WEYMOUTH PINE 413 



Average returns from pure crops in high forest should be, 

 per acre : 



Thinnings , . . 1350 cub. ft. to 2 in. q. g. 

 Final yield (at 80 years) . 4270 6 

 Total production . . 6300 2 



Average annual increment, 79 cub. ft. to 2 in. q. g. 



Equivalent net rental l for land only \ at 3% = 43. id. 



(from date of planting) J at 4% = minus is. $d. 



Of Fungi. Many of those attacking Scots Pine also 

 attack the Weymouth Pine. 



Agaricus melleus and Trametes radiciperda very 

 frequently cause much damage. 



Peridermium strobi, sometimes called P. ribicolum, is the 

 Weymouth Pine Bark Blister. It often does enormous 

 damage to young crops. It is characterised by pinky red, 

 bladder-like vesicles, which appear on the stems. 



Other fungi attacking the Weymouth Pine are : 

 Hysterium pinastri, Botrytis cinerea, Caeoma pinitor- 

 quum, Trametes pini, and Peridermium pini acicola. 



Of Insects. Most of those attacking Scots Pine will also, 

 occasionally, attack Weymouth Pine ; though, generally 

 speaking, the tree is not nearly so subject to insect attacks as 

 the Scots Pine. 



Pissodes notatus is, however, fairly common in Scotland. 



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

 the crop. 



