528 CULTIVATED WHEATS 



while in wet localities the straw is abundant, but the grain poor 

 in amount and quality also. 



Varieties are met with capable of giving good y ields upon 

 almost all soils except those of the lightest class or stiff, wet 

 clays ; the soils, however, best suited to growth of the most 

 valuable wheats are stiff clay loams. 



Sowing. — Winter wheats are sown in autumn, from September 

 to December, in this country most frequently in October; 

 the spring varieties from January to March, most usually in 

 February. 



The seed is drilled in rows from 7 to 10 inches apart, the 

 amount used varying from ij to 3 bushels per acre. 



Yield. — The average yield in this country is about 28J 

 bushels, but 60 bushels or more per acre are sometimes obtained; 

 a yield of 40 bushels is usually considered a good crop. 



Composition. — The composition of the wheat grain varies 

 much with the climate, soil, manuring, and variety of the plant. 

 The ' soluble carbohydrates,' mainly starch, average about 66| 

 per cent. ; the albuminoids, iij; the 'fibre,' 3; the fat, ij; the 

 water-content usually about 14 per cent. 



The albuminoids in some grains are as low as 8 per cent., 

 while in others they may be as high as 24 per cent. ; the flinty 

 grains are usually richer in this class of substances than the 

 mealy ones of the same variety of wheat. 



Ez. 267. — Examine the spikelets of a ripe ear of common wheat, and note 

 the number of flowers which have produced well-formed grains, and the 

 number of abortive flowers. 



Ex. 268. — If possible obtain specimens of the various species, races, and 

 varieties of wheat. Note the shape and colour of the caryopsis, the presence 

 or absence of an awn and keel on the empty and flowering glumes, and the 

 stifihess, solidity, or hollowness of the intemodes of the straw of each. 



Ez. 269. — The student should also make a point of examining the general 

 form of the ears of different common named-varieties of wheat. Measure 

 how many spikelets are arranged on 2 inches of rachis in each ear. Note 

 also the colour of the chaff and grain in each. 



