Pansy Diseases 311 



Anthracnose 



Caused by CoUetotrichum viola-tricoloris R. E. 

 Sm. 



Symptoms, The disease attacks the petals, and 

 affected flowers become deformed, and fail to pro- 

 duce seed. This is a serious consideration especially 

 from the seedman's point of view. The spots on 

 the leaves (fig. 62, a) are small with prominent 

 margins. 



The Organism. The acervuli are numerous, the 

 stroma poorly developed, and the setae mostly sin- 

 gle or in pairs, short, two septate and deep brown 

 in color. The conidiophores are short, the conidia 

 oblong or slightly curved, with blunt ends (fig. 62, 



b-f.). 



Control, The disease is usually introduced with 

 the seed. All shriveled seed should therefore be 

 discarded, and the healthy ones soaked for five min- 

 utes in a solution made of one ounce of formalde- 

 hyde in twenty gallons of water. Diseased plants 

 should be destroyed by fire. Pansy beds where 

 anthracnose is present should be kept on the dry 

 side of the house. The plants should not be 

 sprinkled with water, as in this way the spores of 

 the causal fungus may be spread about. Healthy 

 plants may be protected by spraying with a standard 

 fungicide. 



Leaf Spot 



Caused by Cercospora viola Sacc. 



Symptoms. This disease appears as small dead 



