xvn. 



production of a large amount of fruit from small areas, e.g., about 10 tons per 

 acre, and also some rapid method of collecting the fruit. It may be added 

 that the pest pear of ^he Burnett Valley is especially prolific in fruit. 



Investigations in Italy, where the fruit of 0. ficus indica was used, 

 showed that Saccharomyces opuntice, the yeast ordinarily associated with it, sets 

 up a slow and incomplete fermentation, but if another ferment, 8. pastorianus, be 

 allowed to operate on sterihsed must, complete conversion takes place. However, 

 the extra cost involved in sterilising was regarded at the time as being a serious 

 hindrance to commercial success. Later investigations have, however, over- 

 come this difficulty. 



Still it must be mentioned that potable spirit, not raw alcohol, was the 

 article manufactured commercially from this prickly-pear fruit, notwithstanding 

 the fact that in those countries it has considerable market value as an edible 

 product. In Queensland, on the other hand, the fruit at present has no 

 marketable value, but is a waste product. Accordingly, if alcohol could be 

 produced from it, such action would probably lower the cost of eradication. 

 We, therefore, recommend that investigations be carried out in our own State, 

 especially since some of our commoner pest species are prolific in fruit production. 



E. Utilisation of the Fibre. 



Some years ago paper-makers examined samples of the fibre of 0. dillenii 

 from India, and considered the material valueless for their purposes when 

 compared with other equally plentiful materials. 



As a result of most methods of destruction employed in this State, the 

 woody tissue of the plant is left intact, and it was recognised that if this fibre — 

 a by-product — possessed any value, then the cost of clearing infested land could 

 be correspondingly decreased. Therefore, paper-pulp manufacturers and paper 

 technologists were interviewed, and their opinion sought regarding its possible 

 utilisation in the manufacture of the various cruder kinds of " boards," e.g., 

 roofing boards, millboards, leather boards, trunkboards, strawboards, &c., 

 rather than of paper proper ; and even floor-cloths might be mentioned in this 

 connection. 



It was ascertained that the shortest fibre used for paper proper was that 

 of esparto, and that any shorter fibre could be employed only as a filling material, 

 and even for that purpose only if its cost were very low. 



American plants are stated to have an average of 84"3 per cent, water 

 and 2*4 per cent, of crude fibre, and the latter, yielding about 42 per cent, of its 

 own weight of dry pulp, so that about 100 tons of green plant would be needed 

 to produce one ton of pulp of low quality, worth not more than a few pounds 

 per ton. 



The Imperial Institute, London, carried out some investigations con- 

 cerning the common pest pear of New South Wales and Queensland, and reported 

 that its fibre, which has an average length (0*029 inch), only a little more than 

 half the average for esparto grass (0'045 inch), is readily converted into a dark- 

 brown pulp, from which a coarse paper of poor strength may be made. It was 

 considered that it would not be remunerative to produce the pulp in Queensland 

 for export, and it was regarded as being unlikely that it could be profitably 

 used locally even in admixture with materials of better quality, though this 

 could only be decided by actual trials on the spot, and a consideration of the 

 resvilts in connection with the prices of chemicals and labour in Queensland. 



