SEED INSPECTION 101 



Variety Variation Studies With Seed Corn 



Conducted in Cooperation with the Department of Agronomy, 

 William G. Colby, Research Professor 



In the spring of 1939 seventy-two samples of corn, collected from different 

 seed sources, were planted in single row plots and grown to maturity. Almost all 

 of the important open-pollinated corn varieties grown in Massachusetts were 

 represented in the collection. In a few instances only one sample of a variety 

 was taken, but in most cases the same variety was collected from a number of 

 different sources. The object of the study was to determine the range of varia- 

 tion between lots of seed sold under the same varietal name but originating from 

 different seed sources. 



Observations were made on the general plant and ear characteristics, the tas- 

 seling date and the ripening date of each sample. A fair degree of uniformity 

 was found between different lots of the same variety with respect to such varietal 

 characteristics as ear shape and kernel shape and color, but wide variations were 

 found in the height of plant (see illustration on page 104) and the number of 

 days required for ripening. In one instance seed of a variety from one source 

 matured three full weeks ahead of seed sold as the same variety from another 

 source. In several cases there were differences of ten days in maturity be: wren 

 different seed sources. 



The results of this study clearly indicate the unreliability of variety names in 

 corn varieties. It should be emphasized, however, thai this condition is not 

 the fault of the seedsmen but is rather an inevitable result associated with the 

 seed production of an open-pollinated species. The relative ease by which the 

 characteristics of an open-pollinated variety may be changed by different growers 

 consistently selecting for different strain types, or by carrying on selection under 

 different climatic environments, has resulted in the isolation of main strains 

 within all important varieties. The corn grower then should bear these facts 

 in mind when buying seed of an open-pollinated corn variety. Unless he knows 

 just how a particular dealer's strain of a variety will perform under his local 

 growing conditions, he is likely to be disappointed with the results from (he use 

 of commercial seed. 



This situation will be greatly improved with the increased use of hybrid corn. 

 The pollination is controlled in this case and consistent. Uniform performance 

 can be expected from any given hybrid provided it comes from a certified seed 

 source. 



In the following table laboratory numbers to which the letter "F" has been 

 added indicate that the samples were taken from seedsmens' stock by a State 

 Inspector and were tested for viability in the Seed Laboratory. The source of 

 the seed and results of laboratory tests are given on Pages 15 to 23. 



