1913.] PUBLIC DOCUMENT — No. 31. 51 



will 1)0 mosaic to a greater or less extent. A badly aiTeeted 

 plant is worthless. 



11. Shade-grown tobacco is less liable to the disease than 

 ordinary field-grown, as a more nniform growth is obtained. 



12. Great care should be used to remove the plants from the 

 seed bed when the soil is moist, as thereby the roots are less 

 liable to injury and few are broken. They should not be al- 

 lowed to dry out. 



13. Thorough and timely cultivation will do a great deal 

 towards the prevention of this disease. 



14. Careful seed selection and separation will also help the 

 grower by giving him stronger and more vigorous plants. 



In conclusion it may be said that if care is used and sufficient 

 attention paid to all stages of the growth from the time the seed 

 is planted until the plants are mature, and the results studied 

 and acted on rationally, the amount of mosaic will be greatly 

 lessened, and, in fact, practically eliminated from the field. It 

 should be understood, however, that under adverse conditions, 

 such as unsuitable soil, etc., one cannot expect to eradicate this 

 trouble. 



In a future paper will be taken up the more detailed and 

 technical work performed by us in the study of this trouble, 

 also additional notes on similar diseases of other economic 

 plants. 



Bibliography, 



(1) Woods, A. r., "Mosaic Disease of Tobacco," U. S. D. A., Bur. 



Plant Ind., Bui. No. 38. Centralblatt fiir Bakteriolog-ie, Para- 

 sitenkunde und Iiijekfionskrankheilen, Abt. 2, Band V, 1899. 

 Science, n. s., 11, No. 262, pp. 17-19. 



(2) 0. Suzuki, Bui. Coll, Agi\, Imperial University, Tokyo, IV, Nos. 



3 and 4, July. 1900. 



(3) Beijerinck, " Veiliandlungen dor Koninklyke Akademie von 



Wetensehappen te Amsterdam," 1898. 



(4) Loew, 0., " Catalase," T^ S. D. A., Kept. No. C8. 



(5) Jensen, From A. F. Woods' Bui. No. 18 and Loew, Kept. No. 68, 



(6) Mayer, Landw, Versuchstation, 1880, Vol. XXXIL 



(7) Beijerinck, Loc. cit. 



(8) Woods, A. F., Loc. cit. 



(9) Sturgis. W. C, Ann. Kept., Conn. Exp. Station, 1898. 



(10) Stone, G. E., " Seed Separation and Germination," Mass. Agr. 

 Exp, Station, Bui, No, 121. 



