Other Country Site
General Conditions of Use
Privacy Statement
Imprint
2010 Bayer CropScience
Potato Pests & Diseases
Black Scurf
The fungus is visible on the tubers as black dots or dirt. Same pathogen can cause stem canker.
Stem Canker
Cankers growing on underground stems, leaving lesions on tubers.
Typical Damage:
Cankers can girdle stems and cause death of shoots. Same pathogen can cause black scurf.
Silver Scurf
Small light-brown spots on tuber surface. Under favourable storage conditions spots may become larger and merge. Spots darken as they grow older.
Typical Damage:
Small light-brown spots on tuber surface. Spots darken as they grow older.
Nematodes
Lesion nematodes are about 0,3 to 0,7 mm long and worm-like with all active adult and larval stages capable of entering the roots; thus there is no distinct infective stage as in Meloidogyne. Feeding takes place within the roots and eggs are deposited by the females within infected host plant tissue or in the soil. Female root-knot nematodes are round to pear-shaped, soft, white, less than 1 mm in diameter and sedentary within galls on the roots of infected plants. Unlike the female, the male root-knot nematode is worm-like, and mobile. The infective second-stage larva hatches from the egg and migrates to the host plant root which it penetrates. As the larva invades the root, feeding takes place until it reaches a suitable location, after which subsequent larval stages only feed on cells directly surrounding the head end.
Aphids
Small delicate pear-shaped insects with soft bodies and long legs and antennae. Usually greenish, with or without transparent wings.
Typical Damage:
Found in small colonies sucking sap of tender growth.
Millipedes
Long smooth round hardbodied many segmented “worms” varying in size from 1-20cm with two pairs of legs attached to each segment.
Typical Damage:Feeding damages the tubers.
Snails
Slugs
Greyish-brown slimy legless soft-bodied creature. Without coiled shell. Leaves a shiny trail of viscid secretion.
Typical Damage:
Feed on young succulent growth. Active only under damp conditions.

Snails
Shell is yellow-brown or white with brown markings, or mottled brown, about 20 or 35 cm in diameter when full-grown.
Typical Damage:
Feed mainly on leaves which are eaten away from the edges; sometimes also feen on young developing growth-points, resulting in malformed growth of the affected parts - characterised by shortened internodes and small blistered leaves.
Cutworms
Cutworm larvae are darkcoloured when small, becoming grey to brown when full-grown and up to 30 mm long. They adopt a characteristically curled-up attitude when removed from the soil. The adult moths have dull grayish forewings and pale whitish hind wings.
Typical Damage:
The larvae feed at ground level, often cutting completely through the stems of young plants. They feed at night and hide beneath the soil surface by day. Most damage is done in spring and early summer.
Black Maize Beetle
A shiny black beetle.
Typical Damage:
Eats holes in tubers. Larvae feed on dead organic matter in the soil.
Tuber Moth
Adult: Small greyish-brown moth with fringed hind wings.
Typical Damage:
Larvae: Feeds between upper and lower epidermis of leaves. Also tunnel into tubers making black tunnels filled with excreta.
Early Blight
Brown and black patches with concentric ring pattern on older leaves surrounded by yellowing of the leaf tissue.
Typical Damage:
Brown and black patches with concentric ring pattern on older leaves surrounded by yellowing of the leaf tissue.
Late Blight
Water-soaked or pale greenish spots on leaves that turn brown or almost black. A pale black border may be seen around lesions and sparse whitish growth on underside of leaf.
Typical Damage:
Leaves turn brown or almost black. Small greyish green water soaked areas on fruit that increase in size becoming dark brown and wrinkled.
Social Media
[ last update: Monday, April 2, 2012 ]