthesis, loosening and expansion (Cosgrove, 2005, Kang et al., 2019. Cell walls define the 82 shape of plant cells, controlling the extent and direction of cell elongation and thus the growth of 83 organs. The main carrier component of plant cell walls is cellulose, which is collected in the Golgi 84 apparatus and then synthesized by cellulose synthase complexes (Polko, 2019). The fiber cells of 85 cotton seeds on the epidermis layer are the most important agricultural textile product in the world.

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Four different stages of fiber development, consisting of initiation, elongation, secondary cell wall 87 biosynthesis and maturation, which last approximately 2 months, are required to produce fully 88 mature fibers (Kim, 2015).   Table 1 • Prolonged rainfall occurred during the harvest season. • October and November, which are the cotton harvest months, were rainy. • The harvest was carried out in March 2019.
• The cotton harvest was carried out at the beginning of October, which is the usual harvest time, as the weather conditions during the harvest period was as expected in that season.

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All necessary agricultural practices from sowing to the harvest were fully implemented.

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Conventional practices which have been used in the Harran plain were used in cotton cultivation.

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The cotton harvest was carried out by machine, and the cotton obtained at the harvest was processed 121 with a 30 Ne (yarn number) combed tricot ring spinning machine.

Method: 123
The quality characteristics of 4 different fibers obtained from 4 different cotton varieties produced 124 in 2018 (late harvest period) and 2019 (normal harvest period) were determined using the HVI 125 device. Fiber physical quality properties determined by using the HVI device were fiber fineness 126 (micronaire), fiber maturity, fiber length (UHML, mm), strength (g/tex), and brightness/whiteness 127 degree (Rd). The unevenness, fine places, nep and hairiness properties of 30 Ne 100% cotton yarns 128 obtained from four different cotton fibers were determined using the Uster Tester.

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The data obtained were subjected to analysis of variance (ANOVA) according to the splitted plots

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The results showed that the fiber maturity was not fully realized in the early harvest, whereas the 155 seed cotton was affected by the adverse weather conditions such as rain and wind in the late harvest.                 The difference between the mean in the same letter group are not statistically significant. ns: not significant. *: Important at 294 5% level of significance; **: Important at 1% level of significance.

Yarn Unevenness (%): 297
The effects of cotton variety and the interaction of variety x harvest time on yarn evenness were not 298 statistically significant. However, the evenness of yarns obtained from different cotton varieties at 299 different harvest times was significantly different (p<0.01) ( Table 8). The lowest yarn evenness 300 value was recorded in normal harvest time (9.06%), while the highest yarn evenness value was 301 measured in late harvest time (9.24%). Ayele (2017) stated that fiber fineness affects yarn 302 irregularity. Similarly, Kelly et al. (2015) reported that longer, stronger and thinner fibers provide 303 higher spinning. The researchers indicated that the spinning will be excellent when the smoothness 304 of the yarns is high as the speeds in the drafting section will be well controlled, however, the yarn 305 irregularity increases when the short fiber content is high. Higher smoothness of yarns with the 306 transformation of long fibers into yarn confirms our results. The results of this study showed that 307 delay of harvest and exposure of fibers to rain for a long time negatively affected fiber length, 308 strength and fineness properties and increased hairiness. The difference between the mean in the same letter group are not statistically significant. ns: not significant. *: Important at 313 5% level of significance; **: Important at 1% level of significance.

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thin places determined in different harvest time were significantly (p<0.01) different from each other 318 (Table 9). The lowest thin places (-40%) value was recorded in normal harvest period (14.51). The 319 highest thin place value was recorded in late harvest period (17.51). The fibers are exposed to rain

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These factors lead to a decrease in the fiber quality properties of cotton and an increase in the 355 neps+200 ratio. The increase in neps ratio of cotton and yarn causes a decrease in many quality produced from cotton obtained at the beginning of the harvest season compared to cotton obtained 360 at the end of the harvest season in the same field. The neps not only affect the appearance of cotton 361 yarns and fabric, but also often lead to lower yarn strength, spinning ends down and low uniform 362 yarn production (Van der Sluij and Hunter 2016). 363

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The lowest yarn hairiness value was obtained in normal harvest period (1.50%), while the highest 371 yarn hairiness value was determined in late harvest period (1.62%) ( Table 11). The delay in harvest 372 time caused an increase in yarn hairiness. The delay in harvest of the cotton that reaches harvest 373 maturity negatively affects the fiber quality properties. This situation causes various quality 374 problems in yarn, fabric woven from yarn and final textile products. Backe (1996) reported that the 375 fiber length of three cotton blends representing low, medium and high elongation of cotton fiber 376 affects yarn hairiness. Our findings that the fibers lengths obtained in the late harvest are low and 377 the hairiness is high are similar to the findings of Backe (1996). The findings of El Mogahzy and 378 Chewning (2001) that fiber length can affect CV% and hairiness of yarn are similar to our findings 379 that late harvest will affect fiber length and hence hairiness.