BROWN ROT OF SOLANACEAE. 



175 



GEOGRAPHICAL DISTRIBUTION. 



This disease occurs in Colorado (?) Arizona (?), New Mexico (?), Texas, Mississippi, 

 Alabama, Florida, Georgia, South Carolina, North Carolina, Maryland, Virginia, New 

 Jersey, and apparently as far north as middle New England. It probably occurs also in 

 Ohio and in Illinois and other States in the middle and far west, but its northern and its 

 western distribution have not been worked out. Clinton has reported it from Connecticut. 

 It is found in America as far south at least as Porto Rico, the writer having received it from 

 that island in tomatoes and egg-plants. This disease, or one suspiciously like it, has been 

 reported from near St. Petersburg, Russia, and from various parts of Great Britain, France, 

 and Italy. In all probability the disease occurs in many parts of Europe. Hunger has 

 reported it from Java and Sumatra. Tryon has also stated (1899) that this disease is the 

 same as one found by him in Australia (see Appendix p. 207) . What appears to be the same 

 disease occurs, it is said, on potatoes and tomatoes in Umtali, Rhodesia, South Africa. 

 The disease probably occurs in Japan. 



SIGNS OF THE DISEASE. 



Both the sleepy disease of tomatoes (Fusarium), and the Grand Rapids disease 

 (Aplanobacter) , cause tomato plants to wilt suddenly, and therefore they might be confused 



easily with this disease. On potato 

 both here and in Europe it might be 

 confused with some forms of the 

 ' ' black leg " or " sch warzbeinigkeit ' ' 

 described by Appel as due to Bacil- 

 lus phytophthorus, by van Hall as 

 due to Bacillus atrosepticus, by Pril- 

 lieux and Delacroix as due to B. 

 caiilivorus, and by Pethybridgc and 

 Murphy as due to Bacillus melan- 

 ogenes. There is also a potato disease 

 in France attributed by Delacroix 

 to Bacillus solanincola (see p. 214). 

 The foliage becomes prema- 

 turely yellow and dies gradually (pi. 

 24, fig. 3), or wilts suddenly without 

 loss of green (pi. 25), and in large 

 \J ^-^tO)^^^^ leaves of the tomato the main axis of 



the leaf is also often bent downward 

 in a characteristic way (plates 26, 

 27, 28) ; the stems droop and shrivel 

 when not too woody (pi. 24, fig. 1) ; 

 and there is usually a decided brown stain in the vascular system in advance of the death 

 of the external parts. The vessels of such stems are filled with enormous numbers of the 

 small termo-like bacteria, which are not sticky and which ooze out of the stem on cross- 

 section as a dirty white or brownish-white slime. The bacteria pass up and down the 

 stems considerably in advance of the shriveling, and the accompanying brown stain can 

 often be seen through the younger and more translucent stems and petioles, especially of 



footnm 



Fig. 81. 



*Fig. 81. Root of a diseased egg-plant from Porto Rico, sound externally but browned within and showing in 

 cross-section three vessels of the vascular system occupied by bacteria. Received June 8, 1905, and drawn with the 

 Abbe camera, unstained, from a free-hand section, the bacteria dragged over by the knife being omitted. The root 

 was about 5 mm. in diameter: Its actual diameter is shown by the small circle at the left. 



