22 



BULLETIN 317, U. S. DEPARTMENT OF AGRICULTURE. 



the stump was found to vary so little that the stump measurements 

 were adopted to show the falling off in growth for the last 10 years. 

 A study of all the cross sections of tree No. 27 showed a normal 

 growth. It also possesses a crown of larger dimensions. The two 

 trees stood within 100 feet of each other. Selecting from Table II 

 that which is of greatest moment, trees Nos. 43 and 9 may be com- 

 pared as shown in Table III. 



Table III. — Condition of larches Nos. 43 and 9, selected from Tabic II for 



comparison. 



Item of comparison. 



Tree No. 43. 



Tree No. 9. 



Age years 



Breast-nigh diameter inches 



Infection -. . 



Average width of sapwood inches 



Average number of rings in sapwood 



Width of present zone of suppression {rings 33 



Height feet 



Merchantable length do.. 



Full volume, board measure do.. 



Growth for last 10 years inches 



Relation to neighboring trees 



6 



XXX 



1.12 



23 



0.4 



30 



65 



20 



20 



0.10 



Dominant. 







1.35 



27 









 72 

 32 

 83 



1 

 Intermediate. 



Tree No. 43, as shown by the data in Table II, had burls on its 

 trunk and at the bases of branches (columns 3 and 15). A trunk 

 burl occupied 100 per cent of its total circumference (column 20) 

 and only 10 per cent of it was living (column 23). The tree had six 

 branch brooms (column 6), with an average weight of 4.5 pounds 

 (column 11), and normal branches of 3 pounds average weight 

 (column 10). 



In this manner tree No. 5 may be compared with tree No. 44; No. 

 10 with No. 11 ; No. 3 with No. 39 ; No. 5 with No. 25 ; No. 33 with 

 No. 35 ; No. 2 with No. 12; No. 30 with No. 3T; No. 33 with Nos. 35, 

 29, or 36 ; No. 18 with No. 34, etc. 



EFFECT OF MISTLETOE BURLS ON THE MERCHANTABILITY OF 



LARCH TREES. 



The effect of the formation of burls on the trunk and at the bases of 

 branches, aside from injuring the tree from a physiological stand- 

 point by cutting off the transporting tissues, introduces a cull factor 

 of no mean proportion in the present timber capital. In bucking the 

 tree it is possible in most cases to saw out the burls when they are far 

 enough apart not to interfere seriously with the merchantable log 

 length. In badly infected specimens the trunk and branch burls 

 (figs. 5, 8, 9, and 10) are frequently so close together and so evenly 

 distributed along the trunk that little merchantable material can be 

 obtained. Sometimes these burls take up the entire merchantable 



