176 AMERICAN POMOLOGY. 



the sap. In some limbs of small size, a patch of dead tis 

 sue of moderate dimensions would entirely arrest healthy 

 action early in the season, and destroy the portion of the 

 branch v beyond it ; in other branches of greater size, quite 

 a large patch of the dead bark might exist for a long time 

 without entirely surrounding them, and arresting the cir- 

 culation, which would thus be kept up until a later period, 

 when at length this occurred, the symptoms of blight 

 would appear. 



The treatment of this malady is quite unsatisfactory, 

 and gives us no clue to the cause of the trouble. Various 

 plans have been suggested, the most satisfactory is the re- 

 moval of the affected limbs not that it cures the disease, 

 but because it takes from us the sad mementos of our loss. 

 We have been advised to pare away the diseased portion 

 of old bark with a spoke-shave, or some similar instrument ; 

 but it is apprehended that few persons would ever find 

 this patch of deadlbark until they have the fatal evidence 

 of the blighted foliage, and no possible good can result 

 from its removal at that time. 



This trouble is connected, in many instances, with an ex- 

 cessively vigorous growth of shoots ; indeed, some of 

 those varieties which are most thrifty, suffer the most, 

 while those which make firm and moderately short shoots, 

 seldom blight. Hence it has been inferred by some, that 

 if we can check this excessive vigor, and. reduce the wood 

 growth to a moderate amount, not exceeding ten or 

 twelve inches, annual extension, we shall be able to pre- 

 vent the occurrence of blight. This object is easily at- 

 tained by root-pruning the trees severely in the spring of 

 the year. So far, we can only say that trees so treated, 



