404 ANNUAL REPOKTS OF DEPARTMENT OF AGRICULTURE. 



laboratory studies of tlie physiology and life history of strains of 

 BacUlus radicicola in the hope of devising improved methods for the 

 propagation and distribution of pure cultures. 



Advisory corresjDondence regarding the improvement of farm water 

 supplies, ice ponds, and reservoirs, heretofore carried on, has been 

 discontinued. 



Investigations of the bacterial flora at Fallon, Nev., Logan, Utah, 

 and Riverside, Cal., as well as in the vicinity of Washington, D. C., 

 have been continued. Especial emphasis has been given to the decom- 

 position of cellulose, the fixation of atmospheric nitrogen, and the 

 nitrification of organic matter. Many new types of cellulose fer- 

 ments have been discovered. It is planned to continue the study of 

 the organisms causing the decomposition of organic material in the 

 soil and their nitrifying and nitrogen-fixing properties. 



ACCLIMATIZATION AND ADAPTATION OF COTTON, CORN, AND 



OTHER CROPS. 



The investigations directed toward the acclimatization and adapta- 

 tion of varieties of cotton, corn, and other crop plants that have origi- 

 nated in tropical countries have been continued under the general 

 supervision of Mr. O. F. Cook, assisted by Mr. G. N. Collins. Dif- 

 ferent branches of the field investigations are conducted by Messrs. 

 J. H. Kinsler, H. Pittier, and D. A. Saunders. Particular attention 

 is given to the adaptive characters, environmental reactions, methods 

 of breeding, and local adjustment of varieties of cultivated plants, in 

 order to determine the best methods of improving the crops, to 

 develop increased resistance to unfavorable conditions, diseases, and 

 insect enemies, and to extend the range of cultivation in the United 

 States. 



Change of policy in cotton-breeding work. — The general policy 

 of the cotton-breeding work has been modified gradually in the direc- 

 tion of giving more attention to the preservation and utilization of 

 superior varieties, instead of to the development and distribution of 

 new sorts. With several varieties planted in the same neighborhood 

 a process of mongrelizing is continually going on through crossing in 

 the fields and the mixture of seed at gins. The new plan is to en- 

 courage the exclusive planting of superior varieties, each in the re- 

 gion where it is best adapted. 



Organization or cotton growing on a community basis. — Study 

 of the problem of utilization of superior varieties of cotton has led to 

 a recognition of the fact that such varieties are of the most value in 

 well-organized communities wherein a single type is grown. Such 

 conditions afford the best prospects of avoiding mixture of seed at 

 gins or crossing in the field, of applying improved methods of cul- 

 ture and selection, and of producing a commercial quantity of high- 

 grade fiber. As a means of encouraging such organizations of cotton- 

 growing communities a new project for the cooperative growing and 

 marketing of cotton has been inaugurated. 



Simultaneous planting to avoid weevil injury. — -Further study 

 of the factors of weevil resistance has led to a recognition of simul- 

 taneous planting as an effective method of avoiding injury. It is 

 possible in this way to avoid the dangers of exposure to cold weather 



