314 



chemical composition; maize is modified as to its size; rye varies 

 very little with change of conditions, except as to the effect upon the 

 htraw ; but, as we have seen, wheat changes both its external appear- 

 ance and its chemical constituents. 



With regard to maize, the high ripening temperature of the South- 

 ern States appears to diminish the size of the kernel and prevent a 

 large formation of starch. But the variations in size peculiar to the 

 varieties are much smaller than variations that are due to the climate 

 and soil, thus Dent varieties of corn from Tennessee and Indiana have 

 been found weighing, respectively, 64.1 and 13.9 grams per 100 ker- 

 nels, or a ratio of 5 to 1 in the weights of the kernels. Hence a 

 comparison of the yield per acre by the weights of the crops would 

 differ very much from a comparison by volumes in bushels. The per- 

 centage of albuminoids varies very much less in the large and small 

 kernels of maize. 



As to oats, the climatic surroundings cause a ver}" large variation 

 in their physical appearance. The extreme weights per bushel are 

 48.8 and 24.7 pounds; the extreme ratios in the weight of the kernel, 

 with reference to the weight of the kernel plus the hull, are 79 and 55 

 per cent. The average composition all over the country as to the 

 percentage of albuminoids is between 12 and 10 per cent, except in a 

 few extreme cases of 9 and 19 per cents, which are as liable to occur 

 in one locality as in another. 



Barley is not as variable in composition and aj)pearance as wheat 

 and oats; the extreme weights per bushel are 00.2 and 50.4 pounds, 

 and the extreme weights of 100 kernels are 4.900 and 2.630 grams; 

 the extreme percentages of albuminoids are 14.88 and 8.75. For 

 malting purposes the large quantity of albuminoid is not desirable, 

 while starch is desirable. 



WHEAT— GENERAL RELATIONS TO CLIMATE AND SOIL. 



In his tenth census report Professor Brewer says : 



While the cultivation of wheat in a commercial sense is determined 

 by a complicated set of conditions, in an agricultural sense the matter 

 is very much simpler. The yield and quality of the crop practically 

 depends upon but five conditions — the climate, the soil, the variety 

 cultivated, the method of cultivation, and the liability to destruction 

 by insects. Even under poor cultivation and exemption from insect 

 depredations, if the other three conditions are favorable good crops 

 of wheat of good quality may be very often grown, and in a good 

 climate and with a good variety of wheat an excellent quality may be 

 grown even where the soil is comparatively poor. The yield may 

 be small, but the grain itself will be good. 



As regards soils, we nvAj say in a general way that light clays and 

 heavy loams are the best for wheat. On the one hand, very heavy 



