FIBER PLANTS 183 



cut, dried, and then retted for 4 or 5 days in water. Sunn 

 hemp is also a valuable cover crop and is extensively grown as 

 a green manure plant. The quantity of foliage and vegetable 

 material produced per acre, however, is less than with several 

 other species of Crotalaria. About 500,000 acres of sunn hemp 

 are grown from fiber in Madras, where the fiber is produced 

 as a substitute for jute. The fiber is really better than jute 

 and of a lighter color. 



PINEAPPLE FIBER 



Pineapple fiber is produced chiefly in the Philippine Islands, 

 Formosa, and Java. In the Philippines this fiber is used in 

 the manufacture of the well known pina cloth, while the fiber 

 produced in Formosa is shipped to China, where it is made into 

 grass cloth or grass linen. For fiber, pineapple plants are spaced 

 4 by 4 feet. The yield is about 500 pounds of fiber per acre. 

 Ordinarily the leaves contain 3 or 4 per cent, by weight of 

 fiber. In the Philippines and Formosa the fiber is removed 

 from the leaves by hand. In order to obtain the best quality of 

 fiber it is necessary to harvest leaves at their maximum stage 

 of growth and before they begin to wither at the tip. The 

 Hawaii Experiment Station made a study of the possibility of 

 utilizing pineapple leaves from commercial pineapple planta- 

 tions in the production of fiber. In Hawaii, three crops of 

 pineapples are taken before the fields are replanted. Most of 

 the leaves of the old plants have therefore begun to wither at 

 the tips before the three crops of fruit are harvested. A ton of 

 these leaves was collected and put through an ordinary sisal 

 decorticator. An excellent quality of fiber was obtained with- 

 out difficulty. It was found that the leaves yielded about 3 per 

 cent, by weight of commercial fiber. Considerable loss of fiber 

 occurred for the reason that the sisal decorticating machine 

 was not quite properly adjusted for pineapple leaves. Fiber 

 obtained from old pineapple leaves under such circumstances 



