Plant-Breedixg for Farmers. 



163 



produce fewer and fewer seeds. This would naturally be especially true 

 when as, in the potato, the part for which the plant is grown is not the 

 fruit. The difficulty of obtaining seeds from our ordinary types and, 

 furthermore, the cost and expense of growing and testing seedlings, would 

 preclude this type of potato-breeding from being recommended as desir- 

 able for farmers generally to undertake. Fortunately, however, we 

 have in the potato an illustration of a plant that can apparently be 

 greatly improved by tuber or bud selection. Where a single whole 

 tuber is planted in a hill the yield of the hill becomes a measure of the 

 productivity of the bud which formed the seed tuber planted. Ex- 

 periments which have been conducted by several investigators, have 

 demonstrated that hills differ greatly in their productivity and that this 

 tendency is one which is in considerable degree transmitted to the hill or 

 tuber progeny. The most reliable results of this kind of which the writer 

 has knowledge, are those which have been obtained by C. W. Wade of the 

 Ohio Experiment Station, at Wooster, Ohio.^ 



In these experiments which were begun in 1903, ten high-yielding 

 hills and twenty low-yielding hills were selected and the seed preserved 

 separately. In 1904. ten hills each were planted from seed of the ten 

 heavy hills and five hills each from seed of the light-yielding hills, making 

 100 hills of each group. To compare with these as a check, 100 hills 

 were planted from seed which had been selected without reference to indi- 

 vidual hills. 



In 1905, 100 hills were again planted with seed from high-yielding 

 hills and 100 hills from low-yielding hills, the seed being selected respec- 

 tively from the high-yielding and low-yielding hills of the 1904 crop. A 

 similar check to that of the preceding year was also planted. In 1906 

 the same policy was pursued, the results reported thus representing three 

 years of selection. The following table quoted from Mr. Wade's report 

 summarizes the results clearly. 



Summary of Results from Use of Seed Potatoes from High-Yielding Hills 



AND from Low- Yielding Hills. 



(I 'arid y, Caniiaii Xo 3.) 



1 C. W. Wade, " Results of Hill Selection of Seed Potatoes," American 

 Breeders' Association, Vol. HI, 191-198 (1907). See also Bull. 174, Ohio Agri- 

 cultural Experiment Station. 



