244 



VEGETABLE GARDENING 



be of the best quality because this will vaporize without 

 any residue. The vapor of this substance is very in- 

 flammable and the work should, therefore, be done at a 

 distance from other buildings and no light of any kind 

 be brought near." 



317. Anthracnose (Colletotrichum lagenarium) is the 

 most common and the most destructive of the bean dis- 

 eases. It is a fungous disease, which attacks all parts 

 of the plant except the roots. Diseased seed is often 

 the source of the malady. The young 

 tender stems may become affected and 

 the plants killed when conditions are 

 favorable for the parasite; or it some- 

 times appears later on the pods, as well 

 as on other parts of the plant. The 

 disease is very noticeable on the yellow 

 pods of wax varieties, which they reduce 

 in value or render unfit for market pur- 

 poses. Figure 62 illustrates the dis- 

 eased pods. The Cornell Station (Cor- 

 nell Station Bulletin 255, p. 436) makes 

 the following statement in regard to 

 this disease: "The spots or cankers are 

 black with reddish or yellowish mar- 

 gins. Most growers are also familiar 

 with the disease on the seed itself, espe- 

 cially on the white beans, where it makes rusty, red spots 

 of various sizes, sometimes involving nearly the entire seed, 

 though ordinarily only producing a slight discoloration 

 on one side. The disease enters the seed by way of the 

 pod, the fungus penetrating from the outside into the 

 young and tender seed. . . . When the diseased 

 seeds are planted in the soil, and first come through the 

 ground, they are sure to show the small black cankers 

 on the cotyledons or seed leaves and a little later on the 

 stems," 



FIG. 62. BEAN 

 ANTHRACNOSE 



