1 82 Journal of Agricultural Research voi. v.no.4 



At the time the above series were being run, five series of similar 

 inoculations were made with a pure culture of Alternaria panax, the 

 necessary checks for each series being used. One hundred per cent of 

 infection was obtained with this fungus, the symptoms and lesions 

 resulting from the inoculation being in every case similar to and indis- 

 tinguishable from those obtained with the Alternaria-like fungus. 

 Plate XIII, figure i, shows a longitudinal section through one inoculated 

 root. 



In order to test further the pathogenicity of these fungi and to confirm 

 their identity, inoculations were made directly in the soil on roots to 

 which the tops were still attached. Six series were made with the 

 Alternaria-like fungus and five with Alkrnaria panax. The soil was 

 removed from around the crown of the roots and an incision was made 

 in the crown. Into this incision was placed the inoculating material 

 from pure cultures of the two fungi. Ninety-two per cent of infection 

 resulted from the Alternaria-like fungus and eighty-five per cent from 

 Alternaria panax. The symptoms and lesions were again characteristic 

 and similar in each case. 



Further inoculations were made on the tops by inoculating the leaves 

 with mycelium from pure cultures of both fungi. For some unexplain- 

 able reason, or owing to the plants having been sprayed with Bordeaux 

 mixture, no definite results were secured during the summer of 191 3. In 

 June, 1 91 4, the work was repeated. Typical leaf -spots of Alternaria 

 panax were produced in abundance with both fungi. Plate XIII, figure 2, 

 is a reproduction of a photograph of the lesions produced on ginseng leaves 

 with the species of Alternaria isolated from roots. Spores from these 

 spots were secured and examined. No differences could be noted. 



Reisolations were made from the inoculated roots and leaves, and a 

 fungus identical \rith the original one used for inoculating was obtained. 

 Numerous attempts to produce infection on the roots without pre- 

 viously injuring them gave only negative results. 



Inasmuch as these fungi show no cultural differences and as both are 

 able to infect the leaves and roots of the ginseng plant, the only conclu- 

 sion warranted by the data at our disposal is that they are identical. 

 This being the case, the blight problem confronting the ginseng grower 

 becomes more complicated. Heretofore it has not been supposed that 

 Alternaria panax is able to cause a rot of the root. 



The above facts warrant the ginseng grower in taking other means 

 besides spraying in the control of this disease. The means recommended, 

 in addition to spraying, are (i) care in transplanting so as to injure the 

 roots as little as possible, (2) the removal of all tops and stems in the 

 fall, and (3) where the crowns of the roots are sufficiently deep below the 

 surface of the soil, burning over the surface of the bed with a thin layer 

 of straw after the tops have been removed. 



