140 DISEASES OF THE SWEET PEA 



(fig . 25) makes its appearance in the 

 orchard. The fungus is carried over win- 

 ter on cankered limbs and mummied fruits 

 of diseased apples or on the diseased pods 

 of the sweet pea as well as in the soil. 



Mode of Infection and Period of In- 

 cubation. The anthracnose of the sweet 

 pea is mainly a disease of the tender parts 

 of the plant. Infection usually starts first 

 at the tips, although, as previously shown, 

 the fungus may attack the older parts of 

 the plant once they have been injured by 

 green Aphids or by red spiders. The 

 spores of the parasite usually germinate in 

 from six to twenty-four hours, according 

 to the amount of moisture present. The 

 germ tubes enter the host by breaking 

 through the epidermal cells of either leaf 

 or stem. 



The period of incubation varies from 

 three to five days, according to the amount 



