THE HEVEA RUBBER TREE IN THE AMAZON VALLEY 3 
At this time a combination of circumstances occurred which gave 
a great stimulus to rubber planting in the Orient. A deadly rust 
disease of coifee (Hemileia vastatrix Berk, and Br.) completely 
ruined the coffee plantations of that part of the world, and the planters 
in desperation were seeking a substitute crop. Rubber, as one of the 
most promising crops, engaged their attention, and soon large acreages 
were planted with Hevea brasiliensis. 
In a few years considerable plantation rubber appeared on the 
market and, in spite of the early skepticism of the manufacturers, 
continued to be produced in larger and larger quantities. Im- 
proved methods of preparation gradually removed most of the ob- 
jections to its use, until now it is considered the equal of fine hard 
Para, long the highest quality of rubber known. 
With the passage of years many types of rubber disappeared 
completely, either because of the exhaustion of their sources or the 
decline in price which made their production unprofitable. Planta- 
tion rubber has constantly assumed larger proportions in the world's 
markets, while wild rubber has steadily become of less importance, 
until plantation rubber has come to control the situation completely. 
Wild rubber is now obtained from relatively few plants, and unless 
certain special uses demand certain types the exploitation of the 
wild product must soon cease altogether. 
The United States is now the largest consumer of rubber, while 
the plantation-rubber industry is centered in the Orient, in India, 
Ceylon, Burma, the Federated Malay States, the Straits Settle- 
ments, Sumatra, Java, and Borneo. This wide separation of con- 
sumer from source of supply has given concern to many, who have 
pointed out the need of sources of supply nearer home which could 
be drawn upon in case the more distant sources were cut off by war. 
In addition to this, the control of this raw product, so vastly im- 
portant in our transportation system, by foreign powers was empha- 
sized by a recent restriction act which aims at the control of the 
price of rubber. These and other considerations led to the initiation 
in 1923 of a series of investigations of the sources of crude-rubber 
supply undertaken by the United States Department of Agriculture 
and the United States Department of Commerce. This report 
embodies the results of one of the investigations conducted by the 
United States Department of Agriculture. 
PURPOSE OF THE EXPEDITION 
An expedition was sent to Para, Brazil, in July, 1923, to make a 
study of the botanical phases of the rubber industry on the banks of 
the Amazon and its tributaries. The problems to be investigated 
may be stated as follows: 
(1) The general status of the rubber industry in the Amazon region at the 
present time, including a study of present methods of production and the possi- 
bility of improving them. 
(2) The rubber resources of the region available in case of a crisis and the means 
of making such resources available. 
(3) The suitability of the region for the cultivation of rubber, especially as 
determined by the growth and development of the trees. 
(4) The types of Hevea and the possibility of securing more desirable strains 
for plantation use in the Amazon Valley or elsewhere. 
(5) The prevalence of diseases of Hevea and plant pathological conditions 
generally. 
