Flag Smut of Wheat. 89 



History. 



The earliest record I can find of the prevalence of this disease in Australia 

 is contained in the Eeport of the South Australian Commission on Diseases 

 in Cereals in 18G8. There it is unfortunately referred to under the name of 

 " Black Kust," and even at that period it is spoken of as a disease with which 

 the farmers were familiar. 



In New South Wales Dr. Cobb^ had referred to it in 1891 as behig a 

 serious plague, and remarked that " It is not rare for half the crop to be lost 

 through its ravages, and a loss of 10 per cent, is common." In 1892 I first 

 reported upon it at Kochester, in Victoria, where it had been prevalent for 

 some time, and had caused considerable loss. 



On making mquiries as to its occurrence in Queensland, I am informed by 

 the Government Vegetable Pathologist there that only a single instance of it 

 had come under his notice in 1906 in a wheat crop grown in the heavy soil of 

 the Hodgson district. However, this does not imply that the disease was 

 confined to this one spot, for he significantly adds — " that it may have been 

 more prevalent than is indicated by this statement, since farmers are not in 

 the habit of calling attention to affections in their crops until these are 

 sufficiently pronounced to cause them some concern." In West Australia and 

 Tasmania there is no record of it so far. 



This disease was at first only known on wheat in Australia, but now it 

 has been recorded on wheat in Japan in 1895 by Hori\ and on wheat in India 

 in 1906 by Sydow and Butler. ^ 



Origin. 



Although this smut first appeared, as far as known, on wheat in Aus- 

 tralia, it does not necessarily follow that it originated here. It is always 

 difficult to trace the early beginnings of a particular disease, especially after 

 it has become rather widely distributed. It may have been introduced into 

 Australia through the medium of the seed or chaff of rye, and particularly 

 into South Australia where there are a number of German settlers. Mr. 

 Summers, of the Agricultural Department, Adelaide, has kindly made in- 

 quiries, and informs \wq that it has long been customary for settlers on the 

 hills to grow small plots of rye for early green feed. Once introduced, this 

 smut might adapt itself to the wheat plant, in the absence of its regular host- 

 plant — the rye — in sufficient abundance, and in such an extensive wheat- 

 growing country as South Australia its spread would be only a matter of 

 time. This, however, is only a surmise, as there is no record of smut on 

 the rye. It is hardly necessary to do more here than refer to the popular 

 notion that all smuts are practically the same, no matter on what plant they 

 occur, and that the flag smut of wheat may easily have Leen derived 

 Irom one of the others. It is quite possible that fag smut of 

 wheat may have been derived from rye smut, which also occurs, 

 although less frequently, on oats and barley, as it is closely allied 

 to it in structure and habit, but that is something very different from 

 saying that one smut may arise indiscriminately from another, even when 

 they are as distinct in their structure and life-history as stinking smut and 

 flag smut. There is another point worthy of consideration in regarding 

 this smut as having probably been derived from that of rye, and that is the 

 close affinity between the two host-plants. Eye is said to be more closely 

 related to wheat than any other cereal, although differing in several par- 

 ticulars, and the same rust has beeii found on it, viz., Puccinia gmminis, 

 Pers., which Eriksson found to produce aecidia on the Barberry, just as in 

 the case of wheat. 



