BUREAU OF PLANT INDUSTRY. 267 



plant has been found that transmits to its offspring both rust resist- 

 ance and increased vigor in a marked degree. This plant is being 

 used with the best female plants to develop progenies of practically 

 rust-immune asparagus. The best breeding plants are being propa- 

 gated hj division to increase the output of resistant seed. The ex- 

 tension in the near future of this work to the Southern States is 

 planned. 



Demonstration spraying. — A very important line of work in the 

 demonstration spraying of cantaloupes and cucumbers is being started 

 this season in Florida and New Jersey. Large financial losses are 

 annually caused b}^ leaf diseases preventable by spraying, and in 

 many sections the industry has been given up because of these diseases. 



MISCELLANEOUS DISEASES. 



An investigation of ginseng diseases in cooperation with the Cor- 

 nell University Agricultural Experiment Station has been under- 

 taken. Malnutrition studies have been continued and two bulletins 

 giving the practical results of the work have been published through 

 the Virginia Truck Experiment Station at Norfolk, Va. 



The cowpea breeding work to secure varieties resistant to wilt and 

 root knot which are more productive and erect than the Iron has 

 been continued and this year the most promising strains are being 

 increased to provide for more extended trials next season. 



A plant-disease survey of the San Antonio, Tex., area has been 

 completed and a report on the work is in press. 



SOIL-BACTERIOLOGY AND WATER-PURIFICATION INVESTI- 



. GATIONS. 



The investigations in soil bacteriology and water purification have 

 continued in charge of Mr. Karl F. Kellerman. 



Work with nodule-forming bacteria. — Pure cultures of nodule- 

 forming bacteria for inoculating approximatelj'^ 25,000 acres of 

 leguminous crops were distributed during the fiscal year 1911. The 

 use of pure cultures is believed to be one method of avoiding the dis- 

 semination of crown-gall, which affects leguminous crops as well as 

 orchard trees. 



During the. fiscal year ending June 30, 1912, more detailed field 

 work will be taken up in connection with the experimental distribu- 

 tion of these pure cultures, and it is planned to continue the field 

 investigations in connection with the laboratory and field studies 

 upon the correlation of bacterial growth and crop production. 



Farm avater supplies. — Advisory correspondence in regard to the 

 improvement of farm water supplies has been carried on and in some 

 cases personal supervision of improvements has been undertaken. 

 This work will be continued and occasionallj^ supplemented by dem- 

 onstrations of simple methods for improvement during the present 

 and coming fiscal years. 



Studies in soil bacteriology. — Detailed studies of certain bacterial 

 conditions obtaining at Fallon, Nev., Logan, Utah, and in the vicinity 

 of Washington, D. C, have been carried on. These studies cover 

 the investigation of the relative nitrifying and nitrogen-fixing power 



