THE OAT GRAIN 



151 



two flowers. They are usually self-fertilized, though natural 

 crossing occasionally occurs. Varieties vary in respect to the 

 development of the second flower into a grain. In some cases 

 there is a strong tendency for only the lower grain to develop, while, 

 on the other hand, there are varieties that show a strong tendency 

 to develop both grains equally. A few varieties develop three grains 

 normally. Between these are all intermediate stages. In general, 

 the second grain is about two-thirds the size of the lower grain. 



The Oat Grain. Except in the case of " hulless " oats the oat 

 kernel is always tightly enclosed in the flowering glume, called the 

 hull. The kernel and hull combined are called a " grain " (Fig. 55) . 



The proportion of kernel in good oats will usually average about 

 70 per cent and hull 30 per cent. Oats are quite variable in this re- . 

 spect, however, the usual range being from 25 to 35 per cent hull, 

 with occasional extreme variations as low as 20 per cent and as high 

 as 45 per cent. A good example may be cited from the Ohio Experi- 

 ment Station, where 36 varieties showed a variation in one season 

 of from 23.9 per cent to 36.7 per cent hull. 3 As these data illustrate 

 several common variations in oat varieties, a list of 10 selected 

 varieties with accompanying data is given : 



Characteristics of Ten Common Varieties of Oats 



3 Ohio Bulletin 257, 173. 



