394 BULLETIN No. 127. [August, 



The seed is planted in a hot house in February and transplanted 

 twice before planting in the open after danger of frost is over. 

 Fraser (37 p. 174) believes the old idea of this first year crop con- 

 sisting of small tubers does not always hold and states that a 

 tuber weighing over seven ounces has been grown the first year. 

 He says, "The Burbank potato was full size the first year it was 

 grown from seed, and many breeders feel that unless the tubers are 

 of edible size the first year that they are not likely to be worth fur- 

 ther care." Girard (45) also states that with proper cultivation, 

 seedlings will produce marketable tubers in one or two years. 



I have seldom seen a marketable tuber produced by even a two 

 year seedling, and think that such results must be unusual. The 

 vines certainly often reach full size the first year, but the growth is ' 

 almost entirely vegetative with very little matter stored in the 

 form of tubers. The vines producing the larger tubers seldom pro- 

 duce a large number, and I have been told by several reliable breed- 

 ers that they prefer, the first year as well as subsequent years, 

 to select the vines having the largest number of tubers. And while 

 there are no comparative data, the use of the plant as a whole as a 

 selective unit appears the more reasonable. The great majority of 

 the seedlings produce tubers of only one to fifty grams weight the 

 first year and require three years to reach their full size. It is also 

 noticeable that the typical shape of the strain is not generally 

 shown the first year, the tubers at this time generally being round 

 in shape. 



PRECAUTIONS IN COMPARATIVE TESTS 



After the first year the elimination of the unfit begins. The 

 tubers from the ^year before are compared in the garden in short 

 rows and as elimination goes on the best are given field trials. In 

 carrying out all field and garden comparison tests, there are a great 

 number of factors which have an influence upon growth, and which, 

 as far as possible, must be taken into account; for a field test at 

 best has a large experimental error and the error with potatoes is 

 probably larger than with any of the seed propagated annuals. 



The more common operations of all field experiments which 

 first come to mind and which scarcely would be neglected in the 

 comparison, are absolute uniformity in the time of planting, num- 

 ber of times and methods of cultivation and spraying, kind and 

 amount of fertilizer, and time of harvesting after dividing the va- 

 rieties into early, medium and late maturing. There are a number 

 of other points which have been neglected in far too many potato 



