late blight of potato

Late blight of potato-I have little experience with this disease. In fact, the photos below are scanned from 35 mm slides. 

Figure 1. View of potato field with late blight. Figure 1. View of potato field with late blight.
Figure 2. Lesion on leaf caused by late blight of potato. Figure 2. Lesion on leaf caused by late blight of potato.
Figure 3. Lesion on leaf caused by late blight of potato. Figure 3. Lesion on leaf caused by late blight of potato.
Figure 4. Lesion on leaf caused by late blight of potato. Figure 4. Lesion on leaf caused by late blight of potato.