462 



BOAED OF AGRICULTURE. [Pub. Doc. 



and the other two seasons their foliage had been eaten badly 

 by the tent caterpillar and canker worm. Had these trees 

 been sprayed each season, and their fruit thinned when too 

 heavily set, no doubt they Avould have made some annual 

 growth, especially if they had been kept in a good state 

 of fertility. 



Some of the causes which delay the healing of wounds 

 are illustrated by the accompanying figures. 



Fig. 18 shows a large wound, 12 by 18 inches, at the base 

 of an apple tree probably eighty years old. This wound 

 was made in November, 1895, and up to July, 1902, it had 

 not healed at all. The age of the tree, the size of the wound. 



WU.} 



Fig. 18. — Wound at base of old 

 apjjle tree. This wound failed to 

 heal at all in six years. 



-■■4' 





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-i. «~^.— V 



Fig. 19. —This large wound ou trunk 

 of apple tree has healed little in six 

 years. 



and its situation near the l)ase of the tree, are all strong 

 influences to prevent healing. But the tree is still growing, 

 and, were it not that it still bears fruit in some seasons and 

 is stripped by insects in others, we might expect some 

 healing. 



Fig. 19 shows a wound on an apple tree, only about fifty 

 years old. As the wound is smaller than the other, being 

 only 8 by 10 inches, and 4 feet from the ground, it has 

 begun to hoal, but in six years has healed only a little at 

 each side, and none at top or bottom. The conditions as 

 regards insects and fruit bearing are about the same as with 

 Fiff. 18. 



