Screening for Cotton Resistance to Corynespora Cassiicola

Target spot (Corynespora cassiicola) causes economically significant decreases in yield across cotton grown in the southeast. Resistant varieties have not been identified so it is critical that a screening protocol is developed to unearth such varieties. It is imperative that this procedure be swift and replicable which is why mist chamber screening on the first true leaf stage is favored. By using a mist chamber, optimal environmental conditions for target spot can be mimicked and young plants that otherwise would be unlikely to show symptoms of disease in the field, will develop lesions. Visual scoring and imagery analysis through sigma scan will permit discerning differences in severity among the 2017 regional breeders testing network (RBTN) varieties. The subsequent data will be compared to RBTN field ratings to determine if the mist chamber screening correlates with what is observed in the field. If there is a trustworthy correlation, a wide range of germplasm will be screened.