Aprils, 1920. J Agricultural Gazette of N.S.W. 266 



St. John^s Wort and its Effects on Live Stock* 



SYDNEY DODD, D.V.Sc, F.R.C.V.S., Veterinary Pathological Laboratory, 



University of Sydney. 



The spread of St. John's Wort and the danger threatened to the pastoral 

 and agricultural interests in the localities affected, has lately been the subject 

 of considerable correspondence in the press and discussion amongst farmers 

 and graziers. I am informed that the Federal Bureau of Science is making 

 inquiries as to the advisability of introducing insect enemies of the plant ; 

 but it would appear that with the exception of one district in New South Wales, 

 the evil is still regarded as a negative one, and St. John's Wort is still 

 viewed purely as a weed— that is, as an undesirable plant the economic 

 value of which is low or nil, but which, by virtue of certain characteristics, 

 is able to crowd out more profitable growths. 



With the exception of some of those in the locality referred to, graziers 

 seem to regard the plant merely as a nuisance. Those excepted, however, 

 have been taught by first-hand experience that St. John's Wort is more than 

 that. They know that eaten by stock it may, under certain conditions, 

 produce very profound disturbances to health — perhaps not very frequently 

 ending in death, but seriously aflPecting the value of the wool in the case of 

 sheep and the hides and milk in the case of some cattle. In both sheep and 

 cattle the value of the carcase suffers on account of the loss of condition, &c. 



It is with the object of bringing forward this aspect of the question that 

 the writer has conducted experiments with the plant and collected information 

 concerning its action in this State. 



Other Records of the Plant's Ill-effects. 



For a botanical description of St. John's Wort, the reader is referred to an 

 article by Mr. J. H. Maiden in the Agricultural Gazette, Vol. xxviii, part 6, 

 p. 413. At present the plant occupies a relatively small area in the State, 

 and vigorous action — not the mere discussion of what should be done and 

 the passing of regulations without doing anything further — should check 

 its spread (if not completely eradicate it) at a cost which would be small 

 compared with the increasing losses sustained by depreciation of the market 

 value of the infested land, and the injury to live stock wherever the weed 

 gains a foothold. In the district referred to in this article, the writer is 

 informed that the plant has been officially declared a noxious, weed and 

 nothing further has so far been done. It should be recognised, however, that 

 the task of getting rid of the plant is by no means a simple one. Burning 

 off' or mowing appears merely to stimulate it to more vigorous growth, while 

 (as anyone who has seen the root system of an old plant will realise) a 

 single ploughing or hoeing up, and then nothing further, is only waste of 

 .time and labour. 



