DISEASES OF WHEAT 169 



as a rule, somewhat dwarfed, are close and compact, and stool 

 but little. The leaves, comparatively few in number, are stiff, 

 narrow and erect, with a more or less tough, dry cuticle, often 

 with a glaucous or waxy surface; heads compact and narrow; 

 and grains hard, red, small and heavy/ 7 



Varieties likely to prove considerably resistant to rust in the 

 United States, if they are sown early, are, Kharkof, Turkey, 

 Mennonite, Pringles No. 5, Rieti, Odessa and Pringle's De- 

 fiance for winter wheats, and Haynes Blue Stem and Saskat- 

 chewan Fife for spring wheats. 



Durum wheats are much more resistant than other varieties. 

 During the great rust attack of 1904 in the northwest, the 

 maximum loss for durum wheat seems to have been about 10 

 per cent while that of ordinary wheats was frequently as great 

 as 50 per cent. The different varieties of durum wheat also 

 vary in their power to resist rust, two of the best being lumillo 

 and Velvet Don. "Rerraf" is one of the best rust resisters in 

 Australia, but is quite non-resistant in the United States. 



Other Diseases. Leaf blight (Septosphaeria tritici Pass.) and 

 Powdery mildew (Erysiphe graminis D. C.) occasionally cause 

 slight losses in certain sections. 



1 Carleton, Cereal Rusts of U. S., p. 21. 



