50 THE CANADIAN HORTICULTURIST. 



" Should it be made compulsory by law to destroy the black-knot 

 on Plum trees ?" 



Vice-President Eoy, Owen Sound, read the following paper on the 

 subject : 



This scourge of the plum tree is found in nearly all parts of 

 Ontario, and is so common and destructive that in some districts one 

 seldom sees a plum tree free from knot; and although a great deal has 

 been written in agricultural and horticultural papers, and warnings 

 given by vigilant members of both societies about the injury done to 

 the fruit crop, and the sure death of the tree if not thoroughly cut off 

 and burned, still the warning seems to be. of little avail. The disease 

 is spreading very fast, and unless some remedy, either Legislative or- 

 otherwise, is found to stop its further progress, the plum crop will 

 dwindle down to very small dimensions. When it gets into a plum 

 orchard it attacks all varieties, but most frequently upon trees standing 

 in wet dark rich soil. If the trees are planted in a dry soil they have 

 a better chance to escape the disease. 



Much has been said and written about the origin of black knot.. 

 The insect theory has long been abandoned, and nearly all intelligent 

 fruit growers now accept the knot as a vegetable excrescence of fungous 

 origin. Scientific research by entomologists and botanists has given 

 us the cause, nature, and means of propagation of the black knot ; it 

 is for us to profit by their instructions, and endeavor by every means^ 

 in our power to put down and destroy this pest. 



It spreads with great rapidity. I lately saw a blue plum tree 

 affected with black knot, and large numbers of suckers growing up all 

 around it, nearly every one of them from a foot high was affected with 

 knot, evidently showing how contagious and hereditary it is ; hence 

 the necessity of strong measures being taken to keep it down; what 

 these measures should be is for you to say. From my own observation 

 and experience, I have not much faith in moral suasion in this matter. 

 If you think.the evil can be eradicated by act of parliament, and proper 

 machinery put in motion to compel every one to keep their trees free 

 of this ugly and injurious excrescence, it will be a benefit to the 

 community, and put our people largely in possession of a most delicious 

 and nourishing fruit, with millions of bushels surplus for export, w^hich 

 will be real wealth to the country. 



There is a Bill now before the Ontario Legislature, in charge of the 



