asparagus diseases

Cercospora blight

Cercospora blight-Initial symptoms on ferns may be the chlorotic and necrotic lesions on stems. Closer observations will reveal the light oval lesions with darker margins. The causal fungus may be observed in the center of lesions (in structures known as stomata) under appropriate conditions. 
Figure 1. Cercospora blight of asparagus. At a distance, symptoms manifest themselves as chlorotic ferns. 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 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. Figure 3. Cercospora blight of asparagus.

Purple spot of Asparagus

Purple spot-spears may appear as a pink or purple mottle. Lesions may have light necrotic centers. 
Figure 1. Purple spot of asparagus. The lesions of this aptly named disease may be sunken. Figure 1. Purple spot of asparagus. The lesions of this aptly named disease may be sunken.
Figure 2. Purple spot of asparagus. Figure 2. Purple spot of asparagus.
Figure 3. Purple spot of asparagus. Figure 3. Purple spot of asparagus.

Rust of Asparagus

Rust-Erumpent pustules appear dark. Ferns may appear necrotic and unthrifty. 
Figure 1. Rust of asparagus. Figure 1. Rust of asparagus.
Figure 2. Rust of asparagus. Note erumpent pustules on stem. Figure 2. Rust of asparagus. Note erumpent pustules on stem.