288 THE PEANUT— THE UNPREDICTABLE LEGUME 



and below these moistures, concealed damage develops slowly, with little 

 development below 10 percent. There seems to be no relationship between 

 soil type or fertilizer practices and development of concealed damage. 

 It may be more prevalent, however, when fields are cropped continuously 

 to peanuts. 



Control. Moisture content being closely related to development of 

 concealed damage, control measures are centered in attempts at rapid 

 drying of seeds. Since artificial curing with dry air is still in the experi- 

 mental stage, control of concealed damage at present is dependent upon 

 some variation of field curing that hastens the removal of moisture. 



The safest method of field curing peanuts is stacking rather than 

 windrowing or piling in "cocks" (166). Preliminary studies in Florida 

 (21) have shown no relation between method of stacking and concealed 

 damage, but similar studies in Georgia (52) have indicated that signifi- 

 cantly less concealed damage develops when plants are stacked wilted 

 (not brittle) than that which develops when plants are stacked "green" 

 or unwilted. 



BLUE DAMAGE" 



Importance. Spanish peanuts reaching the market are frequently 

 graded down because of a prominent blue-black discoloration of many 

 seeds. In some years this discoloration is not troublesome, but in other 

 years peanut shellers have reported losses up to 25 percent from this 

 disease. Sometimes entire lots are rejected by peanut brokers because of 

 this discoloration. 



Description. Usually when blue damage is found in a seed lot, a large 

 proportion of the seeds is conspicuously affected, though sometimes only 

 very few seeds are damaged. The discoloration may occur in such an 

 inconspicuous form and on so few seeds that it is easily overlooked. 



This discoloration varies through several shades of blue-black. One 

 spot may be of several shades, or different spots on the same seed may be 

 of dififerent shades. Sometimes the discoloration is a streak following 

 either veins of the seed coat or the suture between cotyledons. The spots 

 vary in size. The smallest are about 2 mm. in size and of a distinct "bull's 

 eye" type with centers bleached, slightly darker, or the natural color of 

 the seed coat. Larger spots are irregular in shape with no evident center. 

 All possible variations can be found in a single lot of discolored seeds. 



Spanish peanut lots containing blue-damaged seeds generally have 



'"This section is a condensation of the report by Garren, Higgins and Futral (49), the only 

 published work on this disease to date. 



