324 BULLETIN No. 189 [June, 



size of the shrunken area and the depth of the injury are proportionate to the 

 serious condition of the ulcer, as it may be termed. If the injury remains con- 

 fined to the superficial tissues, the plant will usually recover. It does sometimes 

 recover when the injury reaches the vascular tissue, but more frequently death 

 results when the trouble has progressed thus far." 



No further original work has been done on this disease since the 

 time of Atkinson, altho several of the southern experiment stations 

 have published bulletins on cotton diseases, including the sore shin 

 and seedling rot due to Rhizoctonia. 



- 

 Dianfhus 



R. Solani was isolated from diseased plants of Dianthus barbatus 

 (Newport Pink), during July, 1913, in the perennial garden of the 

 Station. This variety and Diawfhus barbatus (single mixed) were 

 much more susceptible to stem rot than were any of the other varieties 

 grown. In fact, practically every plant of these two varieties died 

 from stem rot during the summer. These varieties are more like the 

 carnation than any of the others, and when affected, the symptoms of 

 the disease were very similar to those of stem rot of carnation. The 

 first evidence of the disease was the pale green color of the leaves, 

 followed in many cases by a sudden wilting of the foliage. When 

 plants in this stage were pulled up, the bark readily sloughed off, 

 leaving the wood exposed. When plants in the later stages of the 

 disease were pulled up, the stem usually broke off at the surface of the 

 ground, exposing stringy tissue. 



During the same month, a disease of Dianthus sequeri and D. 

 plumarius was under observation. Diseased parts of these plants 

 yielded Rhizoctonia in every instance. In the case of D. sequeri the 

 fungus seemed to be living saprophytically among the numerous pros- 

 trate, bushy branches. The brown strands of the mycelium could be 

 plainly seen running thru the bushy mass of the plant. Only a few 

 plants died. Unlike the case of D. barbatus, there was no characteris- 

 tic sloughing off of the bark, but a more or less general rotting of the 

 whole stem, which left the tissues very dry and stringy. The attack 

 was not confined to the main stem, but affected any of the branches 

 which touched the ground. 



Most of the plants of D. plumarius, occupying a space about three 

 feet long, died from attacks of the fungus. The symptoms of the dis- 

 ,ease were very similar to those of D. sequeri, the rotting appearing 

 to extend gradually from one point thru the whole stem. As with D. 

 sequeri also, the bushy habit of the plant gave ample protection to the 

 fungus, and the radiating strands of the brown mycelium of Ehizoc- 

 tonia were visible to the naked eye. 



^ Duggar and Stewart 32 in 1900 found a badly diseased plot of 

 Dianthus barbatus in which 90 percent of the plants, in the course 

 of the season, died from stem rot due to Rhizoctonia. 



