312 



BULLETIN No. 189 



[June, 



bud. Other aster plants set in new soil at the same time that these 

 were transplanted developed normally with no stem rot whatever. 



TABLE 2. MORTALITY OF DIFFERENT VARIETIES OF ASTER GROWN IN OLD CARNA- 

 TION SOIL INFECTED WITH Rhizoctonia Solani 



As can be seen from Table 2, plants from all but two of the varie- 

 ties died in the bench. The varieties Azure Blue, Purple, and Pure 

 White were planted where most of the stem rot on the carnations oc- 

 curred ; hence the higher number of diseased plants in those varieties 

 is due to location rather than to varietal susceptibility to Rhizoctonia. 



Obviously the Rhizoctonia causing carnation stem rot was in this 

 case able to attack healthy aster plants. The stem rot of these plants 

 was typical and very similar to the rot of carnations. The first sign 

 of the disease was a yellowing and drooping of the foliage, followed, 

 sooner or later, depending on weather conditions, by a sudden wilt- 

 ing of the whole plant. When the plant was pulled, the bark of the 

 stem near the surface of the soil would slough off, leaving only the dis- 

 colored woody tissues. 



A stem rot of aster due to Rhizoctonia has been reported only once 

 before in this country. Duggar and Stewart 32 in 1901 found the my- 

 celium in the tissues of aster and later isolated a pure culture from 

 them. They observed the disease in a number of localities in New 

 York during that summer. 



BEAN, PJiaseolus vulgaris 



The damping-off of young bean seedlings by 7?. Solani, which 

 has been observed in the greenhouse and in the field, is characterized 

 by the production of small lesions at the surface of the ground either 

 on one side of the stem or girdling it, followed by the falling over and 

 death of the seedling. 



When the fungus attacks older bean plants, lesions of various 

 sizes are produced just below the surface of the ground, at the surface, 

 or one or two inches above it. In some plants these discolored spots 

 can be found on the larger roots also. The lesions, as a rule, have a 



