80 CROSSBREEDING CORN. 



These results show that some varieties combine or "nick" well' 

 when crossed, forming crosses that arc superior in yielding power to 

 either parent, while other varieties do not combine well and the 

 crosses are either less productive than the better parent or inferior 

 to both parents. The factors that determine what the productive- 

 ness of the cross will be are not known, and apparently no external 

 characters are discernible by which we can judge of their presence 

 or absence. It is important, therefore, that crosses of varieties should 

 be tried experimentally to ascertain their productiveness before 

 growing them commercially or before making a general agricultural 

 application of tliis method of corn breeding. 



It is worthy of note that the crosses which produced best under the 

 somewhat adveree conditions at Chico are not from the same combi- 

 nations as those which produced best under conditions of normal 

 rainfall in Marvland. 



Table VII shows a comparison between an acchmated, well-adapted 

 variety, the crosses of this with two varieties of later introduction, 

 and these two varieties themselves. 



In each of tliese comparisons the cross is intermediate in yield per 

 stalk between the two varieties crossed. In other words, nothing 

 was gained in yield by crossing an adapted, well-acclimated variety 

 with a variety of later introduction, even though this variety is also a 

 good yielder. 



TESTS IN TEXAS. 



WORK OF 1909. 



Seed of a number of pure-bred varieties of corn was obtained early 

 in 1909 for use in crossbreeding experiments in Texas A list of 

 these varieties and a brief description is given in Table VIII. The 

 varieties were planted at Waco, Tex., early in March, 1909, one row 

 of each of the other varieties alternating with two rows of Chisholm 

 (the variety chosen to be the male parent). Tassels were removed 

 from the stalks of all varieties except the Chisholm before any pollen 

 had been shed. The crosses made in this manner, each lmA"ing the 

 same male parent but a different female parent, were planted in 1910 

 at Sherman, at Waco, and at Corsicana. 



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