Scientists Establish Link between Stink Bug, Cotton Disease

Scientists from the U.S Department of Agriculture’s Agricultural Research Service (ARS) have solved the mystery of a disease that can destroy up to 15 percent of a cotton crop in the southeastern United States. ARS says that the discovery could save cotton crops and prevent unnecessary insecticide spraying.

Ten years ago, scientists reported an emerging seed rot disease that was discoloring seeds and darkening fibers in cotton bolls in the southeastern states, making the crops unmarketable. Gino Medrano and colleagues from the ARS Cotton Pathology Research Unit discovered that this disease is caused by bacteria transmitted by the southern green stink bug (Nezara viridula). The stink bug’s bite, the scientists found, creates a pathway for the bacteria to enter the boll and damage it. By infecting bolls at various stages, they found damage levels depending on when infections occur in the fruiting cycle and on how long infection is allowed to spread before harvest. Bolls infected three weeks after flowering are resistant and undamaged. Younger bolls remain susceptible.

Read the full article at http://www.ars.usda.gov/is/pr/2009/090121.htm