Dec. 2, 1920.] Agricultural Gazette of y.S.W. 891 



aud is deserving of attention, as the arduous process of stubbing is not always 

 necessary or desirable. Other processes have shown themselves to be effective, 

 and certain of them would, no doubt, come into use if the prices could be 

 reduce<l to compare favourably with that of arsenite of soda, which, though 

 distributeil at cost price, cannot be regarded as a cheap commodity. 



There appears to be some uncertainty as to the pest pear in South Africa. 

 Dr. :\rarloth is quoted by Dr. Nobbs in his paper (Cape Agricultural Journal, 

 ?v"ovember, 1906) as having said that the common pest pear " is either 

 Oimntia ficus-idica or 0. tuna." The former is not a pest anywhere, and 

 what the latter species is no botanist can say with certainty. 



There is another pest known in South Africa as " jointed cactus." This 

 is known to botanists as Opuntia pu>siUa, which is another name for O. 

 aurantiaca, figured with a coloured plate in this Gazette for 1911. 



Then we come to a paper " Experiments upon the destruction of jointed 

 cactus, 1907. Final report," by Dr. Nobbs (Cape Agricultural Journal 

 March, 1902). This "jointed cactus" (Opuntia aurantiaca) was observed 

 in South Africa prior to 1874, and it is said to be " an even worse plague 

 than the prickly pear." 



This report is valuable and gives an account of spraying experiments with 

 arsenite of soda and some proprietary remedies. 



The results of the experiments, in .^reat measure, only nmfirui and extend 

 the conclusions already arrived at by the umnicipal authorities, who cleared 

 practically the whole of the commonage, wiiich two years ago was seriously 

 infested, by spraying with a 4 per cent, solution of arsenite of soda. This was 

 <lone at an average cost of £1 per morgen (a little over '2 acres) of cactus, 

 which, though itself a large sum, is yet a cheap price to pay for the reclama- 

 tion of so much valuable grazing land, which can henceforth be kept clean 

 with a minimum of trouble. 



Then an officer of the Cape Department of Agriculture reports on a 

 proprietary exterminator in the Cape Agricultural Journal, March, 1910, 

 the secret having been acquired by the Department. The method consisted 

 of making incisions in the " leaves," and inserting a iiuid poison made by 

 compounding lime and sulphur with salt and arsenite of soda. 



This cursory review of South African experience may conclude for the 

 present with the following references to departmental reports on — 



1. St. O'Gorman's Prickly Pear Exterminator (Cape Agricultural 



Journal, February, 1910). 



2. Koen and Gouw's Prickly Pear Destroyer (Cape Agricultural 

 Journal, June, 1910). 



3. Destruction of Prickly Pear. South Africa Agricultural Journal, 



November, 1911. 

 Further information in regard to South African experience will be found 

 at page 38 of the report of the Queensland Travelling Commission. 



Arsenite of Soda. 

 I have no doubt this substance has been used as a weed-killer before T 

 was born, and all that I claim is to have advocated its use for many years 

 in Australia, and I shall continue to do so (in its place) until I learn of 

 a better. 



