10 BULLETIN 40, TJ. S. DEPARTMENT OF AGRICULTURE. 



SUSCEPTIBILITY OF SOLANACEOUS PLANTS TO THE DISEASE. 



Although Mayer 1 established many important facts concerning 

 the mosaic disease, he states that he did not succeed in communi- 

 cating the disease from tobacco to other solanaceous plants. 

 Westerdijk 2 has also reported that the mosaic disease of tobacco 

 is distinct from the mosaic disease of tomato. By actual experi- 

 ment Clinton 3 first proved conclusively that the mosaic disease of 

 tobacco was communicable to healthy tomato plants, and vice versa. 

 The writer's experiments indicate that the two diseases are identical 

 and likewise communicable to the same plants throughout the 

 solanaceous family. The writer has readily transferred the disease 

 from tobacco to a great variety of solanaceous plants. By inocula- 

 tion the disease has been obtained in the following genera: 



In Nicotiana (all varieties of A 7 , tadacum tested and many distinct 



species of Nicotiana). 

 In Lycopersicon (several of the more distinct varieties of tomato). 

 In Petunia (Petunia violacea). 

 In Physalis (two distinct garden species). 

 In Datura (D. stramonium and D. tatula). 

 In Hyoscyamus (H. niger). 

 In Solanum (8. nigrum and 8. carolinense) . 

 In Capsicum (several of the more distinct varieties). 



Both in the greenhouse and in the field natural agencies produce 

 the disease in practically all the plants mentioned. 



A mosaic plant of the species Solanum carolinense brought to the 

 writer's attention indicates that the mosaic disease of tobacco some- 

 times occurs in strictly wild plants. 



In the genera Solanum and Atropa, although the methods used to 

 inoculate these plants were particularly severe, all efforts to inocu- 

 late the common potato (Solanum tuberosum), the eggplant (So- 

 lanum melongena), and belladonna (Atropa belladonna) have failed 

 to produce any visible evidence of the disease. 



In the genus Datura some species appear to be considerably more 

 resistant than others to the mosaic disease of tobacco. The disease 

 may be communicated to D. stramonium L., D. tatula L., and D. 

 quercifolia H. B. and K. The most persistent and rigorous methods 

 of inoculation have failed to produce any symptoms of mosaic in 

 the species D. fastuosa L. 



1 Mayer, Adolf. Ueber die Mosaikkrankheit des Tabaks. Die Landwirtschaftlichen 

 Versuchs-Stationen, Bd. 38, p. 450-467, pi. 3, 1886. Abstract in Journal of Mycology, 

 ▼. 7, no. 4, p. 382-385, 1894. 



2 Westerdijk, Johanna. Die Mosaikkrankheit der Tomaten. Amsterdam, 1910, 19 p., 

 3 pi. (Mededeelingen uit net Phytopathologisch Laboratorium " Wille Commelin Schol- 

 ten," Amsterdam, 1.) 



3 Clinton, G. P. Notes on fungous diseases, etc., for 1908. Connecticut Agricultural 

 Experiment Station, Biennial Report, 1907/1908, p. 857-858, pi. 66, fig. 6, 1909. 



