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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Vegetable > Asparagus > Spots on spear

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Asparagus > Spear > Spots on spear

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  • Image: Aphid 1
  • Image: Aphid 2
  • Image: Aphid 3

Purple Spot
Stemphylium vesicarium

  • Small purple sunken ovals on spears or ferns
  • Spots grow larger with a purple border and a brown center
  • Severe infection of the fern can result in premature defoliation and dieback
  • Common on exposed sandy sites
  • More information on Purple Spot...
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  • Image: Aphid 1
  • Image: Aphid 2

Cercospora Leaf Spot
Cercospora asparagi

  • Oval lesions with tan or gray center and reddish brown border
  • Lower portion of ferns turn brown, eventually moving up plant
  • Entire fern may turn yellow and die by mid season
  • Disease often most severe when plants are big enough to crowd one another
  • More information on Cercospora Leaf Spot...
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  • Image: Fusarium Wilt 1
  • Image: Fusarium Wilt 2
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Phytophthora Crown and Spear Rot
Phytophthora megasperma

  • Spear has a soft dark water soaked lesion at the soil line
  • Spear curls over the infected side and eventually collapses
  • Infected part of spear is slimy and may smell bad
  • Roots have water soaked spots
  • Crown turns yellow
  • In severe infections plant may die
  • More information on Phytophthora Crown and Spear Rot...

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