BUREAU OF PLANT INDUSTRY. 157 



ous methods and apparatus ordinarily used by the grain trade and 

 inspection departments to reduce the original sample to a portion 

 sufficiently small for convenient and rapid analysis disclosed the 

 fact that there was no apparatus on the market which would do the 

 dividing accurately enough for consistent results. In order to pro- 

 vide a reliable mixing and sampling device for the determination 

 of the proper grade of grain, a special device was designed and a 

 patent applied for which, if granted, will be for the free use of the 

 peox^le of the United States. 



Application of acidity test. — An improved method of determining 

 grain acidity, developed in connection with determination of the 

 soundness of corn, has been extended to apply to other grains. Until 

 recently the method required from 16 to 20 hours to complete a 

 determination, but a modification of the method has been completed 

 whereby the determination can be made within an hour. 



Rice handling. — Investigations relating to the harvesting, han- 

 dling, storing, and grading of rice indicate that the milling quality 

 of rice is in a large degree dependent upon the protection given the 

 grain while in the shock and the variable weather conditions pre- 

 vailing during the harvest season. Experiments to determine the 

 breakage of rice indicate that only a very slight damage results 

 from handling and shipping. Factors considered in the commercial 

 grading of rough rice and of clean rice were studied with a view to 

 establishing definite standard grades thereof. 



INVESTIGATION OF QUALITY OF SEED. 



Seed mixing in gins. — One of the chief causes of deterioration in 

 cotton varieties is the mixture of seed at custom gins as they are 

 ordinarily operated. When seed containing a mixture of several 

 varieties is planted ideal conditions are provided for cross-fertiliza- 

 tion and rapid deterioration results. A method has been devised 

 whereby the extent to which mixing occurs at custom gins can be 

 determined with reasonable accuracy. Since the amount of mixing 

 is much greater and hence far more serious than is commonly sup- 

 posed, growers and ginners will be urged to cooperate to reduce this 

 objectionable condition to a minimum. 



Potato inspection. — The informal cooperation of pathologists of 

 this department in the movement for the improvement of seed po- 

 tatoes by State inspection and certification has aided its rapid 

 progress during the year. Particular attention is given to the newer 

 troubles disseminated through seed tubers, such as leaf-roll, curly 

 dwarf, mosaic, wilt, etc., and to other potato seed improvement prob- 

 lems. Much benefit to the potato industry is resulting from this 

 movement, through the production of better seed and increasing 

 interest in disease-control and marketing problems. 



Imported seed. — As a result of the disturbed condition in Europe 

 there has been a shortage in the supply of many seeds normally im- 

 ported and the quality of others has been poor. Less than one- 

 fourth as much hairy vetrh seed was imported in 1915 as in 1914. 

 Some of this has been badly adulterated with weed vetches, one im- 

 portation containing only 5 per oent of hairy vetch seed. At present 



