Causal Agent

The fungus Rhizoctonia solani 

 

Hosts

Peanuts 

 

Symptoms

Limb rot usually appears in late August and September after the vines of runner varieties have lapped. Elongated spots (lesions) develop on the underside of lower branches in contact with the soil. The lesions are dark brown and may have a target-like appearance. Lesions expand and girdle individual branches causing them to wilt and die. Several branches may be killed, but generally not entire plants as with Sclerotinia and southern blights. In severe cases where rainfall is excessive, leaves within the canopy are covered with a white, moldy growth. In addition to causing pod rot, the fungus also may infect the tips of pegs as they penetrate the soil. The pod-forming region of infected pegs is killed, turns black, and appears shredded.

 

Control

Please contact your local county extension office for current information.