Distribution and Severity of Alfalfa Pests 



Diseases 



I I Not known to occur or occurs but is not an 

 important problem 



I 1 Occasionally causes significant losses on 

 susceptible cultivars 



i 1 Frequently causes significant losses on 

 susceptible cultivars 



Figure 1. — Bacterial leaf spot, Xanthomonas alfalfae (Riker, 

 Jones & Davis) Dows. 



Figure 2. — Bacterial wilt, Corynebacterium insidiosum 

 (McCull.) H.L.Jens. 



Figure 3. — Anthracnose, Colletotrichum trifolii Bain. 



Figure 4.— Common leaf spot, Pseudopeziza medicaginis 

 (Lib.)Sacc. 



Figure 5. — Downy mildew, Peronospora trifoliorum d By. 



14 



