174 CORDAGE FIBRES 



2,700 lb. ; and a yield of at least a ton per acre may 

 therefore be anticipated. 



As the result of actual trials carried out at Punda 

 Milia, it was found that 91 2 leaves, weighing 2, 2 63 lb., 

 or an average of 2-48 lb. per leaf, yielded 52 J lb. 

 (2*32 per cent.) of dry, brushed fibre, equivalent to 

 about i lb. of fibre from seventeen leaves. The 

 plants from which these leaves were cut were spaced 

 8 feet x 8 feet, this arrangement giving 68 1 plants 

 per acre. Taking 1 60 as the average number of leaves 

 produced per plant during its life, the total yield per 

 acre, when calculated by means of the above figures, 

 is 6,240 lb., or a little less than 3 tons. As the plant 

 lives at Punda Milia for about three years after the 

 first leaves are ready for cutting, these observations 

 are in agreement with the estimated yield of one ton 

 per acre per annum given in the preceding paragraph. 



Duration of Life of the Plant. As has been already 

 stated, the duration of life is determined by the 

 production of the pole or inflorescence. In Mexico 

 the plants are said to live for fifteen or sometimes 

 even twenty-five years before poling, whilst in more 

 tropical countries they live a much shorter period, 

 the average length of life in German East Africa 

 being only about six years. In general, the duration 

 of the plant appears to be largely dependent on 

 conditions of soil and climate. It has been asserted 

 that the life may be prolonged by cutting out the 

 pole as soon as it appears above the leaves, the plant 

 being thus rendered available for fibre for nearly a 

 year longer than it would be otherwise, but experi- 

 ments which have been conducted in German East 

 Africa do not support this view. The early poling 

 of Sisal plants in East Africa has been much discussed 

 and has been regarded by some planters as a great 

 disadvantage. It appears, however, that the com- 

 paratively short life is due to the fact that there are 

 two growing seasons in this country, and growth is 

 checked twice a year, whereas in less tropical countries 

 there is only one growing season per annum. Thus 

 it is evident that the plant in East Africa lives through 

 approximately the same number of growing seasons 



