Verticillium wilt on-farm cotton cultivar variety evaluations, 2014

摘要

Eighteen cotton varieties were planted and evaluated for resistance to Verticillium dahliae. The trial was planted on the Tate farm in northern Alabama. Plots were six rows each, and approximately 500 feet long. The field was irrigated, when needed, with a drip tape irrigation system. Disease ratings were taken September 20. In 10 ft sections of the third row in each plot, total number of plants were determined, and stems were cut longitudinally to assess disease incidence. Disease severity ratings of foliar symptoms were evaluated on a scale from 1 to 5 with 1= no foliar wilting, 3= interveinal chlorosis and necrosis of the leaves, and 5=completely defoliated plants. Four replications, evenly spaced throughout the field of each variety were counted. Petioles were sampled from infected plants of each variety by re-isolating to confirm the presence of Verticillium dahliae by the presence of distinct morphological characteristics. The trial was harvested on 17 Oct. Analysis of variance was conductedusing SAS 9.3 (SAS Institute), and means were compared using Tukey-Kramer Honest Significant Difference (HSD) (a < .10).