Alabama Extension plant pathologists and crops specialists confirmed cotton leaf roll dwarf virus (Cotton Blue Disease or CLRDV-AL) in Alabama.
The disease — spread by aphids — damaged cotton in 2018 in counties along the Florida Panhandle. Extension will soon issue guidelines to manage CLRDV-AL as planting season begins.
Extension’s Austin Hagan said henbit, a common winter weed, tested positive for CLRDV-AL and is a likely host.
“Alabama cotton producers, particularly in counties along the Panhandle, should accelerate their winter weed control program in any remaining fields where cotton or peanuts will be grown in 2019,” Hagan said.
Researchers are sampling winter weeds and perennials to test for the virus. Many no-till and reduced-till fields have been sprayed for winter weeds. Experts advise a burn-down herbicide application to kill winter weeds.
As a result of mild winter weather and possible overwintering, disease onset may occur earlier than in 2018.