A. S. HoRNR 197 



Fusarium disease. 



Two types of Fusarium disease are recognised by Orton'. The 

 first, Fusarium wilt, caused by Fusarium oxysporium described by 

 Smith and Swingle in 1901, affects the field crop and is one of the most 

 serious diseases of the potato with which the United States has to deal. 

 According to Orton, there is no evidence that the Fusarium wilt occurs 

 in Europe. Wollenwcber^ has been able to differentiate the Fusarium 

 oxysporium of Smith and Swingle from other potato Fusaria and finds 

 it to be distinct from any European form. The second or dry rot 

 disease, according to WoUenweber's investigations, appears to be caused 

 by one or more species of Fusarium. The dry rot Fusaria do not, as 

 a rule, attack the tubers when in the soil, although they are certainly 

 present there as shown by Miss Dale^, who includes F. solani in the 

 fungus flora obtained by her from sandy soils. Miss S. Longman^ 

 records that Fusarium solani attacked the potato plant in experimental 

 plots at Reading in 1909, but cases appear to be of rare occurrence in 

 Britain. 



Fusarium becomes evident in the potato pit or store especially 

 when potatoes are stored in a damp condition, a state of affairs often 

 difficult to avoid in some potato-growling districts. A crop that has 

 been attacked by Phytophthora or sprain is especially liable to suffer. 



The question of the parasitism of Fusarium. solani was fully discussed 

 by Pethybridge and Bowers^ in 1908. These authors state it is quite 

 clear that the fungus is a true parasite capable of directly producing 

 the disease in absolutely healthy potato tubers. The disease can be 

 communicated therefore to healthy tubers in contact with diseased ones. 

 A similar conclusion was arrived at by Miss Longman. 



Curl. 



" This disease, so far as I can learn, first began to be alarming to 

 the growers of the potato, about thirty-five or forty years ago. Since 

 that time, it has continued to engage the attention of many eminent 

 agriculturists and gardeners " — Thomas Dickson, 6th March, 1810, 

 in Mem. Caled. Horf. Soc. i (1814). 



1 W. A. Orton in U.S. Dept. Agric Bur. PL Itid. Bull., No. 64 (1914). 



2 H. W. Wollenweber in PhytojKithology, v. 3, No. 1 (1913). 

 =» Elizabeth Dale in Ann. Myc. x, No. 5 (1912), p. 471. 



* Sibyl Longman in Jour. Linn. Soc. Bot., xxxix (1909). 



5 G. H. Pethybridge and E. H. Bowers in Econ. Proc. Roy. Dub. Soc, i, Pt. 14 (1908). 



