454 



New Phoma Disease of the Swede. 



is perhaps one of the best known species. Frank has given* 

 a full account of its attack upon the leaves and root of the- 

 sugar beet, but he only cites it as occurring in France and 

 Germany. McWeeney* has since noted the appearance of 

 the disease in Ireland ; and its distribution is extended to the 

 north of England by my discovery of its presence on a farm 

 at Riding* Mill, near Newcastle, in 1896, where many of the 

 mangel roots were found strongly attacked by Phoma Beta: 

 when the pits were opened in the spring. Rostrupf has also- 

 described a Phoma attack on the carrot under the name 

 P. sanguinolenta. 



The only reference to any similar attack of the swede- 

 which I have been able to find is a short note by Rostrup of 

 a Phoma attack in Denmark. He describes it under the 

 name P. nafiobrasstcce, and states that "The disease at pre- 

 sent has only been observed appearing to any great extent 

 on a large farm at Falster, and is not known in foreign 

 countries/' It is possible that the attacks occurring in. 

 England and Denmark may be due to the same species, but 

 Rostrup gives no figures or measurements of the spores and 

 mentions no cultures, and his description is too meagre for 

 any certain determination. Prillieux' description of Phoma 

 Brassiere (Thiimj, which attacks the stalks of cabbages and 

 has been especially destructive in the west of France, agrees- 

 very closely with the form I am now describing on the 

 swede. The shape and measurement of the spores are the 

 same, but Prillieux does not mention the colour of the 

 emergent spore-mass. The characters given of P. sangumo- 

 lenta are also very similar, notably that of the colour of the 

 spore-mass. These may eventually prove to be forms of the 

 same species. 



With reference to methods of checking the disease, it is at 

 present only possible to suggest general principles of reme- 

 dial treatment, which, from researches into the nature and 

 growth of fungoid diseases, we know to be essential. Having 



McWeeney, ( Observations on Phoma Beta (Frank), a Fungus that injures Mangel.. 

 Journal Roy. Agric. See. Eng., Series III., Vol. VI., 1895. 

 ! Rostrup, Sygdornme hos Landbrugsplantner, 1893. 



