28 BULLETIN 183, U. S. DEPAETMENT OF AGRICULTURE. 



eties arc satisfactory, even to the extent of supplying surplus malting 

 energ>^ 



The upper Mississippi VaUey is a section of high-nitrogen barleys. 

 For the most part the crop is of the small-berried 6-rowed Manchuria 

 or Oderbrucker type. It is in this region that the greatest divergence 

 of demand is felt. A majority of the malt consumers of the North- 

 west use malt adjuncts. Indeed, this custom may be said for aU 

 intents and purposes to be universal. They demand a barley of high 

 diastatic power, so as to convert the various forms of grits added to 

 the normal starch endosperm of the malt. This demand is not in 

 conflict with the facts of scuteUar secretion. The diastatic power of 

 small-berried barleys is simplj^ a matter of the shape and size of the 

 scutellum. If this power can be increased in any barley, it can also 

 be increased in Manchuria barley. A greater diastatic power would 

 allow the use of a grain with a larger starch endosperm and would 

 result in a higher percentage of extract without any loss in the desired 

 excess of diastatic energy. The Manchuria as it is sold on the Chi- 

 cago markets does vary considerably in this respect. The compari- 

 son of a good-malting Manchuria with a poor-malting Manchuria bar- 

 ley showed that in the good barley 83 per cent of the grains had a 

 scuteUum of desirable type, while in the poor barley only 1 6 per cent 

 were of this type. 



Two-rowed barleys grown in the upper Mississippi Valley are likely 

 to be much more vigorous in enzymatic action than has been thought. 

 From all the tests of the writers these barleys are shown to be of 

 rather high nitrogen content. This means that the grain possesses 

 an embryo stimulated to a growth such as would provide diastase for 

 an exceptionally large endosperm. It also means that such an endo- 

 sperm has not been developed, that much of the space in the starch 

 cells is occupied by proteid contents, and that these cells wiU be com- 

 paratively easily broken down. Such being the case, it is more than 

 probable that 2-rowed barlej^s grown in Wisconsin, Minnesota, Iowa, 

 and the Dakotas wiU be found to be able to convert a considerable 

 amount of added starch, if handled so as to develop their greatest 



efhciencv. 



MODIFICATIONS POSSIBLE BY CULTURE. 



The scope of this bulletin does not admit of a full consideration of 

 one subject intimately coimected with barley structure, namely, the 

 great changes produced by different methods of cultivation, for a full 

 understanding of this subject would involve a discussion of principles 

 of plant breeding and methods of barley farming too extensive to 

 be herein included. But at least a brief statement of the correlation 

 between the two is necessary at this point. It may be said in general 

 that efforts .to obtain by means of culture barleys of high enzymatic 



