BUREAU OF PLANT INDUSTRY. 65 



agricultural land lias, through private ineaus, been secured in Cali- 

 fornia, with satisfactory water rights, which will supply the more 

 pressing present needs in a temporary manner. In addition to this 

 a small tract of ground suitable for propagating, near the Pacific 

 coast laboratory, has been secured in like manner, and this is access- 

 ible to a constant supply of city water, gas, sewerage, etc. Facili- 

 ties in the way of temporary lath house, tool house, potting house, 

 etc., are being placed on this property and will materially facilitate 

 the various lines of work. 



Pathological worl^. — The main lines of study during the year have 

 been bacteriosis of walnuts, the vine diseases in the Santa Clara Val- 

 ley, and the blight of loquats and pears. Many other plant diseases 

 of minor commercial importance have also received attention. 



MISSISSIPPI VALLEY LABORATORY AND INVESTIGATIONS. 



The work carried on by the Mississippi Valley laboratory for the 

 past j^ear was divided into two distinct lines: First, the investigations 

 concerning the decay of timber in live trees and in structural timber, 

 together with methods used for preventing the same; second, inves- 

 tigations concerning diseases of fruit trees. In the first line of work 

 cooperation was secured with the Bureau of Forestry. Dr. Hermann 

 von Schrenk is in charge of this laboratory. 



Investigations concerning tlie decay of timber. — This work has for 

 its primary object the securing of knowledge which will aid in con- 

 serving the amount of timber on hand. By preventing the pi'ema- 

 ture decay of wood it is possible to use not only the high-grade resist- 

 ant kinds mainly employed at the present time, but also the inferior 

 grades of wood which, under ordinary conditions, rot so rapidly as to 

 be practically worthless. The knowledge which we have at the iDres- 

 ent time as to the best methods of treating wood so as to prevent 

 decay is very fragmentary. During the past year special attention 

 has been given to the investigation of methods of treating wood with 

 a view to preventing its decay. This work as a whole involves not 

 on]}' extensive studies in regard to the causes of decay, but elaborate 

 experiments in the impregnation of timber with different materials, 

 with a vie'Av to determining cheap and effective methods of increasing 

 its length of life. Special attention has been given to a serious dis- 

 ease of catalpa, a tree now largely planted in all parts of the Central 

 and "Western States; also to a trouble known as "blue" disease of 

 pines. Nearly 600,000,000 feet of timber have been affected by this 

 blue disease in the Black Hills. The blue wood has been considered 

 unfit for lumber, mine timbers, or fuel, .and as a result this immense 

 quantity is being allowed to go to waste. Preliminary tests have 

 already shown that the blue timber is practically as strong as the 

 green wood and that its fuel value is scarcely less than that of the 

 sound wood. Should these preliminary conclusions be borne out, it 

 would mean the saving of many millions of dollars' worth of timber 

 to the United States Government and also directly to the States which 

 dej)end on the Black Hills as a source of timber supply. 



Investigation of tJie aiseases of fruit trees. — Experiments were con- 

 ducted in a number of orchards in Missouri and Illinois for prevent- 

 ing the bitter-rot disease of apples. In addition, the life history of 

 the bitter-rot fungus was studied, and the manner in which the fruits 



AGR 1902 5 



