STEWART'S DISEASE OF SWEET-CORN (MAIZE). 



147 



The disease is on the increase in the United States and has been, I believe, disseminated 

 widely in recent years by ignorant and unscrupulous seedsmen. It is likely to be found now 

 in any State. 



HISTORY. 



The history of this disease begins with Stewart's bulletin (1897), unless we are to assume 

 that BurrhTs bulletin "On a bacterial disease of corn" (1889) relates in part to the same 

 subject. I have not included the latter in the bibliography 

 of this disease, although perhaps I should have done so. 

 Some parts of his description correspond very well to 

 Stewart's disease, c. g., irregular distribution of the disease 

 in the field; dwarfing; brown nodes; the base of the stalk 

 most badly affected ; death of the leaves as a whole, the 

 lowest showing worse; and gumming of the ears; but if he 

 really had this disease under observation, why is there no 

 mention of the most conspicuous sign, i. c, yellow slime in 

 the internodal bundles? The internodes appeared to him 

 to be healthy in plants having the browned nodes. Along 

 with these signs, as part of the same disease, are mentioned 

 other less characteristic signs, i. c, decaying roots, the 

 lower ones most affected ; corroded spots on the roots ; 

 brown spots on the leaf-sheaths, most conspicuous within, 

 and occasionally bordered by red. These brown spots 

 are "half rotten" discolorations, the disease in this stage 

 being evenly distributed through the field. There is a 

 gelatinous bacterial substance on the roots and inside the 

 leaf-sheaths. The description of the organism which he 

 isolated and with which he obtained infections is what 



finally decided me to exclude it. This was a white peritrichiate schizomycete subse- 

 quently identified by Dr. Theobald Smith as Bacillus cloacae. 



Fig. 64 a.* 



LITERATURE. 



1898. Stewart, F. C. A bacterial disease of sweet 

 corn. New York Agrie. Exp. Sta. Bull. No. 

 130, Dec. 1897, pp. 423-439, plates i-iv, 

 Geneva, N. Y. [Bull, distributed in Jan. or 

 Feb. 1898] 



Reprinted in 16th Ann. Rept. Bd. of Control N. Y. Agric. 

 Exp Station for 1897, pp. 401-416. 



1898. Smith, Erwin F. Notes on Stewart's sweet- 



corn germ, Pseudomonas stewarti, n. sp. Proc. 

 Am. Assoc. Adv. Science, vol. 47, meeting at 

 Boston, Aug. 1898. Published at Salem, Dec. 

 1898, pp. 422426. 



Also a separate. 



1899. Halsted, Byron D. Sweet corn smut and bac- 



terial disease, in Mycological Notes, Torrey 

 Bull., New York, Feb. 1899, p. 77. 



Reports occurrence in 189S of bacterial disease due to Pseu~ 

 domonas steu'arii in one variety of sweet corn at New Brunswick. 

 N.J. 



1901. Smith, Erwin F. The cultural characters of 

 Pseudomonas hyacinthi, Ps. campestris, Ps. 

 phaseoli, and Ps. stewarti Four one-flagellate 

 yellow bacteria parasitic on plants. Bull. 28., 

 Div. of Veg. Physiology and Pathology, U. S. 

 Dept. Agric, Govt. Printing Office, Washing- 

 ton, D. C, 1901. 



1903. Smith, Erwin F. Completed proof that Ps. 

 stewarti is the cause of the sweet-corn disease 

 of Long Island. 



Abstract of an address delivered Dec. 30. 1902. before the 

 Society for Plant Morphology and Physiology. Science, n. s., 

 vol. xvu. No. 429. March 20, 1903. Also a separate. 



1909. Smith, Erwin F. Seed corn as a means of dis- 

 seminating Bacterium stewarti. Science, n. s., 

 vol. xxx, No. 763, Aug. 13, 1909, pp. 223-224. 

 [See also various figures and observations in vols. 

 I and II of this monograph.] 



*Fig. 64a. Pedicel of ear of sweet corn, showing bacterial ooze from stomata at X X. Experiment of 1908. 

 Photographed from alcohol in 1914, X6. Originally the cirri were much more conspicuous and then also water-soaked 

 places were visible on the surface. See text, p. 126. 



