6 THE CHINESE WOOD-OIL TREE. 



the Chinese trees. This problem still remains to be determined, but 

 will doubtless be settled in the course of a few months. There seems 

 to be no basis for the theory, however, that the oil produced here 

 by the same species of tree will be materially different from that 

 produced in China. Whatever differences have already been observed 

 in the small samples which have been expressed from the nuts pro- 

 duced in Florida are attributed by Dr. Rodney H. True, of the Office 

 of Drug-Plant, Poisonous-Plant, Physiological, and Fermentation 

 Investigations, to the method of extraction of the oil rather than to 

 any specific difference in its composition. 



SUMMARY. 



To sum up the whole wood-oil situation as it stands to-day in the 

 minds of investigators of the Department of Agriculture: 



An important plant industry, involving a present area of 40,000 

 acres and a possible one of several times this acreage, is here repre- 

 sented. 



Chinese wood-oil trees have grown and fruited well in South Caro- 

 lina, Florida, Alabama, Louisiana, Mississippi, Georgia, Texas, and 

 California. These trees are growing on cheap land and do not require 

 very careful attention. The tree has stood a temperature as low as 

 4° F., at Clemson College, S. C, without injury, except the loss of a 

 few of the small lateral branches, and is slow to start into growth 

 even when subjected to a temperature of 80° F. It is therefore not 

 so liable to be injured when this temperature is immediately fol- 

 lowed by a drop to 18° F. There are large regions in the South where 

 the temperature for decades at a time does not go below zero Fahren- 

 heit, and it is in these that it should be tried. Until it is known just 

 how low a temperature the wood-oil tree will stand without injury 

 it is not safe to predict the northern limit of its probable cultivation. 



The distribution of several thousand wood-oil trees through the 

 South in 1906 and 1907 has brought in a considerable amount of infor- 

 mation as to the behavior of the tree in this country. From these 

 data it appears that the tree has done best in the more moist parts 

 of the Gulf coast region, on deep loam soils which are underlain with 

 stiff clay. The sticky gumbo soils of eastern Texas seem unfavorable 

 to its growth, and it has not done well on the almost pure sand soils 

 of Florida. 



The wood-oil tree quickly recovers from frost injury, sprouting 

 up again from the stump. Being of rapid growth, it should recover 

 more quickly than an orange tree. The indications are that the 

 blooms may be occasionally caught by late frosts, as they open in 

 March in the latitude of Tallahassee, Fla., but in this respect they 

 seem to be less liable to injury than pear and peach trees. 



[Cir. 108] 



