Appendix E 465 



6. Why should corn breeding plots be isolated? What is a 

 safe distance? 



7. Why should timothy breeding plots be isolated ? What is a 

 safe distance? 



8. Is it necessary to isolate breeding plots of the small cereals? 



9. In selection work, what three rules should the breeder 

 follow who understands the principles of pure-line breeding? 



Scheme for Potato Breeding Plots 1 



First Year. Choose 500 good tubers. Plant them in a 

 breeding plot by the tuber-unit method. Rows should be 3 

 feet apart, hills 1 feet apart in the rows. At harvest time 

 choose the best 50 units. Save the best 10 from each of these 

 units for planting a breeding plot the next year. 



Second Year. Plant the selected tubers in a breeding plot 

 as in the first year. At harvest time discard all poor units. 

 Select the best 50 units. Save 10 of the best tubers from each 

 of these units for planting the third year's breeding plot. Use 

 the rest for planting a field crop the next year. 



Third Year. Use these 500 tubers to plant a breeding plot. 

 Plant your field crop with the remaining choice tubers. How 



1 For details of the following schemes read Cornell University Exp. 

 Sta. Bull. 251, "Plant Breeding for Farmers," 1908 ; also Bull. 313, "The 

 Production and Improvement of New Varieties of Timothy." 



For cotton breeding, see Webber, H. J., "Improvement of Cotton by 

 Seed Selection," U. S. Department of Agr. Yearbook, 1902, pp. 365- 

 386. 



16.5 ft. = 1 rod ; 160.0 sq. rd. = 1 acre. 



Plant : Corn, 8-12 qt. per acre ; Oats, 2-3 bu. per acre ; Wheat, 

 2-3 bu. per acre ; Barley, 2-3 bu. per acre ; Potatoes, 12-15 bu. per acre; 

 Timothy, 6-8 qt. or 16 Ib. per acre. 



Standard weights: Corn, 1 bu. = 70 Ib. shelled, or 56 Ib. on cob; 

 Oats, 1 bu. = 32 Ib. ; Wheat, 1 bu. = 60 Ib. ; Barley, 1 bu. = 48 Ib. ; 

 Potatoes, 1 bu. = 60 Ib. ; Timothy, 1 bu. = 45 Ib. 



Average yield per acre in United States for 1902: Corn, 20.2 bu. ; Wheat, 

 15.9 bu. ; Oats, 37.4 bu. ; Barley, 50.4 bu. ; Potatoes, 113.4 bu. 

 2n 



