204 



Guayule. 



The probable necessity of transplanting large numbers of seedlings 

 at a very great risk of loss led me to adopt experimentally a scheme used 

 in the tropics, where the hollow joints of bamboo are used as flowerpots 

 in which to raise cacao, coffee, and other seedlings. When ready for plant- 

 ing in the grove the whole pot is planted, and the decay of this, aided by 

 fracture, sets the roots free without any disturbance. In a preliminary 

 way the joints of "carrizos" (Arundo donax) were tried, but proved too 

 small. Combining this idea with that of the paper flowerpot, a unit sys- 

 tem of wooden trays and paper tubes was devised, 1 the tubes being i 

 square inch in transverse section and 6 inches long (plate 45, fig. A). As 

 trials with these taught that they afforded too little room for the horizon- 

 tal development of roots, a comparative test with similar tubes of 4 square 

 inches transverse section was carried out under identical conditions. A 

 tray 20 by 28 inches inside measure and 6 inches deep was filled with 

 these tubes (plate 45, fig. B), the whole being filled with unsifted limestone 

 soil in which there were a great many small fragments of caliche and 

 stones. The tray was placed in a melga and watered by subirrigation. The 

 surface was shaded at a height of 4 cm. by a thin cotton cloth supported 

 in a frame. The shade was raised or lowered as the surface appeared to 

 need more or less air, so as to check the growth of fungi (a Coprinus sp. 

 was very frequent in the decaying paper of the tubes) , among which one 

 species, at least, caused damping-off. On February 16, 1908, 1.5 ounces 

 of seed were sown. The germinations were as shown in table 56. 



TABLE 56. 



The appearance of these seedlings is shown in plate 45, figs. C, D, from 

 which it will be seen that a good, fairly even stand of sturdy seedlings 

 (plate 46, fig. A) was obtained. The size of the tubes used was, of course, 

 a compromise, but fig. 19, A, shows that a sufficiently satisfactory root- 

 system can grow in them, though of course by no means as good as when 

 the roots have normal freedom (fig. 19, B), which in any case is neither 

 desirable for practical purposes nor expected. The tray held 140 tubes, 

 from which it is seen that there was an average of about 3 seedlings to the 

 tube. The unevenness was due to the removal of seed from its original 

 position by rain or occasional surface-watering, which is desirable to aid 

 in preventing too rapid caking of the surface. To prevent this movement 

 of seed the surface should be as level as possible. The margin of the tray 



By Capt. L. C. Andrews. 



