Potafo Breeding 63 



Selection of foundation stock of potatoes. — Probably no crop 

 generally grown is more influenced by environment than the potato. 

 The experience of growers indicates that a variety found to be the 

 best suited to local conditions on one farm may not prove to be the 

 variety best suited to the conditions existing on an adjoining farm. 

 It thus becomes desirable for any farmer who is growing potatoes 

 extensively to test varieties sufficiently to determine which is the 

 variety best suited to the local conditions cfincerned. This ordi- 

 narily does not require an extensive test as the experience of growers 

 in a region has usually shown the general superiority of a com- 

 paratively few varieties, and a test can thus be limited to these varie- 

 ties which in general are known to be the best. The writer would 

 not urge this test of varieties, if it were not very important to begin 

 any breeding work with the best variety available. Breeding work 

 requires so much attention that it does not pay to start with an in- 

 ferior variety. The first effort of any one contemplating breeding 

 with potatoes is thus to determine the best foundation stock to use 

 for the selection work. If the grower has had extensive experience 

 in growing potatoes and has determined that a certain variety 

 gives the best results under his conditions, he is in a position to start 

 the selection without a fm-ther test of varieties. 



Growing potatoes for selection. — The influence of the number of 

 eyes and size of piece planted as seed has so much to do with the 

 yield of the hill that fields planted in the ordinary way are very 

 poorly adapted to begin the work of selection. It is of primary im- 

 portance that the first selections be of the very highest type obtain- 

 able, as it is a common experience that the first selection is the most 

 important. Too much attention cannot be given therefore to the 

 first selection. The writer would thus urge the following method 

 as one of the most satisfactory to be pursued : 



(1) Examine a large niunber of tubers of the variety selected as 

 the foundation stock and decide on the most desirable shape and 

 type of tuber. In general a moderately large tuber, wliich is oblong 

 or somewhat cyUndrical in shape and oblong in cross section, is 

 considered most desirable. A spherical tuber if sufficiently large 

 to be desirable is so thick that in cooking the outside is likely to 

 become overdone before the interior is properly cooked. A tuber 

 with shallow eyes, netted surface and white color is also usually 

 preferred. Probably the best-sized potato for general use is one 

 weighing seven to eight ounces. A potato of this size does not have 



