103 



Testing Seed Corn by Specific Gravity. 



By Herbert A. Dunn. 



The corn of our native Indians as found by the first settlers in this 

 country was small in size and of an inferior quality. The white man real- 

 ized the possibilities of this new corn and at once began to select and im- 

 prove it. This has been a slow process, and more improvement has prob- 

 ably been made in the last generation than in all the years preceding. 

 The average yield in the United States for the decade ending in 1875, ac- 

 cording to J. W. T. Duvel, assistant in the seed laboratory, Bureau of 

 Plant Industry, Washington, was 2G.07 bushels per acre, and the yield for 

 the decade ending in 1905 was 25.2 bushels ; the largest yield in any one 

 year was in 1906, 30.3 bushels per acre. 



During the year 1907 practically one hundred million acres were 

 planted in the United States, requiring sixteen and a half million bushels 

 of seed. Observation has shown that 20% of this seed does not germinate, 

 the chief reason for this being carelessness in selecting and caring for the 

 seed corn. 



The yield will depend on the vitality of the seed and on contingency 

 of the weather and soil and cultivation. In years past corn has been 

 planted with little thought of the type of grain and germinating power; 

 often only a random test was made by the aid of a pocket knife. Ex- 

 perienced farmers say that this is a fairly good test but experiment sta- 

 tions rely on and advocate the germinating test. Both of these tests re- 

 quire much time. 



Since the yield is largely dependent on the quality of the seed corn, 

 a comparatively simple and efficient seed test is very desirable. 



One day I accidentally dropped some kernels in a basin of water. I 

 noticed that the majority of the kernels lay flat on the bottom, while 

 some stood on end, and on examining the latter they were found to be 

 shriveled on the germ end, or had blisters. This gave me an idea of using 

 a specific gravity test, for it must be evident that by increasing the density 

 of the solution the light kernels would rise to the top. The question arose : 

 What should be added to the water that is both harmless and cheap? I 



