CORN CROSSES AT CHICO, CAL., 1910. 27 



COMPARISON OF CROSSES WITH PARENT VARIETIES. 



It has been claimed, though not universally accepted, that first- 

 generation corn crosses are superior in pro(hicing power to the 

 varieties crossed. The (hita herein submitted seem to bear out such 

 a conclusion when the majority of cases and the average of all are 

 considered. 



Of the 18 crosses included in this test, only 2 do not exceed in yield 

 the average of the two varieties crossed. The average yield per 

 stalk of the 10 plantings of Selection 119 is 0.280 pound; for the 18 

 varieties used as female parents, 0.284 pound; and for the crosses, 

 0.320 pound; an increase of 0.038 pound per stalk in favor of the 

 average of the crosses. 



There is no special advantage in growing first-generation crosses 

 unless such crosses can be depended upon to yield consistently and 

 constantly more than either of the varieties used in making the 

 cross. This gain must be sufficiently large to insure compensation 

 for the rather careful work necessary in making the cross and in 

 keeping pure two varieties of corn for tliis purpose. 



Of the 18 crosses in this test, 9 exceed either parent in the yield 

 per stalk, and 9 are e([ualed or exceeded by one or the other of the 

 parents. The difference in the yields of the better parent and of the 

 cross ranges in amount from 4 to 20 per cent in the 9 comparisons in 

 which the crosses exceed, and from zero to 17 per cent in the 9 in 

 which the better parent exceeds the cross. 



Not only are there the same number of comparisons in which the 

 cross exceeds and fails to exceed the better parent, but the average 

 yield per stalk of the crosses and that of the better parents is the same, 

 being 0.320 pound in each case. 



These data do not show that first-generation crosses can, in the 

 greater number of cases, be depended upon to produce more than the 

 better of the two varieties crossed. 



Two additional crosses were grown in the test at Chico. The male 

 parent used was Selection 160, a large yellow flint. This corn has 

 been grown in California for 12 years or more and at Chico for 5 

 years. It seems to be well acclimated and has proved to be the best 

 yielder of a number of varieties grown at Chico in the last 3 years. 



The two varieties used as female parents were Ohio Leaming and 

 Silvermine. Next to Selection 160 these have been the liighest 

 yielding of the varieties tested at Chico. 



The crosses were made by hand-pollinating ears of these two 

 varieties with pollen from Selection 160 in the varietal test rows at 

 Chico in 1909. Several ears in each variety were also poUinated 

 with pollen from different stalks of the same variety. In this way 

 seed of the cross and that of the female parent used in the experiment 



218 



