74 MANUAL OF TREE DISEASES 



This may seem peculiar, since there is an over-abmidance of 

 water in the soil, but it is explained by the fact that the trans- 

 porting of the water to the trunk is dependent on the healthy 

 condition of the roots and when these are injured, the power 

 to absorb water is diminished accordingly. Therefore, al- 

 though there is plenty of water in the soil, it cannot be supplied 

 to the leaves. 



The remedy for such conditions of abnormal water supply 

 may be undertaken after the symptoms are noted, if the re- 

 covery of the tree seems possible. When heavy sod, tight 

 paving or compact soil is the cause of too Uttle of the normal 

 rainfall reaching the roots, artificial means must be used for 

 watering. The best method is to keep the sod broken up, but 

 when this is not desirable, upright sections of tile may be 

 placed at intervals flush with the sod and the necessary water 

 furnished by running water into these from a hose. It should 

 be remembered that the feeding rootlets are under the edges 

 of the branches and not up close to the trunk of the tree. 

 The tile should, therefore, be placed at intervals in a circle 

 imder the tips of the branches. A certain amoimt of artificial 

 fertilizing may also be accomplished through the tiles. When 

 the soil contains too much water, the ordinary methods of 

 drainage should be employed. 



Reference 



Graves, A. H. Root rot of coniferous seedlings. Phytopathology 6 : 

 213-217, figs. 1-2. 1915. 



Fkeezing-to-Death 

 Caused by low temperatures 



Many kinds of trees are more or less injiu-ed by the freezing 

 of the roots. White pine, maple, elm and ash are particularly 

 susceptible. 



