Determination of fiber technological properties and the reactions of some cotton genotypes against wilt disease (Verticillium dahliae Kleb.)

The trial established at a field known to be contaminated with cotton wilt disease (Verticillium dahliae Kleb.) as randomized block design with 3 replications in April 2018 in in the research area of Dicle University Faculty of Agriculture. The study was performed on 15 cotton genotypes (Gloria, Carla, Candia, Babylon, ST-498, MAY 455, MAY 555, BA-119, BA-440, Edessa, ADN-123, DP-499, Berke, ES-4, ES- 5) to determine the reactions against wilt disease and the technological properties of fiber. Disease assessment was made in two separate periods. The first, when boll opening period of 50-60 % on the 0-4 scale according to the leaf symptoms. The second, made according to 0-3 scala considering the color change of the stem section after the harvest. As a result, disease severity and disease rate of genotypes were determined. The fiber yield and 100 seed weights of the genotypes were obtained by weighing on the precision balance (0.01 g) after ginning. In addition, the analysis of the fiber technological properties (fiber fineness, fiber length, fiber strength, spinning index, short fiber index, elongation percentage of elongation, uniformity, brightness, yellowness, trash ratio, trash number) of these genotypes were performed using the 'HVI 1000 Spectrum Device'. As a result, the lowest trunk cross-sectional disease severity was found in DP-499 (0.88) genotype. Berke (2.08) genotype showed the highest disease severity, followed by MAY-555 (1.91) and Gloria (1.88) varieties, respectively. Disease severity in all other genotypes was among the values given above. Although there was a statistical difference between cotton genotypes in terms of fiber fineness, fiber length, uniformity, fiber gloss, yellowness, strength, percentage of elongation, spinning index and short fiber index, while had no difference in trash ratio and trash number. In the relationship between disease and fiber technological properties; a significant positive correlation (P <0.05) was found between wilt disease and short fiber index. On the contrary, a significant negative correlation (P <0.05) was found between the disease's elongation percentage and the spinning index, the disease and fiber strength.