REPORT OF THE SOCIETY 45 



many insects, which, when feeding on it, become smeared on their legs and 

 mouth parts. They then visit the opening blossoms and deposit bacteria 

 which multiply in the nectaries and then pass down into the stalk of the 

 flower, and thence into the twigs, and branches. The sucking insects may 

 also introduce the bacteria into succulent parts, such as twigs and suckers. 

 This process of re-inoculation goes on through the whole season, leaving, 

 when the wood becomes dormant, many cases of "Hold Over Blight." 



Means of Control. 



The germs of the disease, as we have already said, hibernate along 

 the outer margin of the diseased tissue, between the living and dead wood. 

 They are massed at these points and await the rising of sap in the spring 

 to continue their development. It is up to us to destroy these germs before 

 the awakening of spring. Therefore, in winter, or early in spring, it is ad- 

 visable to examine the trunk and larger limbs of fruit trees to see if there 

 are any cankers which must be immediately cut out. In doing so, great care 

 should be taken to cut out not only the affected area of each canker but also 

 a portion of the surrounding healthy tissue of the bark so as to be certain 

 of destroying all bacterial germs. Then one ought to apply to the wound 

 some white lead paint, and burn all that has been cut off. 



In the early part of summer when Pear Blight is more apparent in the 

 orchard, being detected by the sticky liquid exuding from the bark, a 

 new inspection is necessary in order to destroy any affected area that has 

 been overlooked during the winter visit. 



In summer, two weeks after the blooming time, a third inspection 

 is necessary in order to cut out all flowers attacked and also to destroy any 

 affected new shoots or suckers that may appear, taking special pains to al- 

 ways cut 12 inches below the apparently affected area. 



Also, a good preventive is to take out all suckers before they have had 

 any chance of being attacked. A good way to control the dissemination 

 of the disease is to be merciless towards aphids. It is not desirable to do 

 the regular pruning while cutting out blighted wood. Germs would most 

 probably be carried to sound parts of the tree. 



It is necessary that after each cutting of any diseased portions the 

 tools used be disinfected by bichloride of mercury or corrosive sublimate, 

 1 part in 500 parts of water. The wounds must also be disinfected. 



As pear trees are favorite hosts for Fire Blight, Quebec will not have 

 to suffer so much from Pear Blight as Ontario, since we have comparatively 

 few pear trees. The apple tree is more lightly attacked. 



