208 Diseases of Truck Crops 



by a blackening and decaying of the stem; see 

 also p. 190. Kale is also attacked by club root Plas- 

 modiophora brassica Wor., see p. 1 86. 



DISEASES OF THE MUSTARD (Brassica 

 Japonicd) 



Garden mustard Brassica Japonica is cultivated 

 for its foliage. It is used as a green, relished for its 

 edible qualities, and as a spring tonic. Mustard is 

 subject to the following diseases: 



BLACK ROT, see CABBAGE, p. 190. 



CLUB ROOT, see CABBAGE, p. 186. 



WHITE RUST (fig. 35 b-e), see RADISH, p. 193. 



DISEASES OF THE RADISH (Raphanus sativus) 



Radish is subject to many diseases in common with 

 the cabbage and numerous other crucifers. 



CLUB ROOT, see CABBAGE, p. 186. 



BLACK ROT 

 Caused by Pseudomonascampestris (Pam.) Ew. Sm. 



Black rot on radish is confined mostly to the tender 

 white-rooted varieties, especially the Icicle. The 

 black-rot germ penetrates the lateral feeding rootlets, 

 from which it works its way in the main root. In 

 cutting across a diseased radish, its interior fibro- 

 vasculaf bundles are found to be blackened. Such 



