BUREAU OF PLANT INDUSTRY. 411 



and improvement. The bearing of present methods of growing hops 

 on yield will continue to receive attention, since important problems 

 along this line remain to be solved. The great importance of a study 

 of the constituents of hops in relation to the market value seems to 

 be clear, and this type of work is required in order to develop a 

 method of judging the value of the product; consequently the work 

 in progress bearing on these problems is to be continued. 



Tea investigations. — The work on the tea experiment was very 

 satisfactory, the result being a large yield of high-grade tea. Dr. 

 Charles U. Shepard, with whom the department is in cooperation, 

 found an increasing demand for more American tea than he was able 

 to furnish. The pruning machine designed by Mr. Geo. F. Mitchell, 

 by its rapid and uniform operation, seems to have become a standard 

 addition to the equipment of the tea plantation. The working out 

 of a picking machine has been begun, with promising results. The 

 perfection of tliese types of labor-saving machinery is very im- 

 portant, not alone to reduce the cost of production, but also to attain 

 results with promptness and regularity. 



The tea work of the ensuing year will continue the development 

 of labor-saving machinery and the study of the relation between 

 weather conditions, methods of cultivation, etc., to tea yield. 



POISONOUS-PLANT INVESTIGATIONS. 



As heretofore, the investigation of poisonous plants has been car- 

 ried on chiefly in the grazing regions of the West. Field feeding 

 experiments with plants suspected of being harmful were carried out 

 by Dr. C. D wight Marsh and his assistants. A temporary camp was 

 established near Baldwin, Colo., with the cooperation of the Forest 

 Service, and a number of suspected plants were carefully studied. 

 It was thought desirable to extend the investigations to include im- 

 portant sources of trouble in southern Montana, and a camp was 

 located near Greycliff, Mont., where suspected plants are found, and 

 work with death camas, lupine, and other species was begun. 



Larkspur poisoning. — Chief among the plants supposed to cause 

 damage in the mountainous country are species of Delphinium (lark- 

 spur). A thorough study of the several species occurring near Bald- 

 win, Colo., was completed, with special reference to the action on 

 cattle. The larkspur situation, as far as the field work is concerned, 

 is likely to be cleared up this year and will receive only incidental 

 attention in the future. 



Lupine poisoning. — Many stockmen have regarded species of Lu- 

 pinus (lupine) as harmful to domestic animals, an opinion which 

 preliminary experiment seemed in a measure to warrant. This 

 group of plants received attention at the camp in Montana, where a 

 sufficient supply of several species was available. It is probable that 

 the eflFect of lupine feeding on the various kinds of range animals 

 will be an important feature of the work of the coming fiscal year. 



Death-camas poisoning. — Another ])roblem believed to be very im- 

 portant deals with the harmful properties of Zygadenns spp. (death 

 camas). Some of the most injurious sorts were to be found in the 



