516 Journal of Agricultural Research vol. xx.No. 7 



OCCURRENCE OF THE DISEASE 



In the summer of 191 6 the disease was found only on the plantation of 

 Mr. James H. Boiling near Benedict, Charles Co., Md. It was serious in 

 only one field of about 6 acres on this farm, where perhaps 10 to 20 per 

 cent of the plants were dead or showed symptoms of the disease, although 

 in smaller areas in the field it is estimated that 50 to 75 per cent of the 

 plants were damaged (PI. 63, A). According to Mr. Boiling and the 

 tenant on the farm this disease had occurred at intervals for many years 

 on this farm but not so seriously as in 1916. 



During the summer of 19 17 Charles County was again visted, with the 

 result that the disease was found on two other farms near Newport, Md. 

 The disease was not apparently so serious this season as in the previous 

 one. This region was not visited during the seasons of 191 8 and 1919, 

 and nothing further is known of the disease in that section. 



In the summer of 191 9 a "new" disease of tobacco was called to the 

 writer's attention by correspondence from Clermont Co., Ohio, and speci- 

 mens were received through the courtesy of Mr. David Geesner of Owens- 

 ville on September 20, which showed typical symptoms of Fusarium-wilt 

 on mature plants of the White Burley variety. Sixty-six pieces 

 from diseased portions were plated out, practically all of which yielded 

 Fusarium, from which artificial infection was later secured. The disease 

 is also said to have occurred previously in the vicinity of Owensville. 



The symptoms of the disease are so evident that growers could not 

 fail to note and report its occurrence. On account of the scarcity of 

 such reports either from the farmers or experiment station workers in 

 the tobacco-growing regions outside of the Granville (bacterial) wilt areas 

 it is believed that the Fusarium-wilt is not a serious disease and probably 

 will never become of great economic importance. If, however, it becomes 

 more generally introduced into the White Burley districts it may become 

 a serious parasite, since this variety, as will be shown, is very suscepti- 

 ble to the wilt. 1 In North and South Carolina, Georgia, and Florida 

 where the Granville wilt occurs, it is possible that the Fusarium-wilt is 

 also present, but growers as well as plant pathologists would be likely to 

 report such cases as Granville wilt unless a special examination of the 

 diseased tissue were made. It is not believed that there is much danger 

 that this disease will become serious in the northern cigar tobacco growing 

 regions on account of the resistance of the varieties grown and the climatic 

 conditions prevailing. 



REVIEW OF THE LITERATURE 



The occurrence of Fusarium-wilt diseases of a considerable number of 

 plants are now reported in literature. The Fusarium-wilt of tobacco 

 possesses much in common with these diseases in that it is a vascular 

 disease. However, it is not proposed here to enter into a review and 



1 During the summer of 1920 specimens of Fusarium-wilt were received from the White Burley dis- 

 trict of Kentucky. 



