Sweet Pea Diseases 343 



Anthracnose 



Caused by Glomerella rufomaculans (B.) V. Sch. 

 and Sp. 



Symptoms, Like streak, anthracnose has not yet 

 made its appearance on greenhouse sweet peas. 

 Whether this is merely accidental, or whether indoor 

 conditions are unfavorable to the disease remains to 

 be discovered. It is necessary, however, that the 

 grower be familiar with the disease in order to pre- 

 vent its spread indoors. The symptoms of Anthrac- 

 nose are manifested in a wilting or dying of the tips, 

 which become whitish and brittle and readily break 

 off. At other times the wilt works downwards and 

 involves the entire branch. Frequently, also, leaves 

 thus infected become brittle and soon drop (fig. 

 70, a.). Examination of an infected leaf with a 

 hand lens shows that it is peppered with minute 

 salmon-colored pustules. At the time of blossoming 

 the fungus makes its attack on the peduncle, or the 

 fungus attacks both the flower bud and the peduncle, 

 in which case both dry up, although they do not fall 

 off. The most distinguishable symptoms of this 

 disease are on the seed pods. Infected pods lose 

 their green color, become shriveled, and are soon 

 covered with salmon-colored patches, which cannot 

 fail to attract attention. 



Organism, The cause of the anthracnose is the 

 fungus Glomerella rufomaculans. This fungus 

 causes also the bitter rot of apple and the ripe rot 

 of grapes. Cross inoculations have definitely proven 



