Unexpected rainfall in harvest season has a detrimental effect on cotton lint color grade and germination rate to extent that economic losses occur for farmers, seed producers and manufacturers. This study was conducted to elucidate the effects of different rainfall amounts on cotton and to evaluate the response of different cultivars in the harvest season of 2014 and 2015. Bolls were exposed to 0 (control), 20, 35, 65, 95 and 125 mm of precipitation. The effects of rainfall were determined in GSN-24, Claudia, Gloria, ST-373, Flash, Carisma and ST-468 cotton cultivars (Gossypium hirsutum L.). The responses of cultivars to different cumulative rainfall were significant for lint color grade and seed germination rate. The linear curve in the decreasing direction according to the highest R2 value was evaluated for germination rate, reflectance (Rd), trash count and size whereas the polynomial curve was more likely for yellowness (+b). The effects of rainfall amounts on all observed characters were unfavorable. The different responses of cultivars were indicated that the cultivars with the least loss for lint color grade and seed production could be recommended in terms of highly profitable.

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High-quality cotton fiber has an important role in the textile industry. The regional differences due to environmental factors, genotype and cultural management lead to variation in fiber characteristics. A two-year field experiment was conducted to reveal the intra-regional differences in the Aegean region. The samples from Great Meander, Little Meander, Bakırçay, Gediz and Söke basins were analyzed by High Volume Instrument (HVI) for fiber length (mm), fiber fineness (mic.), fiber strength (g tex-1), reflectance (Rd), yellowness (+b) and trash count (number per unit area) in 2019 and 2020. Range was 29.82-30.77 mm for fiber length; 4.62-5.09 mic. for fiber fineness; 31.26-33.36 g tex-1 for fiber strength; 69.62-71.0 for reflectance; 7.70-9.12 for yellowness and 56.04-101.48 for trash count. Although all fiber quality parameters were within the commercial limits, the higher quality fibers were produced in Little Meander and Söke basins in 2019. It was concluded that the main important differences among growing areas of the Aegean region might be in terms of trash count.

Pre-harvest precipitation in some years in many cotton-growing regions may adversely affect cotton yield and quality. The effect of carpel characters of cultivars on fall out (ground losses) and free fatty acid of seed under different precipitation amounts were investigated. The experiment was arranged in a two-factor Randomized Complete Block Design with four replications. The precipitation x cultivar interaction for carpel depth, free acid content and fall out were significant. Fall out values were between 38.9 kg ha-1 at 20 mm precipitation and 234.2 kg ha-1 at 125 mm precipitation. The amount of fall out in all varieties was negatively affected by the increase in precipitation. Gloria cultivar with a wide carpel had the lowest yield losses on the ground.