VANCOUVER DOUGLAS FIR 391 



system or the group system, provided that home-grown 

 seed prove satisfactory in every respect. 



Rotation. This, in even-aged high forest, is about 55 to 

 75 years. 



Average Returns from pure crops in even-aged high 

 forest should, on Quality I. soil, amount per acre to : 



Thinnings . * . 9,620 cub. ft to 2 in. q. g. 

 Final yield (at 75 years) . 11,200 6 

 Total production . .21,190 2 



Average annual increment, 282 J cub. ft. 



Equivalent net rental 1 for land only ") at 3% = 3, 33. od. 

 (from date of planting) I at 4% = 2, is. 7d. 



Of Fungi. Many of those enumerated as attacking 

 other conifers will also attack Douglas Firs ; but up to the 

 present there is not sufficient evidence to detail any complete 

 list of fungi which can be considered very frequent in this 

 country. 



The tree is by no means free from fungous attacks, and 

 it should on that account be planted only in localities 

 suitable to its growth. 



The Honey Fungus and Trametes radiciperda ( = Fomes 

 annosus) attack it. 



Phoma pithya causes a canker on the twigs, branches, 

 and small stems. 



Botrytis cinerea ( = B. Douglasii) attacks the foliage and 

 young shoots of the current year's growth. 



Pestalozzia Hartigii causes a bark canker on the twigs 

 and stems of seedlings and young plants. 



Of Insects. Many of those attacking other conifers 

 will, in all probability, also attack the Douglas Fir. 



The Pine Weevil ( = Hylotoius abietis), and Cockchafer 

 grubs attack young plants. 



1 After deducting interest on 8, the cost of planting and establishing 

 the crop. 



