Potato Breeding 67 



The product of the tuber-units selected should then be placed in 

 paper bags, the product of one tuber-unit only being placed in a bag. 

 A good bag for the purpose is the 12 or 16 pound manila paper bag 

 used by grocers. The 12-pound paper bags of good quality should 

 cost only about 40 cents per hundred. If the 12-pound paper bag 

 is too small, use a 16-pound bag. In your notebook record under 

 the number of each tuber-unit, the number of large, medium-sized, 

 and small tubers and the total weight of the product. The bags 

 containing the seed should then be placed in suitable storage where 

 they will not be torn or the tubers mixed. The tubers from the 

 best discarded tuber-units should be retained to plant the general 

 crop the next year. 



If at digging time the grower is crowded with work and wishes 

 to save time, the two or three hundred tuber-units retained after the 

 first gross selection (see paragraph 2 above) could be placed in paper 

 bags and the more careful examination and weighing of the product 

 delayed until some convenient time during the winter when the final 

 selection could be made. 



Selecting seed for the second year's planting. — Some time during 

 the winter or at any convenient period before planting time care- 

 fully examine the product of each select tuber-unit and pick out the 

 ten best tubers of each as judged by the ideal standard of a good tuber 

 which has been taken as the type of the selection. The ten best of 

 each retain in the numbered sacks for planting and discard the re- 

 maining tubers. 



Second year's planting. — In the further handling of the selec- 

 tions made the first year the planting the second year must be ar- 

 ranged in order to test the productive power of each of the fifty 

 select tuber-units. Plant each tuber-unit in a row by itself by the 

 same method used in planting the first year's crop (see p. 64). That 

 is, plant four hills with each tuber, cutting the tuber longitudinally 

 into four equal-sized quarters, making each cut from base to apex 

 of the tuber. As ten select tubers were retained from each tuber- 

 unit this will make forty hills per row, and if fifty tuber-units were 

 selected, there will be 500 tubers to plant, which will make a total 

 of 2000 hills in the breeding-plot. The land used for this breeding- 

 plot should be carefully chosen for uniformity, as variations in the 

 land will modify the comparative yield and are likely to render the 

 results untrustworthy. Number each row of forty hills with the 

 number given the tuber-unit of the preceding year. It is desirable 



