Verticillium wilt (Verticillium dahliae Kleb.) is a fungal disease that causes significant losses both in fiber yield and its quality traits in upland cotton (Gossypium hirsutum L.). Therefore, the following study aimed to determine the effect of verticillium wilt’s (VW) impact on lint production and fiber quality of nine upland cotton genotypes grown with Verticillium dahliae-infested and non-infested plants under greenhouse conditions. Based on disease ranking results, the lint yield and fiber quality parameters were significantly (P < 0.05) higher for the cultivars Bayraktar and Livzara than the genotype Alekberi under fungal pathogen (V. dahliae) infestation. Fiber quality traits bore considerable effects from VW infected plants as compared to healthy (H) plants. Fiber length decreased from 29.10 (H) to 26.0 (VW) in the cultivar Alekberi and 29.05 (H) to 26.4 (VW) with cultivar Ganja-110, however, was unchanged in the cultivars Livzara and Barakat. For micronaire, a slight increase emerged in some VW infected cultivars versus their healthy counterparts. For disease severity ranking based on intensity of vascular stem discoloration, the cultivars Livzara, Barakat, Ganja-114, and Bayraktar proved resistant to VW. The selection of cotton cultivars tolerant to V. dahliae infection with economically important traits needs further exploration.

Keywords: Upland cotton (Gossypium hirsutum L.), cultivars, verticillium wilt, lint production, fiber quality traits, disease ranking, fiber yield and quality losses

Key findings: Verticillium wilt disease considerably affects the fiber quality traits in upland cotton. A slight decrease in fiber uniformity, increase in micronaire, and nonsignificant differences for fiber elongation were notable in the diseased plants compared to healthy ones.