Methods of Brkedixg axd Improving the Potato Crop. 579 



ing potatoes extensively to test varieties sufficiently to determine which 

 is the variety best suited to the local conditions concerned. This 

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

 in a region has usually shown the general superiority of a comparatively 

 few varieties and a test can thus be limited to these varieties 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 atten- 

 tion that it does not pay to start with an inferior 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 con- 

 ditions, he is in position to start the selection without a further 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 

 ordinar}^ way are very poorly adapted to begin the work of selection. 

 It is of primary importance that the first selections be of the very 

 highest type obtainable, 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: 



(i) Examine a large number 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, which is oblong or some- 

 what cylindrical in shape and oblong in cross section, is considered most 

 desirable (Fig. i). 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 to be cut when sensed, as 

 a single tuber is about the right size to serve to an individual. Again 

 this sized tuber is well fitted for cooking and it is small enough so that the 

 interior will cook nearly as quickly as the exterior. Probably the most 

 desirable shape is when the tuber has a major axis or length of three 

 and one-half to four inches, with a width of possibly three to three and 

 one-fourth inches, and a thickness of two to two and one-fourth inches. 



