198 



Bulletin 236, 



Several things were ac- 

 triecl, but the one 



6. Treatment that Promises Best Results 



Although the work of the past season has been devoted largely to a 

 study of the various manifestations of the disease, its cause and distribu- 

 tion, still some attention has been given to the means of combating it. 

 Through the kindness of several men, in different parts of the State, I 

 have had the opportunity of carrying on some experiments along this line 

 on their trees. Prevention rather than cure is one of the axioms of 

 plant pathology. In most cases the curing of a diseased plant is impossi- 

 ble, or its value does not warrant the effort required to save it. However, 



in the case of trees just com- 

 ing into bearing it seems that, 

 if possible, some means of 

 saving them should be worked 

 out. 



cordingly 



that so far gives most promise 

 of definite results is to cut out 

 the cankers (Fig. 76). With 

 a sharp knife remove all the 

 diseased tissue (Fig. 79), 

 swab out the wound with a 

 weak solution of corrosive 

 sublimate (one tablet to one 

 pint of water), or with a three 

 per cent solution of copper 

 sulfate ( I ounce to i quart of 

 water), and when dry, paint 

 over thoroughly with some 

 heavy lead paint. This should 

 be done early in the season, as 

 soon as the cankers are dis- 

 c<^vcred, for two reasons: ist, 

 the spreading of the canker 

 and its consequent damage to 

 the tree is checked ; 2d, the wound is thus given a long period in which 

 to heal. The painting should be repeated again toward the close of the 

 season and again the next year, or until the wound has completely healed. 

 This prevents a second infection or the entrance of rot fungi. A twice- 

 monthly inspection of every tree shoulcl be made and all cankers carefully 

 cut out and treated as soon as they aj^pear. Cankered trees so treated 

 early in the spring of 1905 have formed good calluses and are fast heal- 

 ing the wounds (Figs. 80 and 81). 



Fig. 73. — Recently blif^hted shoot on 

 Greening apple tree ivith well 

 active canker about its base. 



limb of 

 marked 



