322 Plums and Plum Culture 



tissue, does not all die when winter comes; but a part 

 of it may retain its viability and go on growing the 

 following spring. These facts indicate clearly enough 

 the course of treatment which must be followed. 



The first and best remedy is the pruning knife. 

 This should be applied to every branch which shows 

 a knot, and the application should be made at the first 

 moment when the knot is discovered. Moreover, the 

 knot ought to be discovered before November. That 

 is, the plum grower should keep careful watch of his 

 orchard throughout the summer and should cut out 

 every knot as soon as it appears. In well-tended or- 

 chards this labor never becomes burdensome. It is 

 good practice in cutting out knots to cut some distance 

 below the knots, say two to six inches, depending on 

 the size of the branch, its situation on the trunk, the 

 virulence of the attack, etc. When knots are cut out 

 they should be promptly burned. 



Large knots which sometimes appear on the 

 trunks of trees or on the main branches, are more dif- 

 ficult of treatment. Sometimes it is feasible to cut 

 them out with a sharp knife, after which the wound 

 is first seared by an application of pure kerosene and 

 afterward protected by a coating of grafting wax. In 

 case the removal of the knot is impracticable, it should 

 be heavily painted with pure kerosene. This treatment 

 may be best given during the growing season. If fol- 

 lowed by spraying as directed below, this treatment 

 will sometimes suffice to save trees after the appear- 

 ance of the largest knots. Spraying, properly con- 

 ducted, is an important preventive measure; and is 

 probably worth more in the long run than the knife 

 treatment. 



It will be remembered that there are two crops of 

 spores to be guarded against. The winter spores are 

 usually clinging to the bark in the spring, awaiting the 



