Incidence of Verticillium wilt and yield losses of cotton cultivars (Gossypium hirsutum) based on soil inoculum density of Verticillium dahliae

Inoculum density (propagules per gram of soil) of Verticillium dahliae at planting time, when plotted against the disease incidence (percent foliar symptoms) for two cotton cultivars for three successive years, closely followed the negative exponential curve Y=57.09 * (1-e -0.351*χ ). Correlation coefficients for each of the 3 yr separately and all 3 yr cumulatively were 0.71, 0.96, 0.84, and 0.85, respectively []