152 



Diseases of Economic Plants 



stem. It develops late in the season. The name Leopard- 

 spot is strikingly suggestive for another disease that produces 

 long, irregular spots, ashen in color, with 

 dark borders. No treatment is known. 



BEAN ^-^^ 



Pod-spot anthracnose ^^^-i^"- '^^- '^^ 

 {Colletotrichum lindemuthianum (S. & 

 M.) B. & C). — First described in 1878 

 in Germany, this disease is widely 

 known and is especially destructive. It 

 develops so rapidly that beans delivered 

 to the cars for shipment in apparently 

 healthy condition may, upon arrival at 

 their destination, be quite badly spotted. 

 The loss is often 20 per cent, and occa- 

 sionally a total loss is reported. Upon 

 the pods the disease appears as dark- 

 colored spots, usually sunken, varying 

 in size from 1-10 mm., or more if sev- 

 eral spots coalesce. The border of 

 the spot is often tinged with red, 

 the center rust-colored. Old pod -spots 

 overlying seeds within cause spots 

 upon these seeds. The pod-spots are 

 much more noticeable and unsightly 

 upon light-colored than upon green 

 beans. 



Similar spots are found upon the 

 stems and leaves. They are especially 

 noticeable upon young stems still 

 blanched and upon the seed leaves. On 

 Fig. 80.— Anthracnose older leaves they may appear upon the 



spots upon bean pods, ^^j^s, blackening and killing them and 



After btewart. , , , j. 



the lear. 



The wax varieties are especially susceptible, while lima 



beans are quite resistant. The Well's Red Kidney also 



