B. P. I.— 401. 
A NEW BASIS FOR BARLEY VALUATION 
AND IMPROVEMENT. 
INTRODUCTION. 
In planning for the improvement of barlej crops there are among 
many other things two of great importance: (1) The means of clearly 
recognizing the best grades of barley and (2) the knowledge of what 
factors or qualities in barley ii is especially desirable to improve. 
A great many tests for distinguishing different grades of barlej 
have been in use. Of these the simpler ones, and therefore those 
thai should l>e most useful, have not been found to be reliable, ('(in- 
clusions based upon such external signs as color, fineness and wrin- 
kling of hull, smooth or toothed condition of the uerves, long or shorl 
haired basal brush, and size and shape of grain are serviceable, but 
have proved so inaccurate that it is evident the} cannot be depended 
upon as a basis for scientifically accurate conclusions. 'The test 
made h\ cutting the grain across so as to see the relative mealiness 
of it> starch contents i> also verj unsatisfactory, because there are 
two different hut similar appearing states of glassiness, one that 
injures the malting qualities of the grain, while the other has no such 
effect. Even the more difficult ami expensive chemical analyses 
leave much t<> he desired. For example. the\ indicate the percent- 
age of nitrogen contained in a sample, hut distinguish with great 
difficulty between the different kinds of nitrogenous contents; and, 
what is --till more unfortunate, though the} accurately determine 
the chemical composition of a given sample the\ have no testimony 
to offer showing why one variety has more of a certain substance than 
another, where the dilferent constituents aie located in the grain, or 
how superior grades of barlej ma\ he recognized and -till better 
grades developed. Therefore, although chemical analysis in barley 
determinations is indispensable, there is greal need for a trustworthy 
si met ural test . 
In undertaking the improvement of American barleys the Bureau 
of Plant [ndustry therefore decided to attempt the solution of some 
[Cir. 16] 
