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Key warning symptoms:

  • Spots, ringspots

  • Mosaic

  • Wilt

  • Chlorosis

  • Necrotic spotting

The most economically destructive disease of geraniums is bacterial blight, caused by Xanthomonas hortorumpv. pelargonii(Xhp). Symptoms can include small water-soaked or brown spots on the undersides of leaves, yellowed wedge-shaped areas on leaves, and black, collapsed stems. Xhp most often occurs in plants grown from infected cuttings, but can be spread to healthy plants by water splashing of contaminated soil, insects, dirty hands, or contaminated tools. Hanging baskets of ivy geraniums infected with Xhpcan transmit the bacteria by water splash to other geraniums grown under or near them.

We have multiple Xhp tests, each has a different speed, sensititivity, and application to fit different needs. Our specific ELISA test requires less than 24 hours. If the result is positive, we report it immediately. We can confirm the results using other tests, a polymerase chain reaction test (PCR), bio-assay, and by a culture-enhanced assay, or each of these tests can also be used by itself.

Tobacco ringspot virus, Tomato ringspot virus, Pelargonium ringspot, or a combination of any of the three produce symptoms in geranium which include, yellow or dead spots, rings and line patterns on leaves, fewer flowers and aborted buds. virus. Tomato ringspot and Tobacco ringspot viruses can be spread by soil-borne nematodes, cuttings, and seed. Pelargonium ringspot virus can be spread mechanically and by soil. 

Fungal Diseases - PCR

  • Alternaria alternata (Aalt) (Leaf spot)

  • Botrytis cinerea (Bcin) (Botrytis blight)

  • Fusarium spp (Fus) (Fusarium cutting rot)

  • Phytophthora spp (Phyt) (Root rot)

  • Pythium spp (Pyth) (Damping-off/root rot)

  • Rhizoctonia solani(Rsol) (Root/crown rot)

  • Selerotinia sclerotiorum(Sscl) (Stem rot)

  • Verticillium albo-atrum(Vaa) (Verticillium wilt)

  • Verticillium dahlia(Vda) (Verticillium wilt)


Bacterial Diseases

  • Acidovorax avenae subsp. citrulli (Aac) (Leaf spot) ELISA 

  • Agrobacterium tumefaciens (Crown gall) PCR

  • Pseudomona (Pseu) (Leaf spot) PCR

  • Pseudomonas syringae (Psyr) (Leaf spot) PCR

  • Ralstonia (Pseudomonas) solanacearum (Rs) (Southern wilt) PCR

  • Xanthomonas campestris (Xc) (Bacterial blight)  PCR

  • Xanthomonas hortorumpv. pelargonii (Xhp) (Bacterial blight) ELISA


Geranium Virus Screen - ELISA

  • Cucumber mosaic virus (CMV)

  • Impatiens necrotic spot virus (INSV)

  • Pelargonium flower break virus (PFBV)

  • Tobacco mosaic virus (TMV)

  • Tobacco ringspot virus (TRSV)

  • Tomato ringspot virus (ToRSV)

  • Tomato spotted wilt virus (TSWV)


Other virus tests available for geranium

  • Carlavirus group test (CarLa) PCR

  • Impatiens necrotic spot virus (INSV) ELISA

  • Nepovirus group test (Nepo) PCR

  • Pelargonium leaf curl virus (PLCV) ELISA

  • Pelargonium zonate spot virus (PZSV) ELISA

  • Potyvirus group test (Poty) PCR

  • Tobamovirus group test (Tobamo) PCR

  • Tomato spotted wilt virus (TSMV) ELISA

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