asparagus diseases
Cercospora blight
Figure 1. Cercospora blight of asparagus. At a distance, symptoms manifest themselves as chlorotic ferns. 
Figure 2. Cercospora blight of asparagus. Note sunken roughly oval or round lesions. Close observations will reveal sporulation in the lesions. 
Figure 3. Cercospora blight of asparagus. Purple spot of Asparagus
Figure 1. Purple spot of asparagus. The lesions of this aptly named disease may be sunken. 
Figure 2. Purple spot of asparagus. 
Figure 3. Purple spot of asparagus. Rust of Asparagus
Figure 1. Rust of asparagus. 
Figure 2. Rust of asparagus. Note erumpent pustules on stem.