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Caption: Narcissus nematode damage
Photo by: R.S. Byther
  
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Narcissus (Daffodil) : Stem and bulb nematode
(revision date: 4/23/2014)


Biology
Nematodes are tiny (often microscopic), parasitic worms that live in the soil and in infected plant parts. The stem and bulb nematode of narcissus feeds mainly on aboveground portions of the plant. The initial symptom is the presence of small swellings or "spikkels" on the leaves. Foliage is distorted and turns yellow or brown in affected areas. Flowers may be delayed or absent. The nematodes may move into the bulb, causing brownish areas in the bulb tissue and sometimes causing softening or rotting of stored bulbs. Plantings infested with nematodes often show circular areas of stunted or prematurely yellow plants. These patches expand gradually.
Management Options

Non-Chemical Management
  • Remove and destroy infected plants and bulbs.
  • Prevent contamination with infested soil. Clean equipment and tools before moving from infested to clean areas.
  • Plant only firm, healthy bulbs.
  • Clean up and destroy dead foliage.
  • Hot-water treatment of bulbs (4 hours at 111 degrees F) will kill nematodes, but may increase disease problems (especially basal rot) if diseased bulbs are dipped. This treatment can also result in flower and leaf distortion in the season after treatment.
Select non-chemical management options as your first choice!

Chemical Management


None recommended

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Caption: Narcissus nematode damage
Photo by: R.S. Byther
Caption: Narcissus nematode damage
Photo by: R.S. Byther
Caption: Narcissus nematode damage on leaves
Photo by: R.S. Byther