Brown spot damage caused by Alternaria tenuis increased during the yellowing phase of the flue-curing process. Increase in lesion number and in lesion area were influenced by duration and temperature of the yellowing period. The increase in lesion number was due to further development of small incipient lesions resulting from infection in the field. The progressive enlargement of necrotic tissue of existing lesions was the most serious facet of the increased damage. Weight loss during flue-curing of diseased tobacco leaves was approximately 3 percent greater than for disease-free leaves. Brown-spot-sensitive cultivar 'Coker 298' was damaged more than the tolerant line NC 8038-5-9. Varietal differences in lesion area and weight loss were attributed to the larger chlorotic halo surrounding existing lesions of the sensitive cultivar.

(Full article published with kind permission from "Tobacco International")