REPORT OF THE SECRETARY. 131 



improvement and development of the farm as a field laboratory for 

 the Department of Agriculture was seriously started in 1900. Sur- 

 veying, grading, and draining operations were begun the first year. 

 Since then the present equipment, consisting of two dwellings, a 

 large barn, shop, tool storage and boiler house, greenhouses, tool 

 sheds, drug laboratory, and refrigcratmg plant, has been installed. 



Previous to 1901 all the attention given to the vegetable crops 

 originated in the Division of Pomolog}'. Coincident with the devel- 

 opment of the Arlington farm activities along the lines of market 

 gardening, truck farming, and vegetable gardening were undertaken. 



The Irish-potato investigations are to-daj^ represented by a chain 

 of field stations located in Maine, New York, Virginia, West Vir- 

 ginia, Michigan, Wisconsin, Minnesota, North Dakota, Nebraska, 

 Colorado, California, and Idaho, which have been developed since 

 1903. Varieties of potatoes have been obtained from Europe and 

 from South America, in addition to those common in the American 

 trade, to test their disease resistance. Tests are under way to deter- 

 mine the adaptation of varieties to special localities for commercial 

 purposes, as well as to determine those localities that can most eco- 

 nomically produce seed of superior merit for regions which have to 

 depend upon a foreign seed supply. The hill-selection and tuber- 

 unit method of breeding potatoes for maintaining the vegetative vigor 

 and productivity of our standard sorts has been improved and has 

 given remarkable results in some regions where crop failures have 

 been a severe blow to the potato industry. 



The sweet-potato investigations, which were undertaken about the 

 same time as the Irish-potato investigations, have resulted in deter- 

 mining the identity of varieties and have developed a method of 

 utilizing the sweet potato for stock food which needs only to be car- 

 ried to those regions where sweet potatoes can be cheaply produced. 

 At the present time an effort is being made to solve the storage prob- 

 lems of sweet-potato growers. 



The peanut investigations, which were begun in 1905, have proved 

 of great advantage to the boll-weevil districts of the South by carry- 

 ing to these regions a money crop of as great value as cotton, thus 

 increasing the desirability of establishing a crop-rotation system. 

 The invention of machinery that takes the place of hand labor in 

 digging and picking the nuts has removed the industry from one 

 confined to small areas, because of labor restrictions, to an industry 

 which can be conducted on as extensive a scale as potatoes, beans, or 

 other crops which require similar handling. 



At the beginning of these investigations no peanut-oil industry 

 existed in America. At the present time several of the cotton mills 

 located in the peanut-producing area are installing machinery for 

 the expression of peanut oil. Coincident with the expansion of the 



