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tissues are too weak to stop the advance of the pathogen once it 

 is well established in the plant. 



How Can Perennial Peach Cankers be Controlled? 



There is no single, effective and easy control measure for 

 this disease. One must keep in mind, however, that it is mostly 

 trees of low vigor that become infected, that the pathogen can 

 spread to trees only when it is present nearby, and that it can 

 attack trees either by penetrating through unhealed wounds or by 

 first growing on dead twigs, buds, etc. A control program depends 

 largely on doing well the many things required to keep the trees 

 in good vigor, to eliminate nearby sources of the pathogen, to 

 prevent unnecessary wounding of peach trees and aid rapid healing 

 of unavoidable wounds, and to minimize killing of bark, twigs and 

 buds by low winter temperatures. Certain fungicides have been 

 proven helpful but will not, alone, control the disease. 



The following practices followed over a period of years help 

 reduce the spread and prevent development of perennial peach can- 

 kers . 



Trees should be fertilized adequately and pruned properly to 

 insure vigorous growth. Excessive or late season application of 

 nitrogen ferilizer, which prevents normal maturing of peach trees 

 and increases their susceptibility to early winter injury, should 

 be avoided. Pruning should be done late in the spring after growth 

 starts, and even after bloom, at which time pruning wounds heal 

 quickly and are less frequently infected with canker fungi. Prun- 

 ing cuts should be made close to the branch, since stubs seldom 

 heal properly and provide ideal sites for canker infections which 

 spread to the larger branches. All dead wood and twigs, killed 

 by any cause, should be cut and, along with the prunings, should 

 be removed from the orchard and burned as soon as possible. Branches 

 with cankers should be removed whenever possible. However, if the 

 cankers are on large scaffold limbs or tree trunks, the infected 

 area should be first cut and scraped, then the cleaned-out wound 

 should be disinfected with 1 part mercuric chloride in 500 parts 

 of water, and, finally, the disinfected wound should be covered 

 with a water-asphalt-emulsion wound dressing. Hopelessly cankered 

 trees should be removed and burned. 



*Trade name 



