184 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



Madame Plantier, Seven Sisters, Wax Eose, Ragged Robin, Rosa 

 cinnamiwiea, Rosa setigera, and Bosa rur/osa. , 



While the larger part of the investigations is carried on at the 

 liell station, work on a smaller scale has b en located at the 

 Soutli Haven substation of the Michigan Agricultural Experijiient 

 Station, in cooperation with the latter, and at Norfolk, Va., in co- 

 operation with the Virginia Truck Experiment Station. 



VEGETABLES. 



POTATOES. 



Neu' varieties. — From the high Andes of Colombia and Ecuador 

 a considerable series of interesting potatoes has b' en introduced for 

 the use of North American plant breeders who are working with 

 this crop. This series includes a number of varieties of the chaucha 

 group, a very ( arly maturing type from Ecuador ; the yellow-fleshed 

 potato, a variety of remarkably rich flavor from Colombia; and one 

 or two wild forms closely allied to the cultivat d potato and of pos- 

 sible value for hybridizing with the latter. 



Improvement of seed stock. — About 5,000 new seedlings obtained 

 in the breeding work are under test, together with a considerable 

 number of the most promising selections made from earlier breeding 

 work. In this phase of the work the difficulty is to get in a single 

 combination high yield, high table quality, resistance to disease, and 

 the other important charactrristics of shape, smoothness of surface, 

 etc. In many instances seedlings that are highly rt sistant to diseasa 

 have proved to be light-yielding sorts and have lacked in table 

 quality or in some other particular, while other seedlings which 

 have had great promise in some other line have proved susceptible 

 to disease. The work is continued in the expectation that through 

 a combination of varieties of seedlings having desirable characteris- 

 tics in the largest degree seedlings will eventually be secured in 

 which these characteristics are all combined in a satisfactory measure. 



Perhaps the most immediately important and far-reaching ac- 

 tivity is that having to do with the improvement of seed stock. 

 By bringing together at certain places sample stocks of the seed 

 supplied of the different varieties which are largely grown for com- 

 mercial purposes and testing them under uniform conditions, it 

 becomes possible to determine what strains or selections are the most 

 nearly free from disease and give the best yield. Through this 

 method of testing under uniform conditions it is found that many 

 of the commercial seed potatoes supplied, even where the stock has 

 been certified, are more or less seriously diseased; and, further, there 

 is a very wide difference in the yield of different strains or different 

 selections of the same variety. For example, at Baton Rouge, La., 

 where Nebraska dry-land-grown Triumph seed stock was compared 

 with locally purchased seed of the same variety, the former showed 

 an increase of nearly 96 per cent in the product as compared with the 

 locally grown seed. Nebraska irrigation-grown seed gave an in- 

 crease of nearly 73 per cent, and Wisconsin-grown seed an increase 

 of more than 82 per cent over locally grown seed. The assembling 

 for testing and the selection of the highest yielding strains and 

 those that are the most nearl}' free from disease can be carried on 



