23 



Diseases of Peanuts. 



Leaf spot, wliicli appears as a small, brown spot on 

 the leaves and stems (See spots on leaves of Wiiile 

 Spanish variety, PI. I, Fig. 2), is caused by a iungus dis- 

 ease (Cercosjwra pevsonata). It usually attacks the 

 grown leaves, though it may attack the young ones, 

 causing them to fall oil", thereby reducing the vahie of 

 the hay and the yield of peanuts. 



This leaf spot fungus may be carried from one year 

 to the next on old peanut leaves and stems. Crop 

 rotation and plowing under all old vines and stems 

 are, therefore, recommended as good farm practice 

 to lessen the amount of the disease in a succeeding 

 peanut crop. ' 



Sclerotial rot, (caused by Sclerotiiim Rolfsii) attacks 

 the roots and peas, and destroys the pods. The top 

 of the plant may be healthy in appearance, but when 

 it is pulled up, many of its pods may be found com- 

 pletely rotten. The rotten pods may appear wet or 

 drv, as other organisms of decay may have become 

 associated with the decayed nuts. 



No means of combatting sclerotial rot is known. 



Red rot attacks the pods of the peanut and causes 

 them to appear brown or reddish. The crop should 

 be dug as soon as it matures to avoid loss from this 

 disease. (See Alabama Station Bulletin No. 180). 



Average Yield of Peanuts. 



According to figures furnished by the Bureau of 

 Crop Estimates of the United States Department of 

 Agriculture, the average yield of peanuts for the 

 United States for the past five years has been 38. 6 

 bushels per acre. For the same period, the Southern 

 States averaged as follows: 



State Bushels State Bushels 



Nortli Carolina 42 Alaljama 37 



South Carolina 45 Louisiana 32 



Georgia 40 ]\Ii.ssissippi 34 



Florida 36 Texas . 33 



Tennessee 48 Oklahoma 38 



As a rule, the yield is very nearly in proportion to 

 the thickness of the stand. Especially is this true with 

 the Spanish varieties. The largest yield on record is 

 one made on the farm of Dr. J. F. Yarbrough, at Colum- 

 bia, Alabama. The yield, as reported by Dr. Yar- 

 brough, on the basis of 24 pounds of Spanish peanuts- 



