Target spot, which is caused by the fungus Corynespora cassiicola, is an emerging disease in cotton in the Lower and Mid-South in the U.S. Phylogenetically, C. cassiicola isolates collected from cotton across the Lower South are distinct from those collected from other crops, particularly vegetables. This suggests that C. cassiicola isolates from cotton are either a recent introduction to the U.S. or has arisen from a mutation. Rainfall patterns along with variety selection and management inputs relating to yield potential influence the target spot risk in cotton. Greatest target spot-attributed defoliation and subsequent yield losses, which may exceed 300 pounds of lint per acre, have been recorded for an intensively managed, susceptible variety having a yield potential above 2.5 to 3 bales per acre.
Dr. Austin Hagan of Auburn University will discuss the results of a two-year study on developing integrated strategies for managing target spot in cotton. Topics that will be addressed in the webinar will include disease distribution, variety susceptibility and potential yield loss, efficacy of registered and candidate fungicides, fungicide application number, timing, methodology, and placement, as well as the influence of cotton cropping frequency, tillage practices, seeding rate, and planting date on disease development and cotton yield.
Presenter: Austin Hagan, Professor, Extension Plant Pathologist, Auburn University
Created by Rosemary Hallberg