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Dahlia

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Dahlia

Dahlia
Genus:Dahlia
Family:Asteraceae
Type:Tender perennials
Pollination:Insect

Dahlia is a genus of bushy, summer- and autumn-flowering, tuberous perennials that are originally from Mexico, where they are the national flower.

Description

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In 1872 a box of Dahlia roots were sent from Mexico to the Netherlands. Only one plant survived the trip, but produced spectacular red flowers with pointed petals. Nurserymen bred from this plant, which was named Dahlia juarezii with parents of Dahlias discovered earlier and these are the progenitors of all modern Dahlia hybrids. Ever since, plant breeders have been actively breeding Dahlias to produce thousands of cultivars, usually chosen for their stunning and brightly coloured flowers. Dahlia plants range in height from as low as 12" (30 cm) to as tall as 6–8 feet (180–240 cm). The flowers can be as small as 2" (5 cm) or up to a foot (30 cm) in diameter. The great variety results from Dahlias being octoploids (they have eight sets of homologous chromosomes, whereas most plants have only two).

Growing conditions

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Varieties

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Uses

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Maintenance

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Propagation

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Harvesting

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Pests and diseases

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Dahlias are used as food plants by the larvae of some Lepidoptera species including Angle Shades, Common Swift, Ghost Moth and Large Yellow Underwing. Crown Gall

  • Agrobacterium tumeifasciens

Wilt

  • Pseudomonas solanacearum

Rot (Bacteriosis)

  • Erwinnia carotovora

Powdery Mildew

  • Erysiphe cichoracearum
  • Erysiphe polygoni

Leaf Spots

Gray Mold

Blight

  • Botrytis cinerea

Wilts

  • Fusarium
  • Verticillium albo-atrum

Stem Rots

  • Pellicularia filamentosa
  • Pellicularia rolfsii
  • Pythium debaryanum
  • Pythium oedochilum
  • Pythium ultimum
  • Sclerotinia sclerotiorum

Soft Rots

Smuts

  • Entyloma dahliae: Dahlia Smut

Viruses

  • Impatiens Necrotic Spot Virus
  • Tomato Spotted Wilt Virus
  • Cucumber Mosaic Virus
  • Dahlia Mosaic Virus

Nematodes

  • Meliodgyne haple
  • Meliodgyne incognita
  • Potato Rot Nematode: Ditylenchus destructor:

Aphids

Hoppers

Mealybugs

Whiteflies

Bugs

Earwigs

Thrips

Beetles

Caterpillars

Wasps

Mites

Slugs

References

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Wikimedia Commons has media related to: Dahlia

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