If 



started in 1905. At present there are five large rubber 

 companies and many small plantations, with a total in- 

 vestment of $290,000. On the island of Maui alone, 

 there are 1,300 acres planted to rubber. This area con- 

 tains about 400,000 Ceara rubber trees, 23,000 Hevea, 

 and a thousand Castilloa. At first the commercial plant- 

 ings were almost entirely of Ceara; at present, however, 

 more Hevea than Ceara rubber is. being planted. A great 

 difference is observed in the width of planting adopted 

 by the different companies. In some cases, the trees 

 stand only six or eight feet apart each way, while on 

 other plantations, they may be 15 to 20 feet apart. There 

 is a growing tendency to adopt the wider planting space. 

 Formerly the opinion prevailed that rubber could be 

 treated as a forest tree, and that cultivation might, 

 therefore, be neglected. This belief, however, has proved 

 to be quite unfounded. One of the most conspicuous 

 things to be observed on our rubber plantations is the 

 greatly increased growth brought about by proper culti- 

 vation. It has been shown beyond question that in order 

 to get a satisfactory rate of growth, of either Ceara or 

 Hevea rubber, it is necessary to plow the ground and 

 give careful attention to cultivation. The recognition 

 of this fact has brought up the problem of what to do 

 with the vacant ^nd between rubber trees during the 

 first year or two of their growth. The Hawaii Experi- 

 ment Station is now carrying on experiments to deter- 

 mine the best use which can be made of the soil in rubber 

 plantations until the trees get large enough to occupy 

 the ground as an exclusive crop. For this purpose, we 

 are testing rice hay, soy beans and other legumes. 



While some income may be expected /rom crops plant- 

 ed between young rubber trees, the ultimate source of 

 revenue is, of course, looked for in the rubber trees them- 

 selves. It is impossible at present to get large areas of 

 mature rubber trees for tapping, and the preliminary 

 experiments, therefore, had to be made on trees two or 

 three years old. In these experiments, 400 trees were 

 tapped for the purpose of determining how labor could 

 best be manipulated and utilized most economically jn 

 tapping rubber trees; how expensive the collection of 

 rubber would be under our conditions; and what yield 

 of latex could be expected from Ceara rubber trees in 

 our Islands. It was found in these experiments, that 

 one laborer can tap 50 trees per hour, and can collect 

 the latex from 100 trees in the same length of time. 



