Host: flue-cured tobacco (Nicotiana tabacum (flue-cured type)
Description: Soon after exposure to high levels of atmospheric pollutants, leaves may develop dark green water-soaked spots about 1/10 inch in diameter. Within hours, the spots turn dark brown, sometimes remain brown, but often turn white within 48 hours. Symptoms occur most often in low areas of fields. Plants are most sensitive when growing rapidly (plant bed and 4-6 weeks after transplanting), but symptoms may appear at any stage of growth. In the plant bed or on very sensitive varieties, spots appear over the entire leaf surface but are usually confined to the leaf tips of less sensitive varieties. Occasionally spots coalesce, or a central spot may be surrounded by smaller ones. Weather fleck is often confused with other flecks caused by chemicals, diseases, or nutritional disorders.
Image type: Field
Image location: United States
Name: R.J. Reynolds Tobacco Company Slide Set
Organization: R.J. Reynolds Tobacco Company
Country: United States