10 



BULLETIN 131, U. S. DEPARTMENT OF AGRICULTURE. 



and yet it is among the very latest in maturity. Indeed, there is 

 some peculiarity about each one of the fourteen when all stages are 



considered. 



VARIATIONS IN THE CULM. 



The culm varies in length, diameter, thickness of walls, exsertion 

 of spike, number of nodes, and number of culms per plant. 



LENGTH OF THE CULMS. 



The height of the plant is a note, universally taken on all experi- 

 mental farms. At any chosen station, some varieties are always tall 

 f «i — | — | — i — | — i — | — [ — i — i — | — i — x^\ and others always short. This 



distinction is sufficient to prove 

 a difference between such va- 

 rieties, and as such it is a use- 

 ful observation in breeding. 

 It is, however, merely a proof 

 that a difference exists and is 

 not necessarily a difference in 

 itself. There is a physiologi- 

 cal adaptation of varieties to 

 certain places and it may ex- 

 press itself in height. 



In 1911 thirteen pedigreed 

 selections, representing nine 

 minor groups of barley, were 

 chosen from the nursery stock 

 and planted at four widely 

 separated points. At maturity 

 the length of culm was care- 

 fully noted. The influence of 

 climate and soil was surpris- 

 ingly great. As will be seen in 

 Table I, there is a marked re- 

 gional response. The selection 

 of Odessa is a Hordeum sati- 

 vum hexastichum form occur- 

 ring in the commercial Odessa 

 variety. In Minnesota it is 

 short and unpromising. In 

 California it is little better, 

 while in the north Rocky 

 Mountain and Plains areas it displays an unexpected vigor and is 

 very tall. The Abyssinian varieties grow well in California, but are 

 short elsewhere. 



































































































































































































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SEC£CT/o/v A/uMggPS or fufNTS. 



Fig. 7. — Curves showing the date of the 

 production of the second, third, and 

 fourth leaves and the first tiller, the 

 emergence of the awns, and the day 

 of ripening in 14 selections of barley 

 grown at St. Paul, Minn., in 1913. Each 

 determination was based on one centgener 

 of approximately 100 plants. 



