192 Diseases of Truck Crops 



of water. In making the seed bed, manure known to 

 be free from cabbage refuse should be used. All insect 

 pests should be kept in check by spraying, and no 

 . animals should be allowed to roam in sick patches. 

 Insects and farm animals act as carriers of black 

 rot. The disease cannot be controlled by merely 

 cutting off diseased foliage. If anything, this 

 operation aggravates the trouble. Diseased plants 

 should be pulled out and destroyed. Crop rotation 

 should be practiced wherever the disease is well 

 established. 



Soft Rot 



Caused by Bacillus carotovorus Jones. 



Soft rot, although a field trouble, causes great 

 damage to stored cabbage. The greatest losses 

 are reported from New York and Wisconsin where 

 cabbage is stored on a large scale. 



Symptoms. The disease is ^characterized by a soft, 

 mushy to slimy decay of the entire plant. The dis- 

 ease works very rapidly under favorable conditions 

 of moisture and temperature. The causal organism 

 can gain entrance only through a wound or bruise. 

 Rough handling of the crop during hauling and stor- 

 ing therefore opens the way to heavy infection and 

 consequently loss from soft, rot. 



The Organism. The Bacillus is rod-shaped, long 

 or short, and usually formed in chains. It moves 

 about by peritrichous flagella. It completely lique- 



