CEREALS 367 



been durum wheat, this loss would have been entirely 

 avoided." 



Orange leaf rust {Puccinia tritidna Eriks.)-- — This is the 

 most common and widely distributed of all rusts of the 

 United States. It is said by Carleton that it is not only 

 never absent from the wheat fields throughout the year, 

 but that it is sometimes abundant even in dry seasons. 

 Though it is so abundant, its inroads upon the crop are 

 not usually serious, and in no case on record has it caused 

 shriveling of the grain such as is common from the black 

 stem rust. 



The most conspicuous feature of this rust is the abundant, 

 orange-colored sori upon the leaves, especially upon their 

 lower surfaces. The grayish black teleutosori are neither 

 so prominent nor so abundant as in the black stem rust. 

 Both of these rusts possess the uredo stage, and it is difficult 

 for any but the expert to distinguish them apart in this 

 condition. 



As with the rye orange leaf rust, this fungus also can winter 

 its live uredo mycelium and continue to bear uredospores 

 throughout the year, spending its entire existence, if neces- 

 sary, in this one stage upon the single species of host. 



While no variety of wheat is entirely proof against it, 

 large difference is shown in thic respect, some varieties 

 presenting high resistance, even under most adverse condi- 

 tions. Early maturity is an important factor in evading 

 rust. 



The following standard varieties are recommended by 

 Carleton as possessing considerable resistance to the orange 

 leaf rust in every part of the country — " Winter wheats : 

 Turkey, Mennonite, Pringles No. 5, Rieti, Odessa, Pringles 



