BUREAU OF PLANT INDUSTRY. 339 



ARLINGTON EXPERIMENTAL FARM AND HORTICULTURAL 



INVESTIGATIONS. 



The general supervision of the Arlington Experimental Farm and 

 of the Horticultural Investigations has been continued as in previ- 

 ous years by Prof. L. C. Corbett, Horticulturist. The general plan 

 of the work of these branches has not been modified, but decided 

 progress and development have marked the year. 



THE ARLINGTON EXPERIMENTAL FARM. 



The value of the farm at Arlington as an adjunct to the bureaus 

 and offices of the Department conducting investigations is well at- 

 tested by the use being made of its facilities by the various branches 

 of the Department service. 



Work of various bureaus on the farm. — The investigations in 

 progress at the farm under the immediate control of the Forest Serv- 

 ice and the Bureaus of Entomology, Chemistry, and Soils, are for 

 the most part a continuation of work already under way. The For- 

 est Service, in addition to maintaining its osier willow holt, has 

 devoted much time and space to the problems of seed germination. 

 This work has been conducted in. the greenhouse at the farm. The 

 Bureau of Soils has also increased its work by inaugurating a series 

 of fertilizer tests to learn the effect of the three important elements of 

 plant food — nitrogen, phosphoric acid, and potash — both singly and 

 in combination on plant growth. The area occupied by these four 

 branches of the Department aggregates 15 acres. 



The Bureau of Plant Industry has increased its work on the farm 

 during the j^ear. Nineteen offices of the Bureau are conducting inves- 

 tigations on areas set aside for the purpose. About 85 acres are at 

 present required for this work, for which the farm provides facili- 

 ties such as tools, implements, and labor. The work of the Bureau on 

 the farm embraces cultural, seed selection, plant breeding, and patho- 

 logical problems with the principal forage, grain, fruit, and truck 

 crops, as well as special studies in seed production, plant nutrition, 

 and floriculture. 



Nursery work. — The nursery devoted to the propagation and cul- 

 ture of fruit trees for the variety orchard collection and the propa- 

 gation and culture of ornamental trees and shrubs for planting about 

 the grounds has been enlarged. During the winter about 4,000 apple 

 grafts and 18.000 privet cuttings were prepared and are now growing 

 in the nursery. There are also growing in this area about 5.000 orna- 

 mental shrubs, 8,200 ornamental trees, 5,150 fruit trees, 4,000 fruit- 

 tree seedlings to be used for stocks for grafting purposes, 450 bush 

 fruits, 1,000 seedling evergreens, and 1,840 herbaceous perennials. 



Greenhouse work. — The last two of the range of ten greenhouses 

 at the farm have been erected during the year, and the entire range 

 will be ready for occupancy at planting time this fall. During the 

 past year about 2,000 roses, 5,000 carnations, 4,000 bedding plants, 

 and 4,000 shrubs were propagated in the greenhouses. Many annual 

 flowering and vegotal)]o plants for the variety tests and other gardens 

 were also started in the houses and later transplanted to the open. 

 The study of blind versus flowering wood rose cuttings is being 



