Failure to save some of the affect- 

 ed trees by pruning could be at- 

 tributed to (1) excessive infection 

 of the crown, (2) spread of infec- 

 tion into the trunk, (3) too long 

 delay in the pruning operation, or 

 (4) insufficient amount of pruning. 



It is obvious, then, that pruning 

 cannot be effective unless disease 

 symptoms are detected early, for 

 example, when foliage symptoms 

 are restricted to one major branch 

 and when no discoloration of the 



sapwood extends into the trunk. 

 An affected branch must not only 

 be removed promptly to prevent 

 spread of the contagion throughout 

 the tree but must also be removed 

 back to the trunk to insure com- 

 plete elimination of the fungus. 



Dutch elm disease is so deadly 

 that it may reasonably be assumed 

 that trees affected with the fungus 

 will decline quickly unless pruning 

 is done promptly. 



Advantases In Pruning 



1. Prompt action may save 

 irreplaceable trees. 



2. Cost of operations may be 

 substantially less than cost of 

 removing entire tree. 



3. Incentive created to watch 

 and protect special trees of com- 

 mons and parks. 



4. Threat to near-by elms les- 

 sened by reducing material suit- 

 able for breeding of elm bark 

 beetles, carriers of the disease. 



Disadvantages In Pruning 



1. Pruning cannot be delayed 

 to estabUsh certain identity of 

 disease. 



2. Disease may not be com- 

 pletely eliminated. 



3. Value of pruning may be 

 discredited because of misuse as 

 cure-all or panacea. 



4. Its probable success, extent, 

 and relative merits can be eval- 

 uated only by trained and ex- 

 perienced operators. 



5. Danger of accidents from falling parts of weakened trees 

 minimized. 



6. Inconvenience and hazards in removing trees greatly curtailed. 



7. General program for detection of disease materially aided even 

 if the restrictive pruning is not successful. 



Errata: Vol. 1, No. 1, p. 11, par. entitled "First Cutting for Silage." First 

 sentence should read: 



"Because no methods of hay storage that will eliminate or at least minimize these 

 losses (of valuable constituents, especially carotene and sugar) have as yet been de- 

 veloped on a practical scale, farmers would do well to look into the possibilities of storing 

 a maximum tonnage of their first cutting of grass as silage." 



Page 11, last line, "discarded" should read "fed out," 



15 



