CONCERNING THE DURABILITY OF THE WOOD OF THE 

 MAIDENHAIR TREE, GINKGO BILOBA 



By Henry Schmitz, 

 School of forestry, University of Idaho 



It is 'a matter of common observation among horticulturists and 

 gardeners that the maidenhair tree is unusually free from heartwood 

 decay. 



Although being an oriental species, Ginkgo biloba is now extensively 

 planted throughout the warmer regions of the middle west and east as 

 an ornamental tree. In these regions, the tree makes very good growth, 

 often increasing in diameter at the rate of one-ihalf inch per year. In 

 the Northwest r.nd Pacific Northwest, the tree makes practically no 

 growth. This n.ay be due to the absence of warm nights during the 

 growing season. 



The fact that the tree makes very good growth in certain sections of 

 this country and its desirable form for the production of fence posts 

 together with the probable durability of the wood suggested to the 

 writer that the maidenhair tree might be suitable for planting in farm 

 woodlots provided that the wood is as durable as generally thought. 



In order to test the durability of this wood, it was subjected to the 

 action of six common wood-destroying fungi. The method used was 

 briefly as follows : Small blocks, approximately 1 by 1 by 2 inches 

 were sawed from a piece of sound heartwood. These blocks were 

 dried to constant weight in an oven at 100 degrees C. and carefully 

 weighed. Six blocks were then placed in each of seven 1-quart Mason 

 jars having a layer of absorbent cotton on the bottom. The cotton and 

 blocks were moistened with distilled water, the jars plugged, and ster- 

 ilized at 15 pounds pressure for 20 minutes. After sterilization, one 

 flask was inoculated with each of the following fungi : Lenaites saepi- 

 aria Fr., Polystictus versicolor (L.) Fr., Fomes pinicola Fr., Trametes 

 pini Fr., Fomes roseiis Fr., and Poly poms lucid us (Lys.) Fr. 



After four months' incubation at room temperature, the blocks were 

 removed from the flasks, the fungous mats carefully removed from the 

 blocks, the blocks again dried to constant weight at 100 degrees C. and 



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