106 AGRICULTURE 



hill rows is kept for seed for the general crop for the fol- 

 lowing year. By thus keeping a breeding plat for seed, po- 

 tatoes can be greatly improved, and the yield much in- 

 creased. 



The tuber-unit method can be rendered even more ef- 

 fective by making the first selection from the field instead 

 of the potato bin. This is done by going into the field 

 before the vines begin to die and marking a number of 

 the most vigorous and desirable plants. These are har- 

 vested separately before wholly mature, and seed taken 

 from the best hills. 



The practise of planting for seed the small and unmar- 

 ketable potato culls can not be too strongly condemned. It 

 lessens the yield, lowers the quality of the crop and causes 

 the variety to deteriorate. 



Cutting seed potatoes. Whether it pays better to 

 cut potatoes for seed or plant the whole tuber has been 

 much discussed. It is believed by many potato growers 

 that under average conditions the yield will be greater when 

 quarters are planted than when pieces with single eyes are 

 used, and that halves will produce more than quarters. It 

 is not sure that whole tubers will produce a larger yield 

 than halves. The weight of experience seems to favor 

 planting halves. 



Immature seed. For vitality, high yield and good 

 market qualities, potatoes intended for seed should be har- 

 vested before entirely ripe (by hill selection) that is, be- 

 fore the vines have died. Many experiments have shown 

 that immature seed will produce a considerably higher yield 

 than seed allowed to ripen before digging. 



Home-grown seed not always best. Contrary to the 

 rule with most farm crops, seed brought from another 

 region often produces a better crop of potatoes than h.ome- 



