FRUIT TREES AND THEIR ENEMIES 171 



of farm stock, or damage to trunk or branch in 

 stormy weather. 



The remedies for canker are few and but 

 little understood, which may also be said of 

 the causes which bring about a diseased condi- 

 tion of the trees. Badly affected orchard trees 

 should be uprooted and burnt, while, in less 

 virulent cases, carefully cutting away and 

 destroying the diseased portions and painting 

 the wounds with tar is to be recommended. 

 Preventive measures are best, and consist in 

 spraying the trees with copper sulphate im- 

 mediately after the fall of the leaf. Sulphide 

 of potassium, in the proportion of 10 oz. to 

 35 gallons of water, has had good effect when 

 applied to slightly affected trees in some of the 

 Kentish orchards. 



Apple and pear scab (Fusic/adium dendriticum 

 and F. pyrinum) cause considerable anxiety to 

 the cultivator of hardy fruit. These are fungi 

 which cause both leaves and fruit to become 

 mottled with dark patches. When attacked, 

 the fruit development is arrested, and in the 

 case of the pear cracking is the usual ac- 

 companiment of this fungoid disease. Certain 



