BACTERIAL CANKER OF TOMATO I TECHNIC 



211 



FIG. 152. FIG. 153. 



FIG. 152. Tomato stems showing loss of color (whitening) and swelling 

 prior to the formation of longitudinal cankers. Plants inoculated for several weeks 

 below parts here shown, with Aplanobacler michiganense (round colony). Photo- 

 graphed May 3, 1917. Natural size. 



FIG. 153. Typical canker-crack on a tomato stem due to Aplanobacler 

 michiganense. Plant inoculated on the stem below the part here shown. 



natural crack or canker from which the yellow bacteria are oozing abundantly. 

 X 5. 



(2). Another green fruit from which the diseased pedicel has been removed. 

 On the darker parts of the scar are masses of the yellow bacteria which have pene- 

 trated into the interior of the fruit which is sound externally. 



Natural infections from a hothouse in Massachusetts. Received in September, 

 1915. These yielded a long series of pure culture inoculations. 



