64 Wheat Rust in Australia. 



CHAPTER XIX. 

 THE PRESENT POSITION OF THE RUST IN WHEAT QUESTION IN AUSTRALIA. 



It will tend to clearness if we con-fine our attention to the rust in wheat, 

 for the general considerations which hold in this case will apply to the rusts 

 on the other cereals chiefly cultivated, viz., oats and barley. And the 

 rust which is most important from the farmer's point of view, because* it 

 does the most damage, will be chosen viz., Puccinia graminis, which is so 

 distinct in its characters that there is no difficulty in recognising, it. There 

 are only two kinds of rust in wheat in Australia, the positively injurious 

 Puccinia graminis and the comparatively harmless P. triticina, because it 

 does not pinch and shrivel the grain like the other. In the early days wheat 

 and other cereals had to be imported into Sydney, but now it is grown to 

 such an extent in the Australian Commonwealth that in the season 1903-4 

 there were 5,566,340 acres under wheat, yielding a total of 74,149,634 

 bushels. Wheat will always form one of our staple products, and from the 

 great extent of the industry, whatever increases the yield or tends to diminish 

 the losses from disease, will have a corresponding far-reaching effect. Ever 

 since attention has been given to the subject, it has been found that not a 

 year passes without its being present on wheat to a greater or less extent, 

 and in some years, which are commonly spoken of as rusty years, it seriously 

 injures the grain and considerably diminishes the yield. To give some con 

 crete idea of the extent of the loss, it may be stated that in a particularly 

 bad season like that of 1889, the loss was estimated to be for the whole o 

 Australia between ^2, 000,000 and ^3, 000,000. In such favorable years 

 for the rust, there is always an evident connexion between the weather and 

 its epidemic nature. In 1889 it was a wet spring, and about the blooming 

 season the weather was what was known as " muggy," consisting of showers 

 with heat between, and heavy dews, so that the wheat-plant, at the time of 

 coming into flower, was particularly susceptible, and the rust spores found 

 a ready entrance into the tissues of the plant, with their accumulated stores 

 of food, and thus it spread rapidly. 



Atmospheric conditions a,re often regarded as the prime factors in the 

 production of rust, but they are only concerned in the matter in so far as 

 they favour or hinder the development of the parasite which causes it, and 

 this is strikingly shown in the existence of rust-resisting wheats. Owing to 

 the importance of the subject, and the widespread losses, delegates from the 

 various States were appointed to meet and confer periodically, and these 

 various conferences extended from the first in 1890 to the last in 1896. 

 The results of their labours may be seen in their voluminous reports, which 

 practically cover the different phases of the question. But there were some 

 important points with which they were not then in a position to deal, such 

 as the effects of rust on the straw and grain, and experiments in the inocu- 

 lation of the bartberry. These will be considered preliminary to the main 

 question. 



EFFECTS OF RUST ON THE STRAW AND GRAIN. 



The visible effects of the rust on the wheat plant is well shown in PI. 



-IV., where the straw of the rust-resistant Rerraf is bright, glossy deep 

 yellow, and well ripened, while that of the badly rusted Queen's jubilee has 

 a dirty, streaky, patchy appearance. The ears of the one are full-sized and 

 well formed, with plump, well-filled grain, and the other has poor ears 

 with light and shrivelled grain. 





