180 ESSAYS ON WHEAT 



Professor W. P. Thompson is st\id_ying the problem of 

 rust-resistance with a view to a solution of it for this 

 country in the near or distant future. Up to the present, 

 however, the greatest contribution to the task of combating 

 Eu'st in Canada has been made by Dr. Saunders through 

 the introduction of early-maturing Marquis wheat. The 

 losses to the wheat crop through Black Stem Eust in the 

 year 1916 were about 100,000,000 bushels in Canada '^ 

 and 140,000,000 in the United States ; ^^ and, doubtless, 

 they would have been considerably greater, had not Mar- 

 quis with its early ripening habit already by that time so 

 largely supplanted later-maturing varieties such as Eed 

 Fife and Bluestem.^* 



XIY. Earliness and Frost 



Owing to its earliness, Marquis is less Ijable than Eed 

 Fife, etc., to be injured by early frosts in the colder sec- 

 tions of the wheat-growing area. In the greater part 

 of the southern and central prairie region of Alberta, 

 Saskatchewan, and Manitoba, the first destructive frost 

 usuall}^ occurs between September 6 and September 12. 

 In this region. Marquis, and usually also Eed Fife, ripen 

 their grains sufficiently early to escape this frost. Fur- 

 ther north, the first destructive frost frequently occurs 

 from August 27 to September 2. In this region. Marquis 

 usually ripens early enough to escape the frost, but Eed 

 Fife often suffers from it very severely. Still further 

 to the north, and in less favored districts, the first de- 

 structive frost comes from August 20 to August 26. This 



42 Estimate made by the writer from a study of data collected 

 by the Secretary of the Winnipeg Grain Exchange. 



43 Estimate kindly sent to the writer in a letter by M. A. Carle- 

 ton, cerealist for the U. S. Department of Agriculture. 



44Bluestem ripens later than Red Fife, and is therefore very 

 little grown in Canada, though well known in the U. S. A. 



