NAME OF THE ORGANISM: Pseudomonas syringae pv. lachrymans (PSDMLA)
GENERAL INFORMATION ON THE PEST
Name as submitted in the project specification (if different to the preferred name):
Pest category:
Bacteria
1- Identity of the pest/Level of taxonomic listing:
Is the organism clearly a single taxonomic entity and can it be adequately distinguished from other entities of the same rank?
Yes
Is the pest defined at the species level or lower?:
Yes
Can listing of the pest at a taxonomic level higher than species be supported by scientific reasons or can species be identified within the taxonomic rank which are the (main) pests of concern?
- Not relevant: Vegetable propagating and planting material (other than seeds) sector
Is it justified that the pest is listed at a taxonomic rank below species level?
Yes
Conclusion:
- Candidate: Vegetable propagating and planting material (other than seeds) sector
2 – Status in the EU:
Is this pest already a quarantine pest for the whole EU?
No
Presence in the EU:
Yes
Conclusion:
candidate
Justification (if necessary):
The pest is present in Bulgaria, Czechoslovakia, Denmark, France, Germany, Greece, Hungary, Italy, Netherlands, Poland, Romania and UK (CABI, 1987)
HOST PLANT N°1: Cucumis melo (CUMME) for the Vegetable propagating and planting material (other than seeds) sector.
Origin of the listing:
2 - Vegetable seedling sector: Commission Directive 93/61/EC
Plants for planting:
Plants intended for planting
3 - Is the pest already listed in a PM4 standard on the concerned host plant?
No
Conclusion:
Evaluation continues
4 - Are the listed plants for planting the main* pathway for the "pest/host/intended use" combination? (*: significant compared to others):
Yes
Conclusion:
Candidate
Justification:
Angular leaf spot is the most widespread bacterial disease of cucurbits (Compendium of Cucurbit Diseases, 1996). Natural hosts of the bacterium include Cucumis sativus, C. melo, C. melo var. indorus, C. anguria, C. dipsaceus, Citrullus lanatus, Cucurbita maxima, C. pepo var. melopepo, C. pepo var. medullosa, C. pepo var. condensa, Bryonopsis laciniosa, Lagenaria leucantha and Luffa acutangula (Bradbury, 1986). It is most serious in cucumbers grown in warms and humid conditions. Infection first appears on leaves, then infecting fruit and contaminating seed. The pathogen is seed-borne and infestation occurs beneath the seed coat so infecting the cotyledons and hence spreading to other plants. Therefore seed and young plants are a pathway. Control can consist of outside rotation for 2 years, cultivation when dry, copper sprays and resistant cvs. If these methods are effectively carried out (or being grown indoors), then young plants for planting can be considered the main pathway (Compendium of Cucurbit Diseases, 1996).
5 - Economic impact:
Are there documented reports of any economic impact on the host?
Yes
Justification:
It is a serious pathogen of cucurbits, causing cosmetic damage to skin, disfiguring fruit and causing a fruit rot (Compendium of Cucurbit Diseases, 1996).
What is the likely economic impact of the pest irrespective of its infestation source in the absence of phytosanitary measures? (= official measures)
Minor
Is the economic impact due to the presence of the pest on the named host plant for planting, acceptable to the propagation and end user sectors concerned?
Yes
Is there unacceptable economic impact caused to other hosts (or the same host with a different intended use) produced at the same place of production due to the transfer of the pest from the named host plant for planting?
No
Conclusion:
Not candidate
Justification:
Economic impact is considered minor, compared to cucumber and squash.
CONCLUSION ON THE STATUS:
Disqualified: impact is acceptable on this host plant. The 'substantially free from' requirement is a sufficient risk management measure.
8 - Tolerance level:
Is there a need to change the Tolerance level:
No
Proposed Tolerance levels:
Delisting.
9 - Risk management measures:
Is there a need to change the Risk management measure:
No
Proposed Risk management measure:
Delisting.
REFERENCES:
- CABI (1987) Distribution map for Pseudomonas syringae pv. lachrymans (E.F. Smith & Bryan) Young, Dye & Wilkie. Distribution Maps of Plant Diseases. Map No. 355 (Edition 4);
- Compendium of Cucurbit Diseases (1996) First edition. The American Phytopathological Society;