STEWART'S DISEASE OF SWEET CORN (MAIZE). 



Maryland, 8 miles from the experimental grounds of the Department of Agriculture. The 

 variety was Cosmopolitan and was grown from seed obtained from the Department of 

 Agriculture. Mrs. Brown said the variety came up badly and some stalks died while small. 



This plant was about 3.5 feet high, with three suckers. The main stalk had a dead- 

 white inflorescence (all of the flowers were dead and also the upper part of the rachis). 

 The stem was green, but every leaf on the plant was dead or dying. The death of the leaves 

 began with the lower ones, and the cause was not apparent on the surface. 



When the stem was cut 4 inches from the base, there was a copious yellow ooze 

 from the vessels. I cut it 5 inches 

 under the male inflorescence and 

 found yellow bacteria there also, 

 but less abundant. The base of 

 the stem, when slit longitudinally, 

 showed brown nodes and white 

 ink-modes, with yellow and brown 

 bundles. Two of the suckers ap- 

 peared to be healthy. The bundles 

 of the third sucker at a foot from 

 the ground contained the yellow 

 bacteria in abundance. 



It seemed likely that the dis- 

 ease was introduced into this garden 

 on the seed, and an inquiry was 

 made as to its origin. It formed 

 part of the Congressional Seed Dis- 

 tribution of the spring of 1 903 . f It 

 was bought from a reputable seed 

 firm in Philadelphia, for whom it 

 was grown under contract by a 

 seedsman in Ohio. A large amount 

 had been contracted for, but only a 

 small quantity was furnished. The 

 reason for this failure to deliver the seed is given in the following letter of November 5, 

 1902, addressed to Mr. A. J. Pieters, of the Department of Agriculture: 



DEAR SIR: We regret extremely to have to advise you that yesterday's mail brought a letter 

 from the grower of the Cosmopolitan sweet corn stating that this variety is rotting and he will only 

 be able to deliver 20 per cent of the quantity ordered. 



Our last previous report on this variety was 80 per cent and it is very disappointing to now be 

 advised of such a terrible "fall down." 

 Yours very truly, 



On inquiring as to where I could find more sweet corn grown from this same suspicious 

 seed, Mr. Pieters told me that he had himself directed some of it to be planted along with 

 many other varieties for a trial test on the Potomac Flats (one of the Department farms) 

 south of the Washington Monument. An inspection of these trial plots by the writer 



Fie. 46. A detail from fig. 45, showing in cross-section a vascular bundle from a corn-cob, the xylem part of 

 which is occupied by Bacterium stewarti. 



t Also in 1913, Mrs. Enlows, one of my assistants, found this disease at Parsons, West Virginia, in sweet corn 

 grown from seed distributed by the Department of Agriculture (Congressional Sjed Distribution of 1913). 



Fig. 46.' 



