60 BULLETIN 618, U. S. DEPARTMENT OF AGRICULTURE. 



(2) No spring wheats do well in the southern part of the Great 

 Plains. 



(3) Wherever the hard rod winter wheats of the Crimean group 

 can be grown commercially they are better yield ers than any spring 

 wheat. In the higher and drier parts of the plains of Colorado and 

 Wyoming and in central South Dakota their advantage is very 

 small. 



(4) In the central and northern .parts of this area, wherever 

 spring wheat is commercially important, durum exceeds spring 

 common wheat in yield almost without exception. Usually this 

 is by a large margin, of 10 to 30 per cent, but occasionally by as little 

 as 5 per cent. 



(5) Of all the varieties of durum wheat tested in this area, the 

 Kubanka is best adapted to all the varying conditions. It is most 

 suitable for central and western North and South Dakota and 

 eastern Montana, at altitudes ranging from 1,800 to 4,000 feet. 

 The Arnautka is slightly better adapted to the more humid eastern 

 part of the Northern Plains with altitudes ranging from 1,000 to 

 1,800 feet. The Pelissier is a better } T ielder in the western and drier 

 sections at altitudes of 4,000 to 6,000 feet. 



(6) A number of pure-line selections of durum wheat are proving 

 better adapted to the local conditions where they were developed 

 than are the older standard varieties. Three which differ appre- 

 ciably from the standard varieties from which they were selected 

 have been named. Five of these races appear to be of sufficient 

 value to be tested under a wide range of conditions. They are as 

 follows: Acme (C. I. No. 5284), a selection from Kubanka (C. I. No. 

 1516) made at Highmore, S. Dak.; Arnautka (C. I. No. 4064) a selec- 

 tion from Arnautka (C. I. No. 1494) made at Akron, Colo.; Monad 

 (C. I. No. 3320), a selection made from a field in Russia but tested 

 at Dickinson, N. Dak.; Buford (C. I. No. 5295), a selection from 

 Taganrog (C. I. No. 1570) made at Williston, N. Dak.; Kubanka No. 

 8 (C. I. No. 4063). a selection from Kubanka (C. I. No. 1440) made 

 at Dickinson, N. Dak. Of these five, Acme and Monad are very 

 rust resistant. 



THE ARID BASIN AND COASTAL AREAS. 



A study of the data from the six stations located in these western 

 areas, as summarized in Table XXXIII, shows two facts definitely. 



(1) Except for the Crimean group of winter wheats, the standard 

 varieties of the western areas differ from those of the Great Plains 

 and Prairie States. 



(2) In these areas the better yields have been obtained from 

 hard red winter wheats of the Crimean group or from some variety 

 of soft white wheat. 



