105 



Field Test. — Out of 125 bushels of selected seed corn, I reselected 

 enough to plant a thirty-acre field — from which in turn seed for the fol- 

 lowing year was to be selected, and the germinating test for each ear had 

 to be high. Out of this reselected seed a sufficient amount was put through 

 the specific gravity test until there were enough light kernels to plant a 

 row of 80 rods. The test corresponded with test No. 3, that is, 90 per cent, 

 of the kernels were heavy ; all germinated. These light seed were planted 

 in a row alongside of one of heavy; the rows were "checked" and ran 

 east and west, the light row being on the south. Now as our prevailing 

 winds are from the southwest, one can readily see how there might thus be 

 a slight difference : the row of heavy kernels might be fertilized by pollen 

 from the light kernels rather than the reverse. 



There was no perceptible difference in the appearance of these two 

 rows, but when a count of stalks was made in August, the heavy row 

 showed an excess of 129. When ripe, the ears from each row were husked 

 and weighed, and there was found to be a difference of 20 pounds in favor 

 of the heavy row — equivalent to nearly three bushels to the acre. 



My conclusions from these experiments are as follows : 



1. To test seed corn by the germinating test is time-consuming and 

 expensive, and requires great care. 



2. Choosing five kernels to represent 600 to 1,000 others from an ear 

 does not prove to be an infallible method. (Test 4.) 



3. To test by specific gravity is simple, rapid, and inexpensive. 



4. The specific gravity test enables one to eliminate the weak kernels 

 in a simple and practical manner. 



5. The crucial test, the field experiment, shows that the light grains 

 should be discarded. 



