CORN CROSSES AT CHICO, CAL., 1010. 29 



highest yiekhng varieties. This view is supported by the results of a 

 test of the same varieties and crosses in ISIarylanrl and also by the 

 results obtained from the two crosses with Selection 160. 



While this influence apparently exists, it is not sufficiently constant 

 to be relied upon, as is shown by comparing the crosses Silvermine 

 X Selection 119 and Ohio Learning X Selection 119. The female 

 parents of these crosses rank second and third in yield among the 

 original varieties; the crosses are surpassed in productiveness by the 

 crosses Sturges Hybrid Flint X Selection 119 and Cross 100 X 

 Selection 119, the female parents of which rank low in yield. 



The four best producers of the original varieties are Golden Eagle, 

 Silvermine, Ohio Leaming, and Selection 77. The crosses of these 

 four varieties with Selection 119 are distributed in the following 

 manner as regards the degree of benefit from crossing: One case in 

 which the cross shows a decided increase over the better parent, 

 one in which the cross is intermediate between the two parents, and 

 two in which the cross about equals the poorer parent. 



The five poorest producing varieties are Cross 100, Fraley Yellow 

 Dent, Hickoiy King, Whitecap, and Sturges Hybrid Flint. The 

 crosses of these five varieties with Selection 119 are distributed as 

 follows as regards benefit from crossing : Three better than the better 

 parent, and two intermediate between the two parents. 



The crosses with Selection 119 that show the greatest gain in yield 

 over the better of their two parents are those of Red Blaze, Golden 

 Eagle, Selection 137, and Cross 120. If yields of the original varieties 

 and of the crosses are both considered, the female parents of these 

 high-yielding crosses may be classed as one good and three interme- 

 diate in respect to yield. 



From the examples set forth in the preceding paragraphs it would 

 seem that no constant relation exists between the productivity of 

 varieties and the increase or decrease in yield of their crosses as 

 compared with the parent varieties. The lack of constancy in this 

 relation may be seen in the following crosses: Ohio Leaming X 

 Selection 119 produces less than either parent, although both are 

 high-yielding varieties that have been pure bred for many years; 

 the cross of Red Blaze (a high-yielding and well-selected variety) X 

 Selection 119 gives an increase in yield of 20 per cent over the better 

 parent; the cross of Cross 100, the lowest yielding variety in the test, 

 vnth Selection 119 gives an increase in jaeld of 11 per cent over the 

 better parent and practically equals in yield that of Ohio Leaming X 

 Selection 119 (ranking eighth in yield among the crosses); while 

 Fraley Yellow Dent, the next lowest yielding variety, crossed with 

 Selection 119 is the lowest yielding cross in the test and is exceeded 

 by all the varieties except Cross 100 and Fraley Yellow Dent. 



218 



