372 THE MONTHLY BULLETIN. 



ence therefore of fungi on the dead parts of a tree does not necessarily 

 show that they were the cause of the death, though they may have been. 

 Recognizing this relation or fight between the tree and certain fungi, 

 the fruit grower naturally takes the side of the tree against the fungi and 

 employs specialists with their microscopes and culture dishes, etc., to tell 

 him, if possible, what each kind is doing, how best the tree may be 

 assisted in its fight, and when and where to strike the fungus as it threat- 

 ens the tree. 



Preventive Measures. 



Some of the different means of prevention of fungus attack that may 

 be used under varying conditions are : 



1. Surrounding the tree with the most favorable conditions for vigor- 

 ous growth and resistance ; or, 



2. Planting only those varieties or strains known to be resistant to 

 attack ; or, 



3. Keeping the trees away from sources of infection; or, 



4. Where these measures fail or are impracticable, covering its parts 

 with a fungicide or its cuts or wounds with a suitable substance to keep 

 the fungi out. 



In the short time allowed for this paper only a few cases will be taken 

 up, all of which come under the last two means of prevention, e. g., that 

 of keeping the plant away from sources of infection, and protecting it 

 with surface applications of sprays or other substances. 



Protecting Wounds and Cut Surfaces. 



The protection of wounds or cut surfaces in fruit trees is of great 

 importance. It is a common thing in some orchards to see projecting 

 stubs more or less prominent left where limbs or branches of considerable 

 size have been cut off. In many cases these stubs have died back and are 

 seen to be rotting inward toward the heart wood. Whether toadstool or 

 other fungous growths are visible or not, the rotting and decay is almost 

 sure to be due to them. These fungi are usually only wood destroying 

 forms and could easily have been prevented from entering. In cutting 

 off limbs, it is of importance that they be cut flush with the remaining 

 limbs and cut smooth. It is better to leave no projection at all, even 

 though this requires a cut two or three times as large. The cut surface, 

 if protected by suitable covering to keep out fungi, will heal over rap- 

 idly and leave a smooth surface. Butchering and hacking trees in the 

 manner sometimes seen, is just an invitation to the weakest parasite to do 

 its best in injuring the tree. In a small degree, at least, cutting off a 

 hardened branch is like cutting off a finger. If a cut finger is allowed to 

 be dirty and not disinfected, blood poisoning and pus formation will or 

 will not set in, depending on the presence or absence of injurious bac- 

 tei'ia, and in the same way slow rotting and decay will follow a cut or 

 injury to a tree depending on whether injurious fungi or bacteria are 

 present. If the wound is covered with a substance that is waterproof 

 and at the same time a disinfectant, chance of decay is prevented. A 

 covering for cuts and wounds that has been found most useful for this 



