Effects of production practices on temporal disease progress of Verticillium wilt of cotton (Gossypium hirsutum L.) in the Texas High Plains, USA

Abstract

Verticillium wilt of cotton (Gossypium hirsutum L.), caused by the soilborne fungus Verticillium dahliae Kleb., is an economically damaging disease. To date, limited information is available regarding the effects of common production practices on the epidemiology of Verticillium wilt of cotton. Therefore, this study evaluated the effectiveness of different seeding rates and cotton cultivars on suppressing Verticillium wilt and simulate the temporal dynamics of Verticillium wilt in cotton. Field experiments were conducted in 2015 and 2016 at two locations naturally infested with V. dahliae in the Texas High Plains. Results indicated wilt incidence decreased significantly up to 49% when planting partially resistant cotton cultivars at higher seeding rates (9.8–19.5 seeds m−2) at both locations across years (P < 0.05). The area under disease progress curves (AUDPC) increased significantly as seeding rate decreased, and the partially resistant cultivar FiberMax 2484B2F showed a significantly lower AUDPC compared to the susceptible cultivar Deltapine 1212B2RF. Reductions in lint yields by Verticillium wilt, particularly under high disease pressure, could reach 1.03 tons ha−1 (P < 0.05). FiberMax 2484B2F remained significantly lower wilt incidence (23%) than the susceptible cultivar. When characterizing temporal disease progress, nonlinear Gompertz, logistic, and exponential models had better statistical fit (R2) than the linear model (P < 0.05). Under high disease pressure in 2016, the R2 values (0.94 and 0.97 at Quaker and Cone) of the Gompertz model were significantly greater than others. The Gompertz was determined to be the optimal fitting model for simulating the Verticillium wilt epidemics.