VII 



PEA PEANUT 231 



vagum, B. & G., var. solani, Burt. At least one of 

 these is known to occur on other plants in the tropics, 

 and may be reported at any time. 



Root Rot. A variety of Necosmospora vasinfecta, 

 Smith, attacks the cow-pea in tropical and semi-tropical 

 America. Its behaviour is practically the same as the 

 related variety on cotton (page 108), melons, and okra. 



PEANUT 



Very little has been written concerning the diseases 

 of this very important crop. 



Rust. A disease due to the rust fungus Uredo 

 arachidis, Lagh., has been reported from St. Vincent, 

 Dominica, Montserrat, St. Kitts, Cuba, and the Carolinas. 

 It causes minute brown or yellow pustules on the under 

 surface of the leaves, and to some extent on the petioles. 

 As a rule it does not appear until the plants are almost 

 mature, and is frequently confined to the older leaves. 

 The fungus is known only in the uredo stage. 



This disease is generally considered of very little 

 importance, although there have been some rather 

 severe outbreaks which injured the foliage and interfered 

 with the maturing of the nuts. Wherever this disease 

 is threatening, it would be well to clean the field 

 thoroughly and burn the old vines. Small plantings 

 can be protected in a great measure by the use of 

 Bordeaux mixture, but it is doubtful if this would be 

 practical on large plantings. 



Leaf Spot. The most important leaf-spot disease 

 is due to Cercospora personata, Ellis, 1 which causes 

 rather large, black, circular spots on the leaves, and is 

 also said to attack the very young fruits and to inter- 

 fere with their development. It has been reported 

 as very injurious in the United States, Porto Kico, 

 and Dominica. 



Septogloeum arachidis, Kacid, is a fungus which 



1 Cladosporium personatum, Berk. & Curt. 



