Dec. 2, 1920.] Agricultural Gazette of N.S.W. 



889 



Chats about the Prickly Pear. 



i\o 7. 



J. H. MAIDEN, I.S.O., F.R.S., F.L.S., 

 Government Botanist, and Director, Botanic Gardens, Sydney. 



The Use of Poison and Poisoning Apparatus. 



This aspect of the subject may be approached under the following 

 headings : — 



South African experience. 



Arsenite of soda. 



Other poisons. 



Gas {msenious chloride). 



High-pressure steam. 



Apparatus — Rollers, sprayers, injectors. 



The Scone experiments of 1907-8. 



Subsequent experiments. 



A Competition suggested. 



South African Experience. 



While there is a difference of opinion as to the economic value to the ' 

 Australian stockowner of some kinds of prickly pear, there is no difference 

 of opinion as to the desirability of having the destruction of species, 

 especially the pest pear, as a principal end in view. I propose to give a 

 brief outline of prickly pear destroyers. 



In this Gazette for September, 1898, will be found valuable information 

 in regard to pear destroyers, chiefly based on the experience of Mr. A. C. 

 MacDonald, who conducted experiments for the Department of Agriculture 

 of Cape Colony. 



The advice there given to use arsenite of soda has been repeated by me 

 to many persons during the last twenty-two years, and I believe it to be 

 good advice on the whole. 



In the Cape of Good Hope, experiments of a valuable character have 

 been going forward ever since, and we can learn much from the experience 

 of our South African friends. 



In the Cape Agricultural Journal for 30th March, 1899 (Vol. XIV, . 

 p. 471), the Government regulations are stated for the free supply of 

 " scrub exterminator for eradication of prickly pear " to owners or occupiers 

 of land on which prickly pear is growing. 



The result of supplying the exterminator free is thus stated: — 



If there was ever a champiou nest of prickly pear, exliibiting all the worst 

 features of these over-run areas, It would be, perhaps, Cookhouse, ou the 

 Great Fish River. Mauy spasmodic efforts have been made to clear small open _ 

 pa,tehes close to the drift, but most of these efforts were made simply by 

 mechanical means, and with no intention to push the clearance beyond the 

 immediate necessities of a garden. With the exterminator, however, and urged 



