212 NEBRASKA STATE HORTICULTURAL SOCIETY. 



There are three ways in which the careless pruner can 

 greatly endanger the life of the tree. First by leaving a jagged 

 or split surface. Second by letting the bark peel back from 

 the wound. Third by cutting the limbs where it is most con- 

 venient, leaving stubs of various lengths. It is not to be under- 

 stood that all such wounds lead to wound-rot diseases, but the 

 point is that they may induce them, since on every wounded 

 surface a certain amount of death and decay are inevitable. On 

 a jagged or split surface there is necessarily a large amount of 

 decay. This decaying organic matter together with the mois- 

 ture it absorbs, forms an excellent culture medium. To this 

 fertile medium bacteria and spores of the wood-rotting fungi 

 are brought by rain and wind. Under these conditions the 

 spores germinate very rapidly. The bacteria are not so much 

 to be feared as the fungi belonging to the toadstool family, as 

 the former are only prominent in the early slow process of decay. 

 The filaments of the fungi penetrate the entire trunks of large 

 trees, causing them to decay. One is everywhere familiar with 

 the fruits (sporophores) of these fungi growing upon dead logs 

 and even upon the decaying parts of living trees. The germi- 

 nations of the spores consists in sending out delicate threads 

 which gradually work their way from the wound through the 

 trunk and branches causing decay as they proceed. It often 

 happens that the conditions do not favor the formation of the 

 fruits on the surface and the cause of decay may not be evident. 



In this state there seem to be very few if any species of de- 

 ciduous trees free from the attacks of this fungi. This was 

 brought forcibly to my mind about a month ago when I saw an 

 Osage tree in its last stage of decay as the result of the work of 

 one of these fungi. There are some species which only work 

 on a certain variety of trees, while others are very general in 

 their attacks. Thus it is impossible for the pruner to exercise 

 too much care to insure the safety of the tree. 



In case it is necessary to make large wounds they should be 

 dressed. The dressing does not hasten the healing but allows 

 it to go on without interruption. Professor Bailey says: "A 

 good dressing is one which is antiseptic and durable, which af- 

 fords mechanical protection, and which does not itself injure 

 the tissues. Lead paint is perhaps the best single dressing or 

 preservative for wood wounds." 



