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Key warning symptoms:

  • Mosaic

  • Veinbanding

  • Yellow spots, rings

  • Line pattern

  • Stem necrosis

The two viruses we most often detect in dahlias, Tomato spotted wilt and Impatiens necrotic spot viruses, are transmitted by thrips and by propagating infected plants. Tomato spotted wilt virus is more common in dahlias than impatiens necrotic spot virus. Both can cause many symptoms, including mosaic patterns on leaves, distorted leaves, stunted plants, dead stem sections, spots and ringspots.

Dahlia mosaic virus, transmitted by aphids, is also very common. It can cause stunting and yellow bands along leaf veins. Other symptoms, including mosaic and leaf distortion, can follow. Some varieties can be symptomless, or develop symptoms that later disappear.

Fungal Diseases - PCR

  • Alternaria alternata (Aalt) (Leaf spot)

  • Botrytis cinerea (Bcin) (Flower blight)

  • Rhizoctonia solani (Rsol) (Sterm/tuber rot)

  • Sclerotinia sclerotiorum (Sscl) (Cottony stem rot) 

  • Fusarium oxysporum (Foxy) (Vascular wilt)

  • Verticillum albo-atrum (Vaa) (Vascular wilt)


Dahlia Virus Screen

  • Cucumber mosaic virus (CMV) ELISA

  • Impatiens necrotic spot virus (INSV) ELISA

  • Potyvirus group test (Poty) PCR

  • Potato virus Y (PVY) ELISA

  • Tobacco streak virus (TSV) ELISA

  • Tomato spotted wilt virus (TSWV) ELISA

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