20 U. S. DEPARTMENT OF AGRICULTURE. 



This disease is a soft rot characterized by a slimy, slippery 

 condition of the affected tissues, by a foul odor, and by the 

 absence of fungous growth. The last characteristic differ- 

 entiates it from rots caused by fungi. Green, leafy tissues 

 affected with slimy soft rot have a very dark green color at 

 first much like hashed spinach but later become brown and 

 black. Light colored tissues, such as cabbage and celery, 

 become yellowish and finally brown. 



Slimy soft rot is differentiated from gray mold rot by the 

 absence of the powdery, gray growth of mold and of the 

 gray to black sclerotia characteristic of gray mold rot. The 

 offensive odor of slimy soft rot distinguishes it from the rot 

 due to Rhizopus, which has an acid odor. Tissues affected 

 with slimy soft rot do not leak as do tissues affected with 

 watery soft rot, but become a mass of slime if kept in a 

 moist place. Watery soft rot progresses even in a dry 

 atmosphere after once well started, whije the progress of 

 slimy soft rot is arrested by drying of the tissues. 



The rot proceeds from any part of the plant, and tissues 

 are predisposed to it by bruising, chilling, freezing, tip-burn, 

 sun-scald or aging. In the case of the southern bunch crops, 

 only the leaves are affected. It is prevalent in root crops 

 whenever tissues have been killed by exposure to extremely 

 wet conditions, by extremely high temperatures, or by freez- 

 ing. During rainy seasons, slimy soft rot may ruin southern 

 potatoes if they are not dug at once and dried. Future inves- 

 tigations may show that the slimy soft rot of the leafy parts, 

 and the soft mushy rot of the root or stem parts of plants, 

 well marked in carrots and cabbage, are not caused by the 

 same organism. The rot of the latter sometimes is called 

 the "true soft rot." In carrots that have been in storage, 

 soft rot is often found, the central tissue of the root being 

 most readily attacked. In the north, soft rot is common in 

 cabbage in the field late in the fall, especially where many 

 plants have been weakened or killed by the soil disease 

 known as cabbage yellows. Such rotted heads in the field 

 are a source of danger to sound stock since infection may be 

 carried on the knives used in cutting off the heads. This 

 may account for the common occurrence of the so-called 

 "stump rot" in cabbage in storage or transit. 



Slimy soft rot occurs commonly in southern winter-grown 

 bunch crops. It results from infection in the field, in transit 

 or in storage, and develops and spreads under any of these 

 conditions. It is favored by the moist atmosphere prevail- 

 ing in iced barrels, crates, and hampers in which these crops 

 are shipped, and in the cellars and pits in which northern 

 stock, especially cabbage and celery and the root crops, are 

 stored. High temperatures are of even greater importance, 

 however, and greatly accelerate the progress of this rot, 

 especially in potatoes. 



