551 



ever, is startling. Professor Biffen, in his essay on M Systema- 

 tised Plant Breeding,"* writes with regard to this disease "what 

 this (toll) amounts to on the average it is impossible to say at 

 all definitely, but an estimate of from 5 to 10 per cent, is 

 probably not very wide of the real figures." Applying even the 

 lower figure to the year 1919, when 2,370,307 acres were under 

 wheat, the amount lost by Yellow Rust (at an average of 

 4 quarters per acre) would be over 450,000 quarters. An allow- 

 ance, however, must be made for resistant varieties. 



The fact which every farmer should realise is that this loss 

 oj crop is largely preventable. There exist some good wheats 

 which are very suitable for use in this country and are highly 

 resistant to Yellow Rust. By the growing of these wheats the 

 fungus is outwitted and the crop benefits in proportion. The 

 three wheats resistant to Yellow Rust are "Little Joss," 

 " Yeoman," and " Swedish Iron," the first two being raised by 

 Professor Biffen at Cambridge. Unlike the susceptibility of 

 potatoes to Wart Disease, where certain kinds are absolutely 

 immune, these wheats sometimes show, specially early in the 

 season, traces of Rust. They are, however, highly resistant, and 

 always stand out in striking contrast to other sorts. No specially 

 resistant spring wheat has yet been raised. In all districts 

 where winter wheat is grown and Yellow Rust is prevalent, one 

 or other of these varieties should be tried. Notes on their 

 characters and their suitability for different areas are given 

 below. Further advice may be obtained from the local 

 Agricultural College. 



" Little Joss." — An excellent all round, red wheat of good 

 quality ; it tillers freely and matures early. It is particularly 

 suitable for light and poor soils, late districts and exposed situa- 

 tions, but is not good for land which is cold and wet in winter. 



Yeoman is a new wheat with short, stiff straw. It 

 possesses high-yielding and first-class milling properties, and 

 can be grown on almost all classes of soil. It does extremely 

 well south of the Thames. 



* " Swedish Iron " is a stiff-strawed, large-grained wheat 

 suited for good land in a high state of cultivation. It does well 

 in the north and cooler parts of the country. 



Black Rust. — Puocinia graminis, the Black Rust fungus, is 

 without doubt by far the most serious of all wheat parasites. This 

 is this fungus which causes the devastating epidemics in India. 

 Australia, and America, and it is, in fact, liable to occur in 

 epidemic form in any country where - it exists. As an example 



* " Science and the Nation," Cambridge, 1917. 



D 2 



