other states than north. When the plants are first affected, they turn 

 a pale yellow and in a few days they are dead. Prof. Warsham made 

 a systematic study of the disease. Mr. A. C. Lewis has issued a bulle- 

 tin giving the results of the Professor's investigations that seems so 

 comprehensive and valuable that we take the liberty to reproduce 

 some of the statements made by him. 



"The first outward symtoms of black root is generally a wilting of 

 some of the leaves. Many of the young plants die within a few days 

 after the symptoms of the disease appear, which is usually when they 

 are about six weeks old. Plants will continue to die now and then 

 until frost. Some of the plants attacked may partially recover from 

 the disease, and put out side branches near the ground, but as a rule 

 these branches do not produce much cotton. In the course of time 

 plants killed by the black root disease lose all their leaves, and the 

 small branches drop off leaving only the blackened stem standing. 

 Many plants that are not killed outright by the disease are much 

 stunted in growth and their yield reduced. This phase of the disease 

 is often overlooked by many planters. In several instances nearly 

 whole fields have been found in this stunted condition and the owner 

 was not even aware that the cotton was diseased. 



"The internal symptoms of the disease are very characteristic, so 

 that it is not difficult to tell black root from any other disease that cotton 

 is subjected to in Georgia. If the roots and stem of a diseased plant 

 are examined by cutting lengthwise, it will be found that the woody 

 portions are black or much discolored. This is the symptom that 

 has given the disease the name 'black root.* 



"The cause of the cotton disease commonly called 'black root' or 

 'wilt' is a fungus, which attacks the roots and stem of the plants. Dur- 

 ing the winter the fungus lives on the decaying cotton roots and stems 

 and in the soil mainly in the form of spores. (The spores correspond- 

 ing to the seeds of the higher plants.) In the spring when the cotton 

 begins to form rootlets and roots these are attacked by the fungus. 

 The fungus penetrates the roots and grows up into the stem following 

 the water ducts and plugging them with its mydelium. This prevents 

 the upward flow of sap from the roots, thus cutting off the food supply 

 and stunting or killing the plants. 



"Some seasons the black root disease is worse than in other seasons. 

 This may be due to one or two causes, the weather conditions or the 

 number of nematodes in the soil. Thus it has been observed that 

 the disease is more severe during a wet season than a dry one. Fre- 

 quently we have received letters from cotton growers stating that 

 in a few days after the last rain, much of their cotton wilted and died. 

 They wanted to know the reason for this, not suspecting before the 

 rain that the cotton was diseased. While it is true that wet weather is 



