PEANUT DISEASES 295 



plants before the disease became visible. This would result in a reduced 

 number of nuts with many seedless pods (24) . Nuts, formed on rosetted 

 plants, were also noted as having a lower shelling percentage (27). 



It appears that at least two distinct types of symptoms, other than 

 the typical, have been recognized and called rosette, and subtypes or 

 variations of each in turn have been recognized and described. The fol- 

 lowing outline is based upon various published descriptions and the 

 summary of Weiss (158). 



VARIATIONS OF ROSETTE 



(A) Typical rosette (Storey and Bottomley (144)). 

 (See description above) 



(B) Chlorotic rosette 



Variation 1. Mosaic rosette: Mottling of leaves, no marked 

 yellowing. Less severe stunting or resetting (Storey and Bot- 

 tomley (144) and Hansford (56)). 



Variation 2. Yellows: More pronounced chlorosis, very pro- 

 nounced mosaic. No typical resetting (Hansford (56)). 



(C) Nonchlorotic rosette. 



Variation 3. Green rosette: Leaves darker green than normal. 

 No chlorosis (Hayes (59) and Porteres and Legleu (112)). 

 Variation 4. Clump rosette: Leaves normal green in color, 

 rosette condition more pronounced than typical or other 

 variations (Porteres and Legleu (112)). 



Of these variations the mosaic type and the clump type are infrequent 

 (56, 112), while typical rosette and yellows have been reported as having 

 the greatest effect upon yield (56). 



The Virus and pathogenicity. There are no indications that the virus 

 (or viruses) associated with rosette has been isolated or otherwise studied. 

 Weiss (158) recognized two acceptable technical names for the virus — 

 Arachis Virus 1 or Marmor arachidis. 



Peanut rosette has been transmitted by grafting (144) and by the 

 legume aphid (135, 143). Later reports noted that the disease could not 

 be transmitted to other legumes (141) nor could a rosette-type disease of 

 a wild plant in the Congo be transmitted to peanuts (135). Weiss, how- 

 ever, lists a butterfly pea, Centrosema plunieri Benth. as another host of 

 the virus (158). 



The legume aphid, Aphis leguniinosae Theob. is considered to be the 

 vector of peanut rosette virus (135, 143). Other insects, which have been 



