42 



BREEDING CROP PLANTS 



tobacco crosses and their parents. All crosses do not prove 

 equally vigorous and a few give no increase as compared with the 

 parental average. In general, however, the crosses show in- 

 creased yields. As the tobacco flower produces many seeds, 

 Houser (1912) believes the extra cost of production would not 

 be prohibitive. Before this plan can be adopted commercially, 

 extensive studies are needed to determine the value of particular 

 Fi tobacco crosses. 



TABLE IV. RELATION OF YIELD PER ACRE BETWEEN FIRST GENERATION 

 HYBRID TOBACCO AND THE PARENT PLANTS 



The vigor of FI tomato crosses has received some study. The 

 first extensive test was made by Wellington (1912) at the Geneva 

 (New York) Station. A 3-year test was made under field con- 

 ditions of a cross between Dwarf Aristocrat, a dwarf tomato, 

 and Livingston Stone. Yields of the parents, the FI, and the F% 

 generations are given. 



We are not so much interested at the present time in the com- 

 mercial value of such crosses as in the development of the princi- 

 ple involved. Wellington believes the above cross of sufficient 

 value to more than pay for the cost of producing crossed seed. 



Similar results were obtained at the Connecticut Station in a 

 cross between Stone and Dwarf Champion tomatoes. The 



