3 88 



TEXTBOOK OF BOTANY 



crops in order to eliminate the disease. It has been found 

 that lime, ashes, and horse manure tend to increase the 

 growth of the fungus. Care must be taken to use only dis- 

 infected potatoes for planting. 



392. Peach Scab. This is a common and well-known 

 disease, found on almost all second- and third-grade peaches 



FIG. 222. A potato leaf at- 

 tacked by the early blight. 



FIG. 223. A bean plant inoculated 

 with the imperfect fungus which causes 

 anthracnose a disease which is at times 

 very serious, attacking the younger parts 

 of the stem, the leaves, and the pods. 



and apricots. It causes small, circular, dirty spots over 

 the greater portion of the fruit. If the spots are very nu- 

 merous, the skin of the fruit is likely to crack, making pos- 

 sible the entrance of decay-producing fungi. This disease 

 is often associated with the brown rot of the peach and some- 

 times causes equal loss to the grower. Leaves and twigs 

 may also become infected ; the fungus may continue to live 

 in the twigs for several years and so be a continual source of 

 spread of the disease. The means of control suggested for 



