CHAPTER VIII. 



INJUKIES TO TREES. 



The causes of injury to tree growth are many and various; 

 some affecting- principally the cultivated trees in windbreaks 

 and shelter belts, and others affecting the forest plantations 

 and large areas of timber; some injure or destroy the trees or 

 tree seeds and others do damage to the land on which they 

 grow. 



Saw-Flies and Tent-Caterpillars. At present perhaps the most 

 serious injuries to cultivated trees in this section* result from 

 the neglect to take precautions against leaf-eating insects, 

 such as saw-flies and tent-caterpillars. These injuries may 



be largely prevented by 

 the use of Paris Green 

 in a liquid form, ap- 

 plied by means of a 

 force pump, using the 

 solutions from a barrel 

 carried in a wagon or 

 on a stone boat. An or- 

 dinary spraying nozzle 

 should be used with a 

 sufficient length of hose 

 to reach up into the 

 tree. In order to reach 

 the tops of the trees it 

 may be necessary to 

 have a raised platform 

 on the wagon and to 

 attach the nozzle to the 

 end of a long bamboo 



nolp Tn mrxst nrair-i^ 

 P 16 - 



groves this is practica- 



Figure 25. Elm tree that has been 

 planted five years and was pruned to a 



bare pole when set out. 



