200 Guayule. 



In the Lomerio de Zorrillos, some leagues further south, where the 

 substratum is made up of fine limestone soil containing stones of various 

 sizes, it is easy to pull the plants up, and here all the larger ones were 

 taken. As the number of small plants was, however, very great, all these 

 were left, and number 600 to 800 to the 100 square meters, weighing i to 2 

 tons to the hectare. This condition probably represents the best that may 

 occur under the old methods, and is but seldom found. In many spots 

 from which larger plants had been taken, pieces of root left by breaking 

 off were found to have produced retonos. 



The work of pulling up the guayule is done by peons who tie the shrub 

 into bundles, make up burro-loads, and take it to a neighboring " campo de 

 guayule," a field-center of operations, where the shrub is baled in hand- 

 presses. From here it is hauled in wagons to the most accessible shipping- 

 point on the railroad, and so by rail to the factory. 



In undertaking to harvest the shrub from a particular region, the 

 usual method is to let a contract to local agents who can command the 

 conditions, which, as may well be imagined, are often severe on account 

 of the great distances and lack of water. The easiest time to work is 

 while the ground is still soft from the rains and when water is relatively 

 plentiful, and it happens that this is the worst possible time to take the 

 plant as regards its rubber- content. At that time also the shrinkage in 

 weight is much greater, both by the loss of a greater amount of water in 

 the plant and the larger bulk of the foliage. 



SUGGESTED RULES OF PRACTICE. 



The statement will not need defense that an immediate desideratum 

 is a rationale of forestal operation, in order that the present field supply, 

 already much reduced from the original stand, may be kept from being 

 well-nigh wiped out. The data upon which rules of procedure. must be 

 based, in the absence of still necessary extensive quantitative study of 

 treated areas, have been presented in Chapter IV. The general practice 

 indicated by the experiments recorded will therefore be stated here. 



1 . Guayule should be gathered by cutting it off at the level of the 

 ground. That which is allowed to project above the surface will die back 

 more or less and be an economic loss, as these parts represent a substan- 

 tial proportion of the weight of the plants. The cutting should be done 

 with a sharp grubbing-hoe (talacho) , a method which is easier on the men, 

 as well as contributing to the preservation of the stand of plants. It is 

 practically certain that new shoots will arise from many of the parts left 

 in the ground, and these, during the first season, will produce flowers, the 

 seeds from which will help to repopulate the area. 



It has recently been suggested by Escobar (1910) that, after cutting, 

 a shallow depression be cut in the soil about the remaining root, for the 

 purpose of catching the run-off, thus increasing the water-supply. Further 

 operations (terracing or furrowing along the contour lines) , designed to 

 hold back the run-off, are also recommended. In many situations it 

 would be difficult to carry out schemes of this kind. 



2. Only plants 40 cm. or more in height should be taken on the first 

 cutting. Five years later there should normally be a crop of 40 cm. plants, 



