SPHAERELLA 195 



in this country, and is also too well known on the continent 

 and in the United States. When the injury is severe the 

 crop of fruit is much reduced both in quantity and quality ; 

 the plants are also weakened for the following season. 



Ascigerous form. Perithecia often arranged in concentric 

 rings, globose, black, bursting through the epidermis, 90- 

 130 p diam. Asci oblong, 8-spored, 40 [i long; spores 

 hyaline, 1 -septate, slightly constricted, 15X3-4/*. 



Conidial form. Conidia bursting through the epidermis 

 in tufts on the whitish spots ; conidia narrowly elliptic-oblong, 

 continuous or 1-3-septate, variable in size, 20-50 x 2*5-4 /*, 

 hyaline. 



If spraying is commenced sufficiently early, in fact where 

 the disease has previously been present, spraying should be 

 commenced when the leaves are quite young, using potassium 

 sulphide solution an epidemic may be arrested. This 

 treatment will also arrest the possible appearance of straw- 

 berry mildew. Spraying should be continued at intervals 

 until the flowers begin to open. 



Professor Trelese, who has carefully studied the disease 

 in the United States, advises the following method for 

 eradicating the disease, a method which I have proved on 

 more than one occasion to be highly successful. ' The most 

 convenient way of effecting this is by mowing badly rusted 

 beds soon after the fruit is gathered, covering the dry tops 

 with a light coating of straw, or harrowing up the old 

 mulching, and burning them. This may seem harsh treat- 

 ment for the plants, but it has been resorted to by many 

 berry-growers for the destruction of insects with most 

 satisfactory results; and every one who has tried burning 

 over a strawberry bed has been surprised by the vigorous 

 and healthy appearance of the new foliage which soon 

 unfolds. 



Prillieux, Malad. des Plantes Agric, 2, p. 268 (1897). 



Beet and mangel rot. A disease doing much damage in 

 this country and on the continent. It is caused by 

 Sphaerella tabifica, Prill, and Del. {=Phoma betae, Frank, 

 and Phyllosticta tabifica, Prill, and Del.). About the month 

 of August the leaves droop to the ground, as is frequent 

 during hot, dry weather ; this drooping, however, is permanent, 

 and is caused by the fungus attacking the upper surface of 



