20 



BULLETIN 137., U. S. DEPARTMENT OF AGRICULTURE. 



gence of the awns of the three being identical. The records show 

 that the emergence was also on the same date the previous year. 

 No. 55 is proved to be distinct by the nature of the rachilla, but the 

 date of heading, time of stooling, etc., are parallel in JSTos. 3 and 6, 



and there is little doubt that they 

 are identical. 



While not pertinent to this 

 phase of the discussion, the 

 curve of density and the curve of 

 emergence of beards are almost 

 opposite in the Manchuria bar- 

 ley. In other words, there seems 

 to be a direct correlation be- 

 tween density and earliness. In 

 figure 14, in which are assembled 

 a number of other types of 6- 

 rowed barleys that are for the 

 most part not closely related, 

 this is not true. 



The first five selections, the 

 densities of which are shown in 

 figure 14, are from a commercial 

 variety known as Odessa. This 

 so-called variety seems to be a 

 loose assemblage of widely varying types, which are, however, ones 

 not common in other 6-rowed barlej^s. The component strains are 

 not nearly as closely related as are those of the Manchuria. That 

 this variety itself is of hybrid origin or that there has been crossing 

 between its members 

 is indicated in figure 

 15. This selection, the 

 most dense of those 

 made from the Odessa 

 variety, proved un- 

 stable. The number 

 of plants bearing 

 ' dense heads was 71, 

 as opposed to 16 for 

 the looser ones. 



While a character 

 need not be invariable 

 under all conditions in 



order to be useful, a test was made to discover the effect of soil and 

 climate on density of spike. Six selections were planted at St. Paul, 

 Minn., at Chico, Gal., and at Aberdeen, Idaho. At Aberdeen they 

 were grown both under irrigation and upon dry land. The measure- 



S 9f 97 3/ 



Fig. 14. — Curves showing the average 

 density and the date of emergence of 

 the awns in 12 miscellaneous selections 

 of barley grown at St. Paul, Minn., in 

 1913. 



;:• 30 



I 



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/ 



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2 



V ■ 



i £ 



j £ 



? a 



f 2 



9 J 



? 3 



' 3, 



otr, 



3 3 



C 3- 

 r/£-_ 



3 



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Fig. 15- 



-Curve showing the density of 134 



spikes 



of 



Odessa 



(No. 9) barley grown at St. Paul, 



Minn., 



iO 



1913. 









