9 



quantity there, and these form an excellent medium in which the spore can 

 lodge and develop. Avoid injuries to the bark, such as " whiffletreeitis." 

 Keep the tree in condition to withstand winter injury. A thrifty tree is 

 in better condition to withstand attack and to renew any injured parts. 



It would be advisable to gather the fallen fruit, especially in an orchard 

 where the disease has been serious. This might form a medium for reinfec- 

 tion not only for this disease, but for others such as apple-scab. Hogs are 

 satisfactory in the orchard for this purpose if ringed to prevent them from 

 doing damage to the trees. 



TREATMENT OF CANKER. 



In addition to the above methods of control and spraying, it is a good 

 plan to watch the trees closely, and where any cankers are found developing 

 to open them with a knife. Cut open the canker, not necessarily into healthy 

 wood, but enough to allow the air to gain entrance and dry out the spot. 

 Leave this open for a day or so, and then disinfect the wound with corrosive 

 sublimate. 1 to 1,000 (one of the cheapest and best disinfectants to use for 

 tree injuries), or Bordeaux mixture (4-4-40). Paint over the wound with 

 oil and lead, with some colouring material if desired (use no turpentine with 

 paint). 



SPRAYING. 



Spraying to control the disease, when applied thoroughly at the right 

 time with the correct sprays, has given satisfactory results, and has led 

 us to believe that infection can be prevented by this method. 



Knowing the habits of the pest as outlined above, the fruit-grower is in 

 a position to appreciate the necessity of carrying on his spraying in an 

 intelligent manner. The " roots " of the disease being situated under the 

 outer covering of bark, it stands to reason that it would be impossible to 

 destroy them without using a spray so strong that it would do serious damage 

 to the tree. It is similar to the case of apple-crab (Venturia inequali*), where 

 if you coat the scab with Bordeaux mixture or similar fungicide it will 

 continue growth. It is impossible to check the disease with our ordinary 

 sprays after it has started growth, and the control by means of spraying 

 lies in a method of prevention. The spores are easily killed by a fungicide 

 such as Bordeaux mixture or lime-sulphur, and prevention lies in spraying 

 to kill the spores before they have germinated and gained an enti'ance into 

 the host. These spores are microscopically small, so the reader can under- 

 stand the necessity of thorough work in order to obtain satisfactory results. 



TIME OF APPLICATION. 



Where winter varieties of apples are grown it is impossible to use the 

 ordinary sprays until the fruit is picked, and this is generally too late to 

 obtain the best results. This is not important in the Upper Country, but 

 it is in the Coast districts, where the disease does so much damage. Winter 

 varieties of apples in the Coast districts are not to be recommended on this 

 account. Spraying to control must be done early in the fall, about the time 

 the fall rains begin. The leaves will likely be on the tree at that time, so, 

 besides the control of black-spot canker, the spray will be beneficial in the 

 control of other pests on the tree. Besides this spraying, the writer is of 

 the opinion that another spraying should be applied immediately after the 

 leaves fall, in order to insure thorough work, and to take the place of some 



