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Seedling Pests—Planting

On this page
  • Damping off
  • Downy mildew
  • Sclerotinia rot
  • Sclerotinia rot
  • Stem nematode
  • Cutworms
  • Aphids

Keep records of pests you see to help choose a seedling variety for next year’s alfalfa planting and to implement proper equipment sanitation. Names link to more information on identification and management.

Click on photos to enlarge
Photo of damping off disease
Damping off diseases
Identification tip: Roots and leaves rot due to seedling diseases (damping off).
Leaves infected with Downy mildew
Downy mildew
Identification tip: Spots on upper sides of infected leaves are gray-green to tan.
Sclerotinia rot
Sclerotinia rot
Identification tip: Hard black sclerotia resting bodies form on the mat of white mycelium.
Plant infected with stem nematodes
Stem nematode
Identification tip
: Plants infected with stem nematodes have dead stem buds, stunted shoots, and swollen internodes.

Cutworm damage
Identification tip: Caterpillars are about 1.5 to 2 inches long and appear smooth-skinned with various colors and patterns. Larvae frequently roll into a C shape when disturbed.

Identification tip: Four aphids commonly cause damage in alfalfa hay. To identify cowpea aphid, pea aphid, blue alfalfa aphid and spotted alfalfa aphid, see “Identifying aphids”.

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Statewide IPM Program, Agriculture and Natural Resources, University of California
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Agriculture and Natural Resources, University of California

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