i68 Bulletin 251. 



select about fifty of the best units. These fifty units should naturally be 

 from those marked as having good healthy vines in the first examination, 

 before digging, unless all of the vines at that time were in fairly good 

 condition. In making these final selections if some hills in a tuber-unit 

 are missing the comparative yield can be easily calculated. If one hill is 

 missing a comparative yield for four hills in obtained by increasing the 

 weight from the three hills by one third, li two hills are missing a 

 comparative yield for four hills would be double that obtained from the 

 two hills. If more than two hills are missing discard the unit entirely. 



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 twelve pound manilla paper bag used by 

 grocers. Number each tuber-unit consecutively and place this number 

 on the 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 and the tubers 

 mixed. The tubers from the best discarded tuber-units should be re- 

 tained 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. 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. 



Selecting seed for the second years planting. 



Some time during the winter or at any convenient period before 

 planting time carefully 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 

 remaining tubers. 



Second yca^-'s planting. — In the further handling of the selections 

 made the first year the planting the second year must be arranged in 

 order to test the productive power of each of the fifty select tuber-units. 

 Plant each tulier-unit in a row by itself 1)y the same method used in 

 planting the first year's crop (see p. TfS5). 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 



