Target Spot in Cotton – How to identify it and management options

by Heather Marie Kelly, Extension Plant Pathologist, University of Tennessee

As cotton gets closer to blooming, scouts should be on the lookout for target spot and defoliation starting in the lower canopy.

The warm, wet weather the Mid-South has been experiencing could promote target spot in cotton fields, especially those fields that saw the disease in 2016 and are irrigated. Additional factors that increase target spot risk include higher planting rates, excessive N rates, narrow row spacing, vigorous growth, as well as hot, humid weather. Some facts about target spot: Continue reading

Tune in February 27 to learn how to manage target spot

In a webinar on Monday, February 27, at 3 PM Eastern, Austin Hagan, professor and extension plant pathologist at Auburn University, will discuss ways to recognize target spot in your field as well as management techniques to lower the risk.

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. Continue reading

Webinar: Managing target spot in cotton: results of a USDA NIFA-funded study

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. Continue reading

Don’t plant cotton in same place if you had target spot

In Delta Farm Press

Odds are that if you observed symptoms of target spot or Corynespora cassiicola in your cotton this year you’re probably going to see it again if you plant cotton in that field next year.

That’s the advice Heather Kelly, an assistant professor in field crops plant pathology at the University of Tennessee Institute of Agriculture, gave farmers attending the 2016 Cotton Tour at the West Tennessee Research and Education Center in Jackson. Continue reading