104 MOZAMBIQUE 



From these data we can make the following 

 computation : — 



2 metres of dry stem weigh 1 kilo 



1 plant (20 metres) will weigh (di-y) ... 10 kilos 



80 plants (1 hectare) ,, ,, ••• 800 ,, 



800 kilos of wood will yield 3 per cent, rubber 24 ,, 



24 „ of rubber at 8s. per kilo 192 shillings 



1 hectare of Landolphia forest will yield 



24 kilos of di-y rubber valued at £9 12s. 



Compare this with the return from a plantation 

 of Ceara rubber : — 



1 hectare planted 12 feet by 12 feet contains... 745 trees 

 745 trees at 10 trees per kilo of rubber gives ... 74 kilos 

 74 kilos of rubber at 8s. per kilo ... ... 592 ,, 



1 hectare of Manihot Galziovii will yield 74 

 kilos of rubber valued at £29 12s. 



In the one case you have to wait fifteen years 

 for a gross return of £9 12s., in the other one 

 year for a gross return of £29 12s. 



The probability, nay certainty, is that fifteen 

 years would find a material reduction in the 

 number of vines per hectare, because Landolphia 

 requires a certain amount of light and will not 

 thrive in dense forest, but the tendency of a 

 closed forest would be to become dense and 

 dark. If the forest is to be planted up with 

 new vines, then the young plants must be looked 



