Plant Disease (2015) 99, 1808-1815

T.B. Enzenbacher, R.P. Naegele and M.K. Hausbeck (2015)
Susceptibility of greenhouse ornamentals to Phytophthora capsici and P. tropicalis
Plant Disease 99 (12), 1808-1815
Abstract: The susceptibility of fabaceous (Lupinus and Lathyrus spp.) and solanaceous (Calibrachoa, Browallia, Nicotiana, Nierembergia, and Petunia spp.) ornamental plants compared with straightneck squash (Cucurbita pepo) inoculated with Phytophthora capsici and P. tropicalis was investigated in greenhouse studies. Four P. capsici isolates and one P. tropicalis isolate were evaluated. Flowering tobacco (Nicotiana × sanderae), sweet pea (Lathyrus latifolius), lupine (Lupinus polyphyllus), squash, and million bells (Calibrachoa × hybrida) were susceptible to P. capsici and P. tropicalis. Bush violet (Browallia speciosa) and cup flower (Nierembergia scoparia) were not susceptible to either pathogen. Petunia (Petunia × hybrida) was susceptible to P. capsici but not P. tropicalis. Area under the plant growth curve (AUPGC) was also affected in some susceptible plants. AUPGC was significantly different in inoculated plants compared with the untreated controls of Nicotiana and Calibrachoa. In addition, six Calibrachoa cultivars were evaluated for susceptibility to P. capsici and P. tropicalis in a separate experiment. Although all Calibrachoa cultivars were susceptible to P. capsici and P. tropicalis, 'Celebration Purple Star' displayed limited disease following inoculation with either pathogen. Calibrachoa 'Cabaret' and 'Can-Can' inoculated with P. capsici or P. tropicalis displayed significant differences in AUPGC compared with the uninoculated controls. 'Callie', 'Million Bells Cherry Pink', and 'Superbells' had significantly reduced AUPGC compared with the controls when inoculated with P. tropicalis but not P. capsici. These results expand the host range of P. capsici to include Calibrachoa spp., L. polyphyllus, and Lathyrus latifolius, and P. tropicalis to include L. latifolius, Nicotiana spp., and straightneck squash.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Mary K. Hausbeck

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Phytophthora capsici	Lupin (Lupinus)
	Phytophthora capsici	Squash/pumpkin (Cucurbita)
	Phytophthora capsici	Vetchling (Lathyrus)
	Phytophthora capsici	Petunia (crop)
	Phytophthora tropicalis	Lupin (Lupinus)
	Phytophthora tropicalis	Squash/pumpkin (Cucurbita)
	Phytophthora tropicalis	Vetchling (Lathyrus)