270 THE PEANUT— THE UNPREDICTABLE LEGUME 



Table 2. — Fungi Isolated from Peanuts with Collar Rot in Georgia, 1945-1947^ 



Fungus isolated 



Fusarium spp 



Diplodia sp 



Pemcillium spp 



Aspergillus spp 



Rhizopus sp 



Sclerotium bataticola 



Rhizoctonia solani 



Trichoderma spp 



Bacteria 



Comparative frequency 



Frequent 



Frequent 



Fairly frequent 



Fairly frequent 



Fairly frequent 



Fairly frequent 



Rare 



Rare 



Rare 



living only when some adventitious roots have developed. In this stage, 

 the main axis and taproot are shredded and held together by a few sound 

 vascular bundles. The mass of dead tissue is usually dark reddish brown 

 and powdery. 



Organisms and pathogenicity. The nature of early collar rot suggests 

 a fungous disease, and no evidence has been obtained which would con- 

 nect insects or grubs directly with the disease. Somewhat detailed isola- 

 tions of fungi from diseased plants have been made, and typically, a 

 variety of fungi was isolated with no agreement between seasons as to the 

 predominant fungus. Table 2 lists the comparative frequency of isolation 

 of several fungi from diseased plants in Georgia. 



Similar results have been reported from North Carolina (101, 111). 



Since a number of these fungi have been reported as pathogens on pea- 

 nuts (table 3), inoculation tests were run for 3 years at the Georgia Ex- 



Table 3.- 



-FuNGi Ordinarily Considered Saprophytes Reported as Pathogenic 

 FOR Peanuts 



' Unpublished data, Georgia Experiment Station. 



