688 Agricultural Gazette of N.S.W. [Oct. 2, 1920^ 



Control of Liver Pltjke. 



The young liver fluke or leech must live a portion of its life in the body of 

 a fresh-water snail before it can attack sheep, cattle, goats and other sus- 

 ceptible stock, says Dr. T. B. 8imms, Veterinarian at the Oregon Agricultural 

 College. It may therefore be controlled by the destruction of snails in all 

 standing and running water to which stock has access. Regarding the 

 method of such destruction, savs this autliority, copper sulphate (bluestone) 

 added to the water in which the snails ai-e living has been found effective, 

 and solutions varying in strength from 1 part bluestone to 500,000 parts of 

 water up to as high as 1 part bluestone to 2,000,000 parts of water have 

 been found to kill all snails in less than forty-eight hours. As the treatment 

 does not destroy the eggs, however, a further treatment must be given when 

 these hatch out after an interval of two or three months. It is remarked 

 that the solution is not injurious to higher plants or domesticated animals, 

 but is possibly injurious to fish ; and that the water is not injured for bathing, 

 drinking or irrigation unless the solution is made stronger than 1 to 50,000. 



Two methods of treatment are recommended — one for standing and the 

 other for running water. In the former method the average depth of the 

 pond is first determined, and the total amount of water estimated ; then 

 suflBcient copper sulphate to make a solution of 1 to 1,000,000 is added. One 

 ounce to 1,000 cubic feet of water, or to 7,800 gallons, will do this approxi- 

 mately. If the body of water is small, the copper sulphate may be placed in 

 a sack, and the latter tied to the end of a pole and moved through the water 

 until all the bluestone is dissolved. In larger bodies of water it is a good 

 idea to tie the sack of bluestone to the stern of a boat, rowing the latter 

 around the pond until the contents of the ."^ack are dissolved. 



Running water can also be treated, but the method is rather complicated. 



Immature Potato Seed. 



Immature potato seed is best described as the potatoes from a late sown 

 ci'op, which, through being frosted, have not been given time to develop 

 fully, or as those obtained by digging an earlier sown crop before it had 

 ripened off. It is for the former reason that potatoes from the tableland 

 districts are better suited for seed purposes in the coastal areas than the locally 

 grown produce. — A. H. E. McDonald, Chief Inspector of Agriculture. 



Increased Production op Wool per Head of Sheep. 



That the pastoral industry in Australia is a live and growing thing, and 

 that a very positive improvement has been effected in the production of avooI 

 per head of sheep, the appended figures show : — Whereas in the period 

 1890-1893 there were 60,000,000 sheep, with an average weight of wool per 

 bead of 3 lb. 9 oz., in the period 1900-1903 there averaged 36,000,000 

 sheep, with a weight of wool per head of 6 lb. 3 oz. Finally, in 1916-19, 

 there averaged 35,000,000 sheep, with a weight of wool per head of 8 lb. 

 7 oz. This means that in 1918-19, with 25,000,000 less sheep, there 

 were 70,000,000 lb. more wool produced than in 1S91.— J. Wrenford 

 Mathews, Sheep and Wool Expert. 



