11 



process releases the pressure of the bark so that the sap can flow more 

 freel3^ The bark binding- is supposed to result from the wood and 

 inner bark growing more rapidly than the tough outer bark, the strain 

 finally' becoming so great that the bark bursts and even breaks away 

 from the wood. To all of the above views there are vital objections. 

 The supposition that bark binding- interferes with the sap flow and thus 

 causes leaf curl may be dismissed as absurd, for it is impossible for the 

 bark to exert pressure enough to prevent the upward movement of 

 water in the sapwood. It is also a fact that the bursting does not take 

 place when the wood growth is greatest and the stretching of the bark 

 most intense. On the contrary, it takes place, if at all, near the close 

 of the winter season, when there is absolutely no growth. 



That the bursting could be caused b}^ low temperature alone seems 

 out of the question, as in the coast region the winter temperature is 

 so high that skating is a rare sport, and only twice in twenty years 

 has the thermometer registered zero. In the inland areas much lower 

 temperatures occur, but bark bursting is there unknown. 



With our present knowledge of the trouble no adequate explanation 

 can be given. It has been suggested that root pressure mav have 

 something to do with the phenomenon. The conditions in winter in 

 the coast region are frequently such that the roots may be active in 

 the relatively warm soil long before any leaves have developed in the 

 branches. This would result in a considerable sap pressure within 

 the tree, but it seems hardly probable that it could be great enough 

 to burst the bark, even in case of a sudden drop in the temperature. 

 Whatever the cause, the best remedy is to bind the bark at once, 

 using a liberal supply of grafting wax of some sort to keep out fungus 

 spores. The binding should be done with strips of cloth or burlap, 

 which should be tightly drawn. If this is done promptly the wound 

 will heal over nicely. 



Slitting the bark is of doubtful value. However, it can do little 

 harm, even if it does no good. 



CONDITIONS AFFECTING ORCHARDS IN THE INLAND VALLEYS. 



The Cascade Mountains separate two regions widely different in soil 

 and climate. On the one side these have fostered the development of 

 great forests; on the other almost antithetical conditions have resulted 

 in the plains and hills being practically treeless. While the coast region 

 has an abundant rainfall and no great extremes in temperature, the 

 inland region, in many parts at least, has an msuflScient rainfall and 

 the extremes of heat and cold are more marked. 



In the fruit-growing districts of the inland region there are well- 

 marked differences between the valleys, where for the most part irri- 

 gation is practiced, and the uplands, where rainfall must be depended on. 



