Peanut Diseases
From BugwoodWiki
Contents |
White Mold (fungus Sclerotium rolfsii)
White mold results in a brown dry rot of the lower stem and crown and one or more branches wilt and die. Up to 10 to 12 adjacent plants may wilt and show signs of the disease. The stems of diseased plants and often the ground and lower leaves are covered with a dense, white fungus growth. Small, brown fungus fruiting bodies similar to mustard seed usually form on dead stems and leaves.
  Photo by Clemson University - USDA Cooperative Extension Slide Series, , Bugwood.org |  Photo by Division of Plant Industry Archive, Florida Department of Agriculture and Consumer Services, Bugwood.org |
Peanut Leaf Spots
These include:
- early leaf spot, fungi Cercospora arachidicola
- late leaf spot, Cercosporidiuum personatum
The first symptoms of both diseases are small, pale yellow or blanched spots. These soon enlarge and become tan to black. The color of the spot on the lower leaf surface can often be used to distinguish between early and late leaf spots. Early leaf spot is brown and late leaf spot is black.
 Photo by Department of Plant Pathology Archive, North Carolina State University, Bugwood.org |
Pod Rots
These may include:
- fungi Rhizoctonia solani
- Pythium myriotylum
- Fusarium solani
- occasionally other fungi.
Pods show varying degrees of discoloration, from slight superficial brown and black spots to complete pod discoloration. Partial or complete rotting of pods and kernels may occur. This may be a dry rot to a mushy, wet rot. Pods are often left in the ground at digging.
 Photo by Clemson University - USDA Cooperative Extension Slide Series, , Bugwood.org |
Nematodes (root-knot Meloidogyne arenaria, M. hapla)
Above-ground symptoms are yellowing, wilting and stunting of plants in areas from a few feet in diameter to several acres. Roots usually have knots and galls that vary in size from slight swelling to large galls 3 or 4 times the size of the root. Pegs and pods are usually distorted with galls.
 Photo by Jonathan D. Eisenback, Virginia Polytechnic Institute and State University, Bugwood.org |
