Notes. 481 



Numher of Birds. — The following table, showing the total 

 number of ostriches in the Union at various dates, will serve to 

 illustrate the advance of the industry between 1904 and 1913 and 

 the effect of the ensuing slump : — 



Year. 



1904 (General Census) 

 1911 (General Census) 



1913 (31st December) 



1916 (30th June) 



1918 (Census of Agriculture) 



1919* 2(^490 



Prickly Pear and Jointed Cactus Extermination. 



Eradication of jointed cactus and prickly pear has been a difficult 

 and costly problem. Both weeds grow on good soils and their destruc- 

 tion and the prevention of their spreading are most important. 



Many means for eradicating the pest have been tried. Mr. P. M. 

 Rademeyer ^introduced an exterminator several years ago, which was 

 tested but not found veiy effective. Convinced of the efficacy of 

 his preparation, Mr. Rademeyer continued experimenting with and 

 improving it, until in 1917, with the co-operation of the Agricultural 

 Department, a further test was carried out on the farm Review, in 

 the Bedford district. Two tracts of land with dense growth of jointed 

 cactus and several large prickly pear trees were sprayed on the 2nd 

 August, 1917. One portion was treated with Rademeyer's exter- 

 minator at the rate of 55 gallons per acre, diluted with luke-warm 

 water to a strength of 6 J per cent., costing at that time £4. 2s. 6d. 

 (or £2. 8s. 5d. pre-war cost). The other portion was sprayed with 

 arsenite of soda at the rate of 440 lb. per acre, diluted with cold 

 water to a strength of 5 per cent., costing at that time £22 (or £5. 10s. 

 pre-war cost). Labour and spraying operations cost an additional 

 5s. per acre for Rademeyer's exterminator, as water had to be heated 

 and applied warm to make it effective. 



The great advantage of this exterminator over arsenite of' soda 

 is that it is harmless to man and beast. The spray can be handled 

 without danger to skin or clothing; open sores and cuts on the hands 

 are not affected by the spray. A number of oxen were each fed on 

 one-third gallon of the spray mixed and well soaked with lucerne- 

 hay and prickly pear fruit and came to no harm. On the other hand, 

 arsenite of soda is poisonous to stock, and special care must be taken 

 when it is applied and the area sprayed must be fenced. 



Two and a half months after spraying (18th October, 1917), the 

 plots were finally inspected and the results found most satisfactory, 

 practically all the jointed cactus and prickly pear having completely 

 rotted on the plot treated with Rademeyer's mixture. Where 

 arsenite of soda had been used, however, a number of live cactus 



* Excluding Native Locations, Keseives, etc. 



