4 Levi Otto Gratz 



the disease in the past. The last-named term is most frequently used in 

 western New York. These names are used rather than the term damping- 

 off, since diseased seedlings often do not topple over and may apparently 

 recover. In fact, plants with slight lesions, though undoubtedly per- 

 manently injured, are frequently planted in the held. None of these 

 terms appear to the writer to be sufficiently descriptive. Damping-off 

 is too general and applies to the early stage only. Black rot is already in 

 general use for the bacterial disease caused by Pseudemonas campestre 

 (Pammel) E. F. Smith. Black shank disease only partially conveys the 

 idea intended. Stem rot is inaccurate, as the stem may not exhibit a 

 pronounced rot, especially in the later stage of the disease. In view of 

 these facts the writer suggests the name wire stem. This is more desirable 

 since most of the plants are not killed outright by the primary attack, 

 but emerge with a characteristically tough, wiry stem (Plate I). This 

 name accurately conveys the idea suggested by the symptoms. 



The first definite reference to this disease was by Atkinson (1895). 

 He describes in detail the damping-off of seedlings of such plants as radishes 

 and lettuce, and states that " egg plants and cabbages as well as others 

 are known to be affected." He attributes this to a " sterile fungus " 

 now known as Corticium vagum B. & C. Duggar and Stewart (1901) 

 report the disease on cabbage seedlings from Cairo, Illinois, in 1898, and 

 also on cauliflower seedlings at Geneva, New York. They consider 

 Corticium vagum the causal organism. Fawcett (1909) observed the damp- 

 ing-off of cabbage seedlings in Florida, caused by this fungus. Six years 

 later Sherbakoff (1916) reported isolating the fungus from cabbage, 

 cauliflower, and other hosts in Florida, and during the following two years 

 he presented data concerning some phase of experimental work on damping- 

 off (1917, a and b). During the past few years the disease has been reported 

 from Washington, Utah, Missouri, Indiana, Ohio, Alabama, Louisiana, 

 Virginia, and probably several other States. 



ECONOMIC IMPORTANCE 



It is difficult to obtain definite information concerning the actual losses 

 caused by this disease. The occurrence and the severity of the disease 

 where early cabbage is grown are not uniform, thereby making estimates 

 of actual seedling losses impossible. A severe outbreak is especially 

 disastrous to the grower of large acreages because of the large number of 

 plants (approximately 10,000) required to plant an acre. A total or partial 

 loss of the seedlings with the season far advanced results in a reduced 

 acreage, as there is but slight possibility of obtaining enough seedlings 

 from neighboring growers to replace those that are killed. % To forestall 

 such an emergency a much larger number of seedlings are grown than 

 would otherwise be required. It is evident that this requires much addi- 

 tional time and greenhouse space. 



