34 BULLETIN 87§, TJ. S. DEPARTMENT OE AGBI CULTURE. 
The better varieties of durum wheat have outyielded Marquis at 
all stations except Sheridan, Wjo., where the results are for only 
three years and are not conclusive. Of the varieties of durum wheat 
grown during the entire period of the experiments, Kubanka (C. I. 
No. 1440) has outyielded Marquis at eight of the ten stations at 
which it has been grown. It gave the poorest comparative yields at 
Akron, Colo., where it yielded only 93.6 per cent as much as Marquis, 
and the best comparative yields at Dickinson, X. Dak., where its 
yield was 121.2 per cent. Kubanka (C. I. No. 1516) has a higher, 
comparative yield than Kubanka (C. I. No. 1440) at three of the four 
stations where both have been grown. In comparison with Marquis 
the percentage of yield of Kubanka No. 8 (C. I. No. 4063) is less than 
the yield of Kubanka (C. I. No. 1440) at all stations except Dickin- 
son, N. Dak., and Archer, Wyo. At Dickinson, N. Dak., the yields 
of Kubanka No. 8 (C. I. No. 4063) have been significantly higher 
than that of Kubanka (C. I. No. 1440), but less than the yields of 
Monad. Strains of Kubanka have produced higher average yields 
than Arnautka at most of the stations. Peliss has the highest average 
yields at Havre and Moccasin. Mont., Sheridan, Wyo., and Akron, 
Colo. From these results Peliss is considered to be more productive 
than Kubanka and Arnautka in the western portions of the Great 
Plains area. Of the rust-resistant varieties of durum wheat, Acme, 
Monad, and D-5, the Acme and Monad have higher comparative 
yields than D-5, the red durum, at nearly all stations where grown, 
and are also higher than most other durum varieties. At all sta- 
tions where it has been grown, D-5 has been outyielded by either 
Acme or Monad or by both of them. 
DAYS FROM EMERGENCE TO MATLRITY. 
Notes on the dates of emergence and maturity of the varieties of 
wheat have been recorded each year at nearly all of the field stations. 
The ripening of wheat in the northern half of the Great Plains area 
occurs prematurely in most of the seasons, owing to drought, hot 
winds, or rust. In moderately unfavorable seasons the period from 
emergence to maturity is shorter and the difference in the time of 
maturity between early and late varieties is less than for the same 
varieties in a normal ripening season, such as usually occurs in the 
subhumid and humid areas. In very unfavorable seasons hot winds 
ripen, or rather " deaden," all varieties of wheat at almost the same 
time, regardless of their relative normal periods of development. 
Thus, there is a wide variation in the time of maturity of the same 
variety of wheat in different seasons in the northern Great Plains. 
The period from emergence to maturity for Marquis wheat varied 
from 72 days at Mandan, N. Dak., in 1919, to 125 days at Moccasin, 
Mont., in 1915. At Dickinson, N. Dak., the period varied from 76 
