580 Reading-Course for Farmers. 



In a tuber of this shape the center of the potato at any point is only 

 about one inch from the exterior. 



(2) When the ideal character and size have been determined, examine 

 a large number of tubers and pick out a thousand or more having this 

 size, shape and general character. This is work that can be done in the 

 late fall and winter when there is no rush of other farm work, and time 

 should be taken to secure a considerable number of these tubers of the 

 same character. These are to be used as the seed for planting the 

 selection plot and the number selected should correspond to the size of 

 the plot which it is desired to plant, four hills being planted with each 

 tuber. There should certainly not be less than one thousand and a 

 much larger number is more desirable. The prospective breeder 

 should remember that success in breeding work depends upon selecting 

 the one individual that gives the ver}^ highest 3ield possible under the 

 conditions, and the larger the number of individuals examined the 

 more likely is he to discover the one producing the maximum yield 

 which will give a valuable new strain. There is no loss in growing this 

 selection plot aside from the greater amount of time required for the 

 digging, so that one should grow a considerable number of plants. 



(3) The planting should be arranged in such a way as to secure a test 

 of the productivity of each tuber. To do this the following method may 

 be recommended. Cut each tuber into four uniform sized pieces, mak- 

 ing each cut longitudinally so that each piece will contain an equal pro- 

 portion of the basal end and the apical end of the tuber. Plant four 

 hills with each tuber, one piece in the hill. These should be planted con- 

 secutively in each row beginning at one end, so that starting at that 

 end the first four hills will be from one tuber, the second four from another 

 and so on throughout the length of the row. The object in planting this 

 way is that four hills can be dug together and the total product weighed 

 to obtain a measure of the productivity of the seed tuber planted (Fig. 2). 

 Probably the best way to plant these is to drop the selected tubers one 

 to each four hills and then go over the row and cut each tuber and 

 plant its quota of four hills. The hills in the row should be planted 

 somewhat farther apart than in ordinary' planting, probably 20 to 24 

 inches. If this is not done a somewhat greater distance than ordinar}^ 

 should be left between each two four-hill tuber-units. The writer would 

 advise that one hill be left unplanted between each two four-hillunits. It 

 would doubtless be convenient and desirable to have the plants in rows 

 both ways to facilitate digging. For this selection-plot of potatoes, 

 choose a field of moderately good fertility and as uniform throughout 

 in soil as it is possible to obtain. 



