December 1, 1916.] 



THE INDIA RUBBER WORLD 



133 



Guayule Cultivation In the United States. 



A RUBBER PREPAREDNESS SUGGESTION. 



THERE is a real prospect that the United States may yet 

 become an important rubber producing country. The 

 humid tropical climate essential to the growth of laticifer- 

 ous rubber bearing trees is lacking, but the silver colored guayule 

 shrub (Partheiiium argentatum), a member of the aster family, 

 grows wild in many sections of the American Southwest as it 

 does over the central plateau of Mexico. What American enter- 

 prise did previous to 1910 in Mexican guayule fields is well 

 known. But the long continued series of revolutions in Mexico 

 reduced the average yearly export of 10,000 to"ns of guayule rub- 

 ber to 720 tons in 1914, 2,555 tons in 1915 and 1,408 tons during 

 the 12 months ending June, 1916. 



It is not surprising that in 1911 there were 6,000,000 acres of 

 guayule grov/ing wild in Texas alone, because these guayule 

 lands belong to the same belt of which the Chihuahuan desert is 

 a part. This great possibility remained neglected for the most 

 part as long as Mexican export continued, because of the high 

 cost of American labor, but with the supply interrupted and con- 

 ditions in our sister republic showing scant signs of early im- 

 provement, state officials and rubber men turned their attention 

 to it. Experi- 

 ments in several 

 localities i n d i - 

 cated that guay- 

 ule, in the United 

 States, as in 

 Mexico, responds 

 readily to culti- 

 vation, yielding 

 increased growth 

 and greater stor- 

 age of rubber in 

 its tissues. Not 

 only does it se- 

 crete rubber of 

 excellent quality 

 in both root and 

 stem, but its cul- 

 ture involves 

 fewer difficulties 

 than any other 

 commercially im- 

 portant rubber 

 plant, and it 

 thrives best on 

 lean soils in a 

 dry climate. 

 These facts ren- 

 der it so good an 

 investment of the 

 capital needed 

 that the first Ari- 

 zona ' plantation 

 of 9,200 acres, to 

 cultivate it on a 

 commercial scale, 

 promises to be 

 the forerunner of 

 many others soon 

 to follow. 



Here, indeed, lies an unparalleled opportunity to turn our 

 vast acreage of arid waste lands to profitable use. What this 

 means to the nation is not difficult to compute. The western 

 arid region comprises about two-fifths of the United States; 



Three Year 

 GROVi'Tii OF Guayule 



that is to say, approximately 1,200,000 square miles or 768,000,000 

 acres. Of this, not less than 500,000,000 acres have a position, 

 altitude and precipitation that would render irrigation very ad- 

 vantageous, yet under the most favorable circumstances only 

 about 45,000,000 acres are capable of irrigation, of which 31,- 

 544,000 acres had already had water placed upon them in 1900. 



But what of the other 455,000,000 acres, not capable of irriga- 

 tion? These lands are very rich in mineral plant foods. The 

 potassium and phosphorus have not been dissolved and washed 

 away, and they have continuous sunshine during the day. On 

 such lands the guayule often grows wild and may also be culti- 

 vated, although it does not mature as rapidly as under irrigation. 

 In this respect its characteristics are peculiar. Although pre- 

 ferring a dry climate and porous, sandy soils, it endures consider- 

 able rain. Stimulated by heavy precipitation or regular irriga- 

 tion it attains a rapid, sturdy growth with large root develop- 

 ment, the latter being particularly important because the greater 

 quantity of rubber is secreted in the roots. Thus, the heavier 

 the growth the greater the crop, but, curiously enough, conditions 

 favorable to rapid, heavy growth are unfavorable to a large 



secretion of rub- 

 ber. The idea! 

 routine consists 

 of irrigation for 

 rapid growth to 

 adequate size, 

 followed by six 

 or eight months 

 of drought to 

 promote secre- 

 tion of rubber in 

 the tissues, the 

 whole covering a 

 period of four 

 years. Irrigation 

 projects for gen- 

 eral crops have 

 the objection 

 that the alkalies, 

 such as sodium 

 carbonate, s u 1 - 

 phate and chlo- 

 ride, are often 

 abundant in the 

 sub-soil of these 

 western lands, 

 and when placed 

 under irrigation 

 are brought to 

 the surface in so- 

 lution by capil- 

 larity. When the 

 accumulation of 

 evaporated alka- 

 lies reaches a 

 certain amount, 

 many crops will 

 no longer thrive, 

 but guayule will. 

 Already consid- 

 erable areas have been abandoned in this manner in every state 

 where irrigation has been practiced. Thus the claim of Courtenay 

 De Kalb that in California guayule under irrigation has been 

 known to produce as much as 28 per cent of its net dry weight 



Two Year 

 ON Ground Cut-Ovek. 



One Year 



