LETTI^R OF TRANSMITTAL. 



U. S. Department of Agriculture, 



Bureau of Plant Industry, 



Office of the Chief, 

 Washington, D. C, August I4, 1911. 



Sir: I have the honor to transmit herewith and to recommend 

 for pubUcation as Bulletm No. 218 of the series of this Bureau a 

 paper by C. P. Hartley, Ernest B. Brown, C. H. Kyle, and L. L. 

 Zook, entitled "Crossbreeding Corn." This article presents one 

 feature of the work of the Office of Corn Investigations on the project 

 of finding and developing higher yielding strains of corn for different 

 geographical sections of the United States. The success that is 

 being attained along this line is due to the utilization of the effects 

 of acclimatization, adaptation, crossbreeding, and selection. 



The results of field tests in four States are given in detail. In 

 this report the results are assembled in a manner to show the rela- 

 tive productiveness of first -generation crosses and their parent 

 varieties. While these results include a part of the data that are 

 being assembled to show the effects on corn of acclimatization and 

 adaptation, only such mention is here made of these influences as 

 will prevent their effects being attributed to crossbreeding. 



These investigations assist m determining what varieties and what 

 combinations of varieties can be most profitably grown in different 

 localities. They also assist in revealing the qualities of seed corn 

 that influence its productivity. Knowledge of this nature is espe- 

 cially needed at this time to assist in establishmg successful methods 

 of corn improvement embracing the good effects of selecting fine- 

 appearing ears and of crossbreeding, without leading practical corn 

 growers mto the belief that prize-winnmg eare are necessarily profit- 

 able seed ears or that a well-selected and well-adapted variety is 

 usually less productive than its first-generation cross. 



The results presented here are the first results of a series of tests 

 being conducted with many varieties under various environments. 

 More work more accurately conducted is necessary before general 

 conclusions of a positive nature are warranted, but the urgent need 

 of facts concerning our most widely grown and most valuable crop 

 makes it advisable to publish in detail these results, which are at 

 once of both local and general value. 



Respectfully, B. T. Galloway, 



Chief of Bureau. 



Hon. James Wilson, 



Secretary of Agriculture, 



21s 3 



