248 GARDEN FOES. 



It produces a mass of orange-coloured si)orcs on the 

 foliage. 



Kemedies. — There is very little to be said in the way of 

 treatment save that of cutting and burning all affected 

 plants. 



The Black Spot (Actinonema rossc, Fr.).— The Black 

 Spot is a very widespread and conspicuous disease of the 

 rose, first described in 1826, now known in many coun- 

 tries and often much dreaded. The foliage when attacked 

 soon develops the characteristic black spots, and the leaves 

 becoming elsewhere pale shortly fall to the ground. As 

 a result rose houses badly infested with the black spot 

 show but few leaves and fewer blooms. Once trees are 

 badly attacked there is no remedy except to remove and 

 burn the infected leaves. 



Remedies. — As a preventive, spray periodically in spring 

 and sunnuer with a solution of sulphide of potassium; 

 also in winter with the Cupram Formula (No. 25). If 

 many leaves have fallen from the plants they should be 

 gathered up and burned. As with many other diseases, 

 some varieties are more liable to the black spot than 

 others. When possible — that is, when all other things 

 remain the same — it is. of course, wise to grow those 

 least susceptible to the disease. 



