24 U. S. DEPARTMENT OF AGRICULTURE. 



ASPARAGUS: SLIMY SOFT ROT; BACTERIAL ROT. 



(See Slimy Soft Rot). 



ASPARAGUS: WATERY SOFT ROT; SCLEROTINIA ROT. 



(See Watery Soft Rot) . 



BEAN: ANTHRACNOSE. 



Cause: A fungus (Colletotrichum lindemuthianum). 



Anthracnose is marked in the very early stages by minute 

 oval or circular spots which are maroon to reddish in color. 

 These spots are not water-soaked as in the bacterial blight. 

 They form ulcer-like lesions, which increase rapidly in size 

 and, though circular, often coalesce to form large irregular 

 spots. Very soon, often in 24 hours, the spot becomes darker 

 in color, the central tissue dries up and shrinks, and a de- 

 pressed, considerably sunken spot results, with a black 

 center and generally a reddish border. Under moist con- 

 ditions the dark center of the spot becomes covered with 

 orange-pink dots or spore heaps which may run together 

 and form a slimy layer. These spore heaps are borne on 

 cushions known as acervuli (singular, acervulus). The bor- 

 der of the lesion is sharply marked, especially on the wax 

 pod varieties. 



From pod lesions the fungus often enters the seeds. In 

 case of light attack the seed shows only a yellowish spot. 

 In severe cases the spots are yellowish, brownish, or black, 

 and circular or irregular in shape, and are surrounded by a 

 reddish zone. They may be sunken, but rarely show the 

 pinkish slime noted on the pod spots. The spots on the seed 

 are darker colored and more definitely marked than those 

 of bacterial blight. 



Anthracnose occurs in all varieties of wax pod, green pod, 

 pole, navy, kidney, lima, and some scarlet runner beans. Its 

 development is favored by moderately cool weather, and its 

 spread, by wet weather. Since it is carried in the seed, the 

 disease may occur in any bean-growing section, but the 

 regions subject to cool, wet weather are most seriously af- 

 fected. It is least prevalent in the Rocky Mountain and 

 Pacific Coast States. 



The original infection takes place in the field where both 

 the vines and pods are affected. The disease develops on 

 the pods in transit, and may spread under very moist con- 

 ditions. 



Crop rotation and the use of disease-free seed or disease- 

 escaping varieties are the only known effective control 

 measures. Seed grown in hot, dry regions is comparatively 

 free from anthracnose. 



Ref. (76); (14); (47). 



BEAN: BACTERIAL BLIGHT. 



Cause: Bacteria (Pseudomonas phaseoli). 



In the early stages bacterial blight is marked by small, 



