GERMINATION TEST 



113 



TABLE NO. 25 



SHOWING DECREASE IN PER CENT STAND AND YIELD WITH DECREASE 

 OF VITALITY AS MEASURED BY THE GERMINATION TEST* 



S=Strong W=Weak D=Dead 



From the seed ears showing all six strong sprouts, the average 

 yield was 75.1 bushels per acre. From the seed ears with one kernel 

 out of the six kernels tested, failing to sprout in the test, the yield in 

 the field was reduced 9.7 bushels per acre. Seed ears from which two 

 of the six kernels tested failed to sprout yielded 16.5 bushels per acre 

 less than the strong ears. Where three out of the six kernels failed to 

 sprout the average yield from the seed ears shows a decrease of 25 

 bushels per acre. With four of the six kernels failing to sprout the 

 yield from these seed ears was reduced 33 bushels per acre. From 

 seed ears where five of the kernels failed to sprout in the test the 

 average yield was reduced 35.7 bushels per acre, and where all six 

 kernels failed to grow a decrease in yield of 40.3 bushels per acre was 

 found. The yield recorded from ears which failed to germinate when 

 tested is explained by the presence of kernels scattered through the 

 ears which have escaped injury. However one would not wish to 

 plant such ears which so greatly reduce the yield. 



Covering a period of seven years the results of the farmer's var- 

 iety tests in Iowa in twenty-eight counties and covering 55 tests show 

 the condition of the seed corn being planted each year, and serve 

 further to demonstrate the relation of the germination test to the yield 

 of corn in the field. In these tests the seed corn used was taken from 

 the planter boxes of farmers right in their fields while planting. The 

 seed was planted by hand, three kernels per hill, with exactly the 

 same preparation of seed bed, uniform soil, and same cultivation. 

 Each sample was planted in difiEerent parts of the field in order and 

 careful records were kept of stand and yield. Furthermore, several 

 germination tests were made of each sample and the average test 

 recorded. The following table gives a summary of the data : 



•Iowa Bulletin No. 135 



