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heart rot. This holds true for practically every kind of tree. 

 This fact alone would condemn the practice of topping. Besides 

 topped trees, 19% of the untopped trees were rotten from 

 wounds and bad pruning. This means, then, that 38% of the 

 city's most numerous trees have been ruined by neglect and 

 maltreatment. No diseases were apparent in sufficient abun- 

 dance to endanger the life of the trees and only 1.6% were dead. 

 As the summer was very hot, many of the soft maples had tip 

 burned, especially on boulevards where they were subjected to 

 intense heat from the pavement. 



Elms 



The survey was deemed necessary from the continued and 

 extensive death of elms. For the past five years, elms, both 

 American and Slippery, had been dying in great numbers. For 

 the past three years the rainfall had been low in midsummer and 

 drouth had been long, so that the water table had been greatly 

 reduced. This lack of water has been attributed by many as the 

 cause of the death of the elms, but it was found that in addition 

 several diseases were killing the trees. 



In Danville three diseases were most apparent and of them, 

 one was most injurious. Nearly 3,000 elms were examined and 

 of these 63% were healthy, 26% were sick, and 11% were dead. 

 Elms constituted 15% of the trees and more than 1,000 were 

 sick or dead. The one fungus causing most of this destruction 

 seemed to be Xylaria, sl root disease. The other two diseases, 

 Coniothyrium and Vermicidaria, limb diseases, were killing 

 fewer trees. 



The apparent methods of attack for these diseases will be 

 given. Xylaria attacks first the young rootlets of the elm and 

 in the early stages the tree shows a slight thinning of the leaves. 

 Only after examining hundreds of elms does this early con- 

 dition become apparent and then all that can be said is that 

 the tree does not look quite right. The growth in the twigs will 

 be noted shorter for that year. Then as the disease works back 

 along the root it is killing, the tree shows this condition in two 

 ways: Either there is a general, very apparent thinning of the 

 leaves and the growth is short, or small limbs and individual 

 leaves throughout the tree will turn bright yellow and fall. 

 From then on, in the third or fourth year, the progress of the dis- 



