101 



curved sides, the long diameter extending lengthwise of the 

 limb or trunk. A wound shaped in this manner will heal 

 much more readily and completely than one with rounded or 

 square ends or one extending crosswise of the limb or trunk. 



After the cutting-out process is completed, the surface of 

 the exposed wood should be disinfected with a 1-1,000 solu- 

 tion of corrosive sublimate, and as soon as this dries a coat of 

 good lead paint should be applied, using great care to cover 

 every bit of the surface. Painting over should be repeated 

 every year until the wound is entirely healed. Coal tar and 

 asphaltum are often used for coating wounds. The former 

 is apt to cause injury, and the latter is difficult to prepare. 

 Paint, if of good quality and applied each year, has been 

 found as satisfactory as any substance used. Tools used in 

 cutting out cankers should be wiped frequently with a cloth 

 or sponge wet in the disirifecting solution in order to avoid 

 carrying infection from one cut to another. It is also im- 

 portant that the operator wear rubber boots or overshoes, as 

 any wounds made in the bark are easily infected by canker 

 parasites. 



In cleaning up an orchard infected with cankers, one must 

 use judgment as to what limbs to remove and what cankers 

 to treat by cutting out. It is sometimes better to sacrifice 

 a large bearing limb if the canker has so far advanced as to 

 weaken or nearly girdle it. But where cankers on such limbs 

 are small enough to respond to treatment, the limbs should 

 be retained. 



Burning of diseased twigs, branches and bark, removed in 

 the cleaning up of an orchard, is an important part of the 

 operation, as these remain a serious source of further infection 

 if left lying about. 



Spraying probably is only indirectly beneficial in the control 

 of cankers. Keeping fruit-rots and leaf-spots in check by this 

 means undoubtedly reduces the amount of canker infection. 

 On the other hand, by keeping an orchard clear of cankers, 

 the amount of fruit-rots and leaf-spots caused by the same 

 fungi may be greatly reduced, for the cankers are constant 

 sources of infection. 



