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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Vegetable > Potato > Leaves yellow and wilt

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Potato > Leaves > Leaves yellow and wilt

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  • Verticillium Wilt 1
  • Verticillium Wilt 2
  • Verticillium Wilt 3

Verticillium Wilt
Verticillium spp.

  • Leaves turn yellow then brown and wilted, stems remain erect
  • Symptoms are often seen on one or a few stems but not the entire plant
  • Often only random plants scattered in the field are affected
  • If the stem is cut near the soil line, brown streaks or rings can be seen just under the skin
  • Dark brown to black streaks or rings can be seen in the tuber flesh if cut on the stem end
  • More information on Verticillium Wilt
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  • Potato Aphid and Green Peach Aphid 1
  • Potato Aphid and Green Peach Aphid 2

Potato Aphid and Green Peach Aphid
Macrosiphum euphorbiae and Myzus persicae

  • Feeding by small or moderate numbers of aphids usually does not cause visible symptoms
  • Feeding by larger numbers of aphids can cause curling, stunting, and wilting of leaves
  • Active during spring and summer
  • 1/10th inch long
  • Small insects, pear-shaped, usually greenish; clustered on underside of leaves
  • More information on Potato Aphid and Green Peach Aphid
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  • White Mold 1

White Mold
Sclerotinia sclerotiorum

  • Leaves wilt but remain green
  • Elongated tan dry lesions form on stems
  • Fluffy white fungal growth and small hard black fungal sclerotia can be found on or in infected stems
  • More information on White Mold
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  • Black Dot 1
  • Black Dot 2
  • Black Dot 3

Black Dot
Colletotrichum coccodes

  • Leaves may have random brown spots, or may yellow and wilt due to infection of stem and roots
  • Irregular patches of gray discoloration on surface of the potato tuber
  • Sunken dark brown to black lesion on stem that turns white in the center with age
  • Many pinprick sized black dots can be seen on infected stems and tubers (handlens is helpful)
  • More information on Black Dot
5 of 6
  • Blackleg and Soft Rot 1

Blackleg and Soft Rot
Pectobacterium carotovora

  • In severe cases, plant is stunted, with yellow and wilted leaves
  • Seed potato may rot in the soil, plants do not emerge
  • Brown to black slimy sunken lesions on stems, most common starting at the soil line
  • Tuber flesh is white, soft and rotted. In severe cases the entire tuber rots away, leaving on the skin
  • Favored by cool wet weather
  • More information on Blackleg and Soft Rot
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  • Zebra Chip 1
  • Zebra Chip 2
  • Zebra Chip 3

Zebra Chip
Candidatus Liberibacter spp.

  • Aerial tubers form from main stem
  • Leaves may be purple or yellow, appear scorched, and wilt
  • Inside of potato is a mottled brown
  • Vectored by the potato psyllid
  • Currently not found in MN. If suspected, report it to the Minnesota Department of Agriculture at the "Arrest the Pest" Hotline: 651-201-6684 (metro) or 1-800-545-6684 (Greater Minnesota)
  • More information on Zebra Chip

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