GRAND RAPIDS TOMATO DISEASE. 



I6 5 



It is Gram positive. Only one of three tubes clouded after 10 minutes' exposure in 

 + 15 peptone-bouillon at 45 C, and that slowly. Repeated with same result. Endures 

 drying well (cover slips 45 days). Slowly loses virulence on media (several years) . Viscid 

 on potato and agar. Some sugared fluids also became very viscid. Group No. 21 1.2222522. 



NEGATIVE. 



Organism non-motile, non-sporiferous. It does not produce gas, or grow in the closed 

 end of the fermentation tube: tests made in peptone water with grape-sugar, cane-sugar, 

 fructose, lactose, galactose, maltose, mannit, glycerin. No immediate acid from lactose, 

 galactose, maltose, mannit or glycerin. No liquefaction of Loeffler's blood serum. No 

 prompt liquefaction of gelatin. It does not cloud +15 peptone bouillon after 10 minutes 

 exposure at 47 , 48 or 5oC. It is not acid fast. It does not reduce potassium nitrate. 

 It does not grow in Cohn's solution or in Uschinsky's solution. No growth in neutral 

 peptone beef bouillon acidified to +20, +25, or +30 with malic, citric, or oxalic acid. 



When this organism was first discovered the writer thought he observed motility, but 

 many subsequent examinations have shown it to be non-motile. The name should be 

 changed, therefore, from Bad. michiganense to Aplanobacter michiganense. 



Striking characteristics are copious yellow surface growth on milk, and very slow growth 

 in agar, gelatin and bouillon, containing Witte's peptone and beef juice, with sodium hy- 

 drate to read + 10 or +15 on Fuller's scale. Viscidity on agar, and potato is common. 

 For litmus milk and potato, see pis. 1 1 and 44. Because Apl. michiganense has same group 

 number as Apl. rathayi, some comparisons were instituted with the following results: 



Apl. michiganense. 



Potato : Streaks pale yellow, 



smooth, inclined to spread. 

 Gelatin (+14, plates at 20 C. 15 



days) : Many colonies. 

 Peptone beef-bouillon (+14, at 20 



C. 6 days) : Thinly clouded, no 



pseudoz oogloeae . 

 Litmus milk (15 d. at 27 C): 



redder than check, i. e., dull 



heliotrope-purple (Ridgway). 

 Inoculations: Causes disease of 



tomato (signs in 10 days). 



Apl. rathayi. 



Streaks darker yellow, inclined to 



pile up and wrinkle (Fig. 75 a). 

 No colonies. In a repetition it 



grew on +9 gelatin. 

 No clouding, hundreds of pseudo- 



zoogloea on walls and bottom of 

 tubes. 

 Bluer than check. Less surface 



growth, more yellow precipitate. 



Not infectious to tomato (3 ex. : 45 

 days, 39 days, 26 days). 



LITERATURE. 



Fig. 75a. 



1892. Lodeman, E. G. A new disease of the tomato. 

 Garden and Forest, vol. v, p. 175. 



A brief note, which probably belongs here. 



"We thought that this bacterium might be identical with 

 the one which is sometimes so destructive to potatoes, for the 

 appearance of the disease in the two plants is similar, but Prof. 

 Burrill, to whom specimens were referred, has just reported 

 that the two diseases are probably distinct. It is certain 

 that the disease can be communicated to the potato, for dis- 

 eased tomato-cions have been grafted upon healthy potato 

 plants and the latter are now plainly affected. 



******* 



"Possibly this serious disease is identical with the Southern 

 Blight, recently reported by Dr. Halsted in a bulletin of the 

 Mississippi Experiment Station." (See bibliography, p. 216.) 



1892. Bailey, L,. H. Winter blight, in "Some 

 troubles of winter tomatoes," Bull. 43, 

 Cornell Univ Agrie. Exp. Sta., Ithaca, N. Y., 

 1892. See also Am. Gardening, 1892, p. 668. 



Relates to the disease first mentioned by Lodeman, of 

 Cornell, and probably belongs here. The very slow growth 

 of the parasite on agar poured plates as shown by our studies 

 would account for Dudley's failure to get it in his cultures from 

 diseased tomatoes. Interesting also is the fact that when a 

 diseased cion of tomato was grafted on potato the stock became 

 affected and contained bacteria. Also, the fact that the 

 disease spread very quickly from diseased to healthy adjacent 



plants in the same compartment of the hothouse, but not to 

 tomato plants in another compartment. This second com- 

 partment was connected with the first by two doors, allowing 

 free access from one room to the other, but the plants were 

 separated by a glass screen, which would catch and hold back 

 the bacteria likely to be spattered from the diseased plants by 

 the gardener's hose (see this chapter, p. 163). The cloudy 

 white organism which Dudley obtained from the potato and 

 identified as a micrococcus may be assumed to have been 

 some saprophyte- Specimens of this disease were sent to 

 Dr. Halsted who replied that it was not the Mississippi disease. 



1892. Bailey, L. H., and Corbett, L. C. Southern 

 or field blight in "Tomato Notes for 1892." 

 Bull 45, Cornell Univ. Exp. Sta., Ithaca, 

 N. Y., 1892, p. 213. 



Seems to relate to a field disease, but probably belongs here 

 rather than under Southern blight. The figure is suggestive, 

 and also a statement in the text respecting the irregular drying 

 out of individual leaflets. 



1910. Smith, Erwin F. A new tomato disease of eco- 

 nomic importance. Science, n. s., vol. xxxi. 

 No. 803, May 20, 1910, pp. 794-796. 



Abstract of a paper read in Boston, December 1909, before 

 American Phytopathological Society. The first account of the 

 organism, but probably not the first account of the disease, as 

 was then supposed. 



*Fig. 75 a. Streak cultures on potato: (1) Aplanobacter rathayi; (2) Apl. michiganense. Time 14 days; 

 temperature 20 C. Both will grow on potato at i C. 



