388 GARDEN FARMING 



for the breeder. Just now the idea of securing sorts resistant to 

 disease is uppermost in the mind of the potato grower. Sorts, both 

 old and new, home-grown and foreign, are being subjected to the 

 tests for disease resistance, which is the all-important factor. 



The work of plant breeding has so advanced during the last dec- 

 ade that the task of securing plants with definite desirable quali- 

 ties is much more certain at the present time than ever before. In 

 fact, plant breeding has acquired somewhat the same certainty as 

 animal breeding. The plant breeder, like the stock breeder, should 

 have a well-defined ideal in mind before undertaking his task. The 

 next step is an inventory of the existing sorts for the purpose of 

 determining the degree to which they meet the new ideal and 

 their prepotency and vigor when used as breeding stock. Among 

 the potatoes none seem to have greater ability to adapt them- 

 selves to new conditions or to develop desired characteristics and 

 qualities than the Early Rose and its numerous progeny. 



New varieties of potatoes may arise in three ways : (i) as a 

 result of seed reproduction through chance seedlings or through 

 direct cross-fertilization ; (2) through bud variation or sporting, not 

 unknown but not usual ; (3) by selection and line breeding, a very 

 important means of increasing the commercial value of a variety 

 without resorting to the intervention of the seed. By selecting 

 tubers of a desired type from the most productive hills the yield 

 and general character of the variety can be maintained at a high 

 standard. If the work be still more restricted, and the start made 

 from a single tuber selected from the most productive hill, and a 

 line of selection followed in which the seed used is chosen each 

 year only from the most ideal hills in the progeny, a strain of 

 superlative merit will be built up. For the commercial grower this 

 method is thoroughly practicable and will be found to repay well 

 the time and effort expended. In fact, the advantages from such 

 care in handling potatoes are quite as marked as in the case of corn. 



Seed reproduction. The development of new sorts of potatoes 

 by means of seed production is fascinating work. There is a suf- 

 ficient element of chance connected with it to lend it the charm 

 which makes it worth while. Chance seedlings are, however, less 

 interesting than those which are the result of close pollination or 

 of a definite cross. In chance seedlings none of the factors are 



