Legend
Justification for qualification based on EPPO PM 4 Standards
Justification for disqualification
Additional or non-conclusive information
Standard text

back...

NAME OF THE ORGANISM: Pseudomonas syringae pv. syringae (PSDMSY)

GENERAL INFORMATION ON THE PEST

Name as submitted in the project specification (if different):

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: Fruits (including hops) sector

If necessary, please list the species:

Is it justified that the pest is listed at a taxonomic rank below species level?

Yes

Conclusion:

Candidate: Fruits (including hops) sector

Justification (if necessary):

It was considered that listing at pathovar level was justified because of importance of host specialization within Pseudomonas syringae
Pseudomonas syringae pv
- actinidiae – infects kiwi (plant test)
- lachrymans – infects Cucurbitaceae (seed test)
- maculicola – infects radish and cabbage (seed test)
- syringae – infects bean (seed test), diagnostics apple
- pisi – infects peas (seed test)
- porri – infects leek & chives (Allium) (seed test)
- tomato – infects tomato (seed test)
- etc.

2 – Status in the EU:

Is this pest already a quarantine pest for the whole EU?

Presence in the EU:

Yes

List of countries (EPPO Global Database):

Conclusion:

Candidate

Justification (if necessary):

P. syringae pv. syringae is widespread from tropical areas to northern Europe and Canada, Australia and New Zealand. It has been reported in the EU in Austria (present - CABI/EPPO, 2012), Belgium (present – Bradbury, 1986), Bulgaria (present - CAB International, 1988), Cyprus (present - Bradbury, 1986), Denmark (present - Bradbury, 1986), France (present - Bradbury, 1986), Germany (present - Bradbury, 1986), Greece (present - Bradbury, 1986), Hungary (present - Bradbury, 1986), Ireland (present - CAB International, 1988), Italy (present - CABI/EPPO, 2012), Latvia (present - CABI/EPPO, 2012), Lithuania (present - CABI/EPPO, 2012), Netherlands (present - Bradbury, 1986), Poland (present – Bradbury, 1986), Portugal (present - Bradbury, 1986), Romania (present - Bradbury, 986), Slovenia (present - Dreo et al. , 2004), Spain (present - CABI/EPPO, 2012), Sweden (present - Bradbury, 1986). Cited from CABI crop protection compendium (https://www.cabidigitallibrary.org/doi/abs/10.1079/cabicompendium.45010).

HOST PLANT N°1: Cydonia oblonga (CYDOB) for the Fruits (including hops) sector.

Origin of the listing:

Commission Implementing Directive (EU) 2014/98/EU and Commission Implementing Regulation (EU) 2019/2072

Plants for planting:

Plants intended for planting

3 - Is the pest already listed in a PM4 standard on the concerned host plant?

Conclusion:

Evaluation continues

Justification (if necessary):

Inspection for 'Pseudomonas spp.' recommended in EPPO Standard PM 4-27 Pathogen-tested material of Malus, Pyrus and Cydonia. In responses to the questionnaire, DE, FR and SI supported deregulation (or revise threshold for FR). DE highlighted the unclear taxonomy making laboratory analysis difficult and the widespread presence of the bacteria as an epiphyte on plants. Evaluation continues applying full methodology.

4 - Are the listed plants for planting the main* pathway for the "pest/host/intended use" combination? (*: significant compared to others):

Conclusion:

Not candidate

Justification:

P. syringae pv. syringae is found in soil and water and on plant surfaces worldwide. It is transmitted and disseminated through living plants and vegetative propagation material (CABI, 2020). Pseudomonas syringae can be isolated from apparently healthy plants without disease symptoms being evident for several years, indicating either an epiphytic phase (epiphytic member of the phyllosphere of healthy plants) or the presence of latent infections (Agrios, 2005; CABI, 2020). It is spread by wind driven rain, rain splash, windblown rain, direct contact with the host, insects such as flies and bees, and hands, handling of plants and tools, and movement of infected nursery stock. Under favorable conditions, the bacteria enters the plant through wounds or natural openings such as stomata, and multiply rapidly within the apoplast. Water soaking of tissues during heavy rains greatly favors penetration and invasion. Bacteria multiplies on the walls of host cells, which collapse after disruption of the cell membranes (Agrios, 2005).
Plants for planting can be a pathway for Pseudomonas syringae pv. syringae, however due to its extensive distribution in the EU and its ease of natural spread, plants for planting are not considered to be a significant pathway compared to others. The Fruit SEWG considered that most orchards or their surrounding are already infested with this pest (CABI, 2020; HORTIPENDIUM, 2013).

5 - Economic impact:

Are there documented reports of any economic impact on the host?

Yes

Justification:

Cydonia is mentioned as host, but with no specific information on impact. Chiriac et al. (2014) indicated that the reaction on Cydonia sp. in invitro material was comparable to the reaction of pear. Quince is used as a rootstock for pear and might therefore be less important for a pathogen which enters via blossom and leaf buds. Quince is also commercially grown for fruits in certain areas, however the pathogenicity may be comparable with possible infections of E. amylovora on pear (Anonymous, 2024).

What is the likely economic impact of the pest irrespective of its infestation source in the absence of phytosanitary measures? (= official measures)

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?

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?

Conclusion:

Justification:

Remark: Wet weather, high relative humidity, and relatively cool (15-25°C) spring temperatures favors disease development (CABI, 2020). The economic impact is difficult to quantify because it depends on the intensity of the epidemic. There may be a transfer to another host in the vicinity (pears, apples etc.)

6 - Are there feasible and effective measures available to prevent the presence of the pest on the plants for planting at an incidence above a certain threshold (including zero) to avoid an unacceptable economic impact as regards the relevant host plants?

Conclusion:

Justification:

Appropriate growing practices (e.g. fungicide treatment of plants for planting, agricultural practice, irrigation, no overfertilization), use of certified/controlled CAC material, inspections at appropriate vegetation stages etc.

7- Is the quality of the data sufficient to recommend the pest to be listed as a RNQP?

Conclusion:

Justification:

CONCLUSION ON THE STATUS:

Disqualified: plants for planting is not a significant pathway and lack of data on economic impact

8 - Tolerance level:

Is there a need to change the Tolerance level:

Yes

Proposed Tolerance levels:

Delisting

9 - Risk management measures:

Is there a need to change the Risk management measure:

Yes

Proposed Risk management measure:

Delisting

REFERENCES:

Agrios GN (2005). Plant Pathology, 5th Edition. Elsevier Academic Press. 922 pp.
Bradbury JF, 1986. Guide to Plant Pathogenic Bacteria. Wallingford, UK: CAB International.
CABI/EPPO (2012). Pseudomonas syringae pv. syringae. [Distribution map]. Distribution Maps of Plant Diseases, No. October. Wallingford, UK: CABI, Map 336 (Edition 5).
CABI (2020) CPC Crop protection compendium: Pseudomonas syringae pv. syringae (bacterial canker or blast (stone and pome fruits)). 08042024. https://www.cabidigitallibrary.org/doi/abs/10.1079/cabicompendium.45010
Chiriac IP, Lipşa FlD& Ulea E (2014) Comparative study regarding in vitro infections with Erwinia amylovora and Pseudomonas syringae pv. syringae on pomaceae species. Cercetări Agronomice în Moldova XLVIII No. 1 (161) / 2015
Dreo T, Seljak G, Demšar T, Ravnikar M (2004). Bacterial spot of stone fruits in Slovenia. [Proceedings of the IOBC/WPRS Working Group 'Integrated plant protection in stone fruit', Opatjia, Croatia, 14-16 October 2002]. Bulletin OILB/SROP 27(5), 123-125.
CAB International, 1988. Pseudomonas syringae pv. syringae. [Distribution map]. Distribution Maps of Plant Diseases, April (Edition 4). Wallingford, UK: CAB International, Map 336.
HORTIPENDIUM (2013) Pseudomonas syringae pv. syringae. https://hortipendium.de/Pseudomonas_syringae_pv._syringae.
Mansvelt EL & Hattingh MJ (2014). Bacterial blossom blast. In: Compendium of Apple and Pear Diseases and Pests, Second Edition (Eds. Sutton TB, Aldwinckle HS, Agnello AM & Walgenbach JF). American Phytopathological Society - page 92.
Mansvelt EL, Hattingh MJ & Sundin GW (2014). Bacterial blister bark. In: Compendium of Apple and Pear Diseases and Pests, Second Edition (Eds. Sutton TB, Aldwinckle HS, Agnello AM & Walgenbach JF). American Phytopathological Society - pp 92-93.

HOST PLANT N°2: Malus (1MABG) for the Fruits (including hops) sector.

Origin of the listing:

Commission Implementing Directive (EU) 2014/98/EU and Commission Implementing Regulation (EU) 2019/2072

Plants for planting:

Plants intended for planting

3 - Is the pest already listed in a PM4 standard on the concerned host plant?

Conclusion:

Evaluation continues

Justification (if necessary):

4 - Are the listed plants for planting the main* pathway for the "pest/host/intended use" combination? (*: significant compared to others):

Conclusion:

Not candidate

Justification:

5 - Economic impact:

Are there documented reports of any economic impact on the host?

Yes

Justification:

P. syringae pv. syringae can cause bacterial blister bark in apple. The disease can be visible on the bark of apple trees in the spring. Infected regions enlarge and can completely girdle branches. Beneath the outer, tan epidermal layer of the blister is a spongy bark layer of green cells. The blister dries and then flakes off to expose underlying necrotic tissue. Necrosis usually develops at the junction of twigs and branches, at buds, and at pruning wounds. Blight of fruit spurs is found in some orchards. Dead blossoms are dark brown, but the bark surrounding the spurs is usually unaffected. Lesions extending along branches and the main trunk develop early in the summer. Some branches often exhibit terminal dieback, and if the trunk is girdled, the tree dies. The disease is most important on the cultivars Starkrimson, Top Red Delicious, Oregon Spur Delicious, Redchief, Top Red One, Galaxy, Smoothee, and Mondial Gala and on the rootstock Merton 793. Other cultivars that show symptoms include Golden Delicious, Granny Smith, and Starking Delicious (Mansvelt et al., 2014).

What is the likely economic impact of the pest irrespective of its infestation source in the absence of phytosanitary measures? (= official measures)

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?

Conclusion:

Justification:

Canker diseases of fruit trees caused by P. syringae pv. syringae are widespread and may be devastating, causing great losses or requiring much effort to protect plants from them (CABI, 2020).
Remark: Wet weather, high relative humidity, and relatively cool (15-25°C) spring temperatures favors disease development (CABI, 2020).

Conclusion:

Justification:

Use of healthy propagating material, inspection of certified and CAC material and ornamentals several times a year at appropriate vegetative stages, isolation distances between nurseries and other sources of inoculum (host plants in public green, commercial orchards), sampling and testing of certified material. In case of CAC visual inspection, in case of doubts sampling and testing, destroying the infected plants in nursery and additional checks of infested lots.
Good agricultural practices, fungicide treatments (if available active substances), avoiding overfertilization and excessive irrigation, use of tolerant /resistant rootstocks and varieties, if available.

7- Is the quality of the data sufficient to recommend the pest to be listed as a RNQP?

Conclusion:

Justification:

CONCLUSION ON THE STATUS:

Disqualified: plants for planting is not a significant pathway and lack of data on economic impact

8 - Tolerance level:

Is there a need to change the Tolerance level:

Yes

Proposed Tolerance levels:

Delisting

9 - Risk management measures:

Is there a need to change the Risk management measure:

Yes

Proposed Risk management measure:

Delisting

REFERENCES:

Agrios GN (2005). Plant Pathology, 5th Edition. Elsevier Academic Press. 922 pp.
Bradbury JF, 1986. Guide to Plant Pathogenic Bacteria. Wallingford, UK: CAB International.
CABI/EPPO (2012). Pseudomonas syringae pv. syringae. [Distribution map]. Distribution Maps of Plant Diseases, No. October. Wallingford, UK: CABI, Map 336 (Edition 5).
CABI (2020) CPC Crop protection compendium: Pseudomonas syringae pv. syringae (bacterial canker or blast (stone and pome fruits)). 08042024. https://www.cabidigitallibrary.org/doi/abs/10.1079/cabicompendium.45010
Chiriac IP, Lipşa FlD& Ulea E (2014) Comparative study regarding in vitro infections with Erwinia amylovora and Pseudomonas syringae pv. syringae on pomaceae species. Cercetări Agronomice în Moldova XLVIII No. 1 (161) / 2015
Dreo T, Seljak G, Demšar T, Ravnikar M (2004). Bacterial spot of stone fruits in Slovenia. [Proceedings of the IOBC/WPRS Working Group 'Integrated plant protection in stone fruit', Opatjia, Croatia, 14-16 October 2002]. Bulletin OILB/SROP 27(5), 123-125.
CAB International, 1988. Pseudomonas syringae pv. syringae. [Distribution map]. Distribution Maps of Plant Diseases, April (Edition 4). Wallingford, UK: CAB International, Map 336.
HORTIPENDIUM (2013) Pseudomonas syringae pv. syringae. https://hortipendium.de/Pseudomonas_syringae_pv._syringae.
Mansvelt EL & Hattingh MJ (2014). Bacterial blossom blast. In: Compendium of Apple and Pear Diseases and Pests, Second Edition (Eds. Sutton TB, Aldwinckle HS, Agnello AM & Walgenbach JF). American Phytopathological Society - page 92.
Mansvelt EL, Hattingh MJ & Sundin GW (2014). Bacterial blister bark. In: Compendium of Apple and Pear Diseases and Pests, Second Edition (Eds. Sutton TB, Aldwinckle HS, Agnello AM & Walgenbach JF). American Phytopathological Society - pp 92-93.

HOST PLANT N°3: Prunus armeniaca (PRNAR) for the Fruits (including hops) sector.

Origin of the listing:

Commission Implementing Directive (EU) 2014/98/EU and Commission Implementing Regulation (EU) 2019/2072

Plants for planting:

Plants intended for planting

3 - Is the pest already listed in a PM4 standard on the concerned host plant?

Yes

Conclusion:

Evaluation continues

Justification (if necessary):

Inspection for 'Pseudomonas syringae pv. syringae' on apricot is recommended in EPPO Standard PM 4-30 Certification scheme for almond, apricot, peach and plum. However, in responses to the questionnaire, DE, FR and SI supported deregulation (or revising the threshold for FR). DE highlighted the unclear taxonomy making laboratory analysis difficult and the widespread presence of the bacteria as an epiphyte on plants. Evaluation continues applying the full methodology.
Remark: The assessment performed covers the given host species as well as interspecific hybrids with other Prunus species.

4 - Are the listed plants for planting the main* pathway for the "pest/host/intended use" combination? (*: significant compared to others):

Conclusion:

Not candidate

Justification:

Pseudomonas syringae pv. syringae can induce apical necrosis in mango, bacterial canker in Prunus spp., blister bark in apple and blossom blast in pear (e.g. Kennely et al., 2007). It can also cause bacterial canker in apricot (Prunus armeniaca). P. syringae pv. syringae strains able to infect apricot belong to phylogroup 2b and 2d (Parisi et al., 2019; Hulin et al., 2020).
P. syringae pv. syringae is found in soil and water and on plant surfaces worldwide. It is transmitted and disseminated through living plants and vegetative propagation material (CABI, 2020). Pseudomonas syringae can be isolated from apparently healthy plants without disease symptoms being evident for several years, indicating either an epiphytic phase (epiphytic member of the phyllosphere of healthy plants) or the presence of latent infections (Agrios, 2005; CABI, 2020). It is spread by wind driven rain, rain splash, windblown rain, direct contact with the host, insects such as flies and bees, and hands, handling of plants and tools, and movement of infected nursery stock. Under favorable conditions, the bacteria enters the plant through wounds or natural openings such as stomata, and multiply rapidly within the apoplast. Water soaking of tissues during heavy rains greatly favors penetration and invasion. Bacteria multiplies on the walls of host cells, which collapse after disruption of the cell membranes (Agrios, 2005).
In apricot, Pseudomonas syringae survives on plant surfaces, is spread by splashing rain, and is favored by high moisture and low temperatures in spring. The bacterium is commonly found on healthy as well as diseased plants and becomes pathogenic only on susceptible or predisposed trees (UC PMG, 2017 ).
Plants for planting can be a pathway for Pseudomonas syringae pv. syringae, however due to its extensive distribution in the EU and its ease of natural spread, plants for planting are not considered to be a significant pathway compared to others. The Fruit SEWG considered that most orchards or their surrounding are already infested with this pest (CABI, 2020; HORTIPENDIUM, 2013).

5 - Economic impact:

Are there documented reports of any economic impact on the host?

Yes

Justification:

In California, the disease is found almost exclusively in replanted orchards where ring nematodes flourish or in locations where spring frost is a problem. The disease is worse in low, gravelly, sandy spots, soils with shallow claypans (60-90 cm deep), or other soil conditions that lead to weakened growth. vigorous trees are less susceptible to bacterial canker, while young trees (2–8 years old) are most affected. The disease rarely occurs in the first year of planting unless the ground is not fumigated before planting. It is uncommon in nurseries (UC PMG, 2017).
In north-eastern Italy, high sensitivity to Pseudomonas blight/canker of some recently introduced apricot cultivars seemed to be among the main reasons for the recent outbreaks. In Czech Republic, Poland and Slovakia, high differences among the cultivated varieties and their groups of origin were observed (metditerranean and Asian ones were reported more susceptible). Symptomatic sample collection mainly involved new apricot genotypes and never old, traditional varieties cultivated in the same region. In the worst-case scenario, apricot trees infected by Pseudomonas syringae pv syringae rapidly develop large cankers on branches and trunks within a few weeks during the spring and summer or die slowly within 2–3 years (Giovanardi et al., 2018).
In Central Europe (northern limit of apricot growing area) the complex of Pseudomonas is one of the main components of the sudden apricot dieback (apoplexy) and common stone fruit dieback. The pest is common and widespread in practically all the growing areas.
Severity highly depends also on the grafting level (less severe for higher grafting and interstem), plant variety and rootstock type, soil and weather conditions.

What is the likely economic impact of the pest irrespective of its infestation source in the absence of phytosanitary measures? (= official measures)

Medium

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?

Conclusion:

Justification:

Although Pseudomonas syringae pv. syringae is an important disease in apricot, other circumstances (cultivar choice, circumstances under which trees are grown, replating problems - inoculum already present, presence of ring nematodes, etc.) seem to play an important role in the severity of the disease.

Yes

Conclusion:

Justification:

Because disease management is still largely ineffective, a targeted implementation of a disease control strategy should be based on the knowledge of the plant pathogenic bacterial population structure and its features, together with correct agronomic practices, like pruning trees in late wintertime (march-april, for Hungary, Czech Republic, Switzerland and Germany), reducing irrigation and input of nitrate fertilizers, and spraying copper in late autumn to significantly reduce the overwintering inoculum. More tolerant varieties can also be used (Giovanardi et al., 2018; Parisi et al, 2020, Pánková et al., 2020).

7- Is the quality of the data sufficient to recommend the pest to be listed as a RNQP?

Conclusion:

Justification:

CONCLUSION ON THE STATUS:

Disqualified: plants for planting is not a significant pathway

8 - Tolerance level:

Is there a need to change the Tolerance level:

Yes

Proposed Tolerance levels:

Delisting

9 - Risk management measures:

Is there a need to change the Risk management measure:

Yes

Proposed Risk management measure:

Delisting

REFERENCES:

CABI (2020) CPC Crop protection compendium: Pseudomonas syringae pv. syringae (bacterial canker or blast (stone and pome fruits)). 08042024. https://www.cabidigitallibrary.org/doi/abs/10.1079/cabicompendium.45010
Giovanardi D, Ferrante P, Scortichini M, & Stefani,E (2018). Characterisation of Pseudomonas syringae isolates from apricot orchards in north-eastern Italy. European Journal of Plant Pathology 151, 901-917.
HORTIPENDIUM (2013) Pseudomonas syringae pv. syringae. https://hortipendium.de/Pseudomonas_syringae_pv._syringae.
Hulin MT, Jackson RW, Harrison RJ & Mansfield JW (2020). Cherry picking by pseudomonads: After a century of research on canker, genomics provides insights into the evolution of pathogenicity towards stone fruits. Plant Pathology 69(6), 962-978. doi: 10.1111/ppa.13189.
Kennelly MM, Cazorla FM, de Vicente A, Ramos C & Sundin GW (2007) Pseudomonas syringae diseases of fruit trees: progress toward understanding and control. Plant Disease 91(1), 4-17.
Lamichhane JR, Varvaro L, Parisi L, Audergon J-M & Morris CE (2014) Disease and frost damage of woody plants caused by Pseudomonas syringae: seeing the forest for the trees. Advances in Agronomy 126, 235–95.
Parisi L, Morgaint B, Garcia JB, Guilbaud C, Chandeysson C, Bourgeay JF, Moronvalle A, Brun L, Brachet ML & Morris CE (2019) Bacteria from four phylogroups of the Pseudomonas syringae complex can cause bacterial canker of apricot. Plant Pathology 68(7), pp.1249-1258.
Pánková I &Krejzarová R (2020) Detekce původců korových nekróz a předčasného odumírání meruněk a broskvoní, především bakteriemi komplexu Pseudomonas syringae, v množitelských materiálech a v produkčních sadech. Výzkumný ústav rostlinné výroby, v. v. i., Praha, 2020. ISBN 978-80-7427-330-8
UC IPM (2017) Bacterial canker. In Pest management guidelines – Apricot. Publication 3433. University of California Agriculture and Natural Resources. Pages 59-60

HOST PLANT N°4: Pyrus (1PYUG) for the Fruits (including hops) sector.

Origin of the listing:

Commission Implementing Directive (EU) 2014/98/EU and Commission Implementing Regulation (EU) 2019/2072

Plants for planting:

Plants intended for planting

3 - Is the pest already listed in a PM4 standard on the concerned host plant?

Conclusion:

Evaluation continues

Justification (if necessary):

4 - Are the listed plants for planting the main* pathway for the "pest/host/intended use" combination? (*: significant compared to others):

Conclusion:

Not candidate

Justification:

5 - Economic impact:

Are there documented reports of any economic impact on the host?

Yes

Justification:

P. syringae pv. syringae can cause bacterial blossom blast in pear. If weather conditions are favorable, blackening spreads throughout the blossom truss, and the entire spur is killed. The other blossom symptom is calyx-cup infection (individual flowers). This condition is often overlooked and can be confused with poor fruit set. If the lesions on developing fruit spread, the entire fruit and pedicel become blackened. Many of these immature fruit drop. Sunken necrotic areas are present on the infected fruit remaining on the trees. Small, inconspicuous leaf spots and shot holes develop when young, succulent pear leaves are infected by the pathogen. Entire leaves are occasionally killed. Infected spurs usually die. The disease may spread from spurs to branches, but this happens infrequently. Lesions resembling those of blister bark of apple may develop on the surface of infected branches (Mansvelt & Hattingh, 2014).

What is the likely economic impact of the pest irrespective of its infestation source in the absence of phytosanitary measures? (= official measures)

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?

Conclusion:

Justification:

Conclusion:

Justification:

7- Is the quality of the data sufficient to recommend the pest to be listed as a RNQP?

Conclusion:

Justification:

CONCLUSION ON THE STATUS:

Disqualified: plants for planting is not a significant pathway and lack of data on economic impact

8 - Tolerance level:

Is there a need to change the Tolerance level:

Yes

Proposed Tolerance levels:

Delisting

9 - Risk management measures:

Is there a need to change the Risk management measure:

Yes

Proposed Risk management measure:

Delisting

REFERENCES:

Agrios GN (2005). Plant Pathology, 5th Edition. Elsevier Academic Press. 922 pp.
Bradbury JF, 1986. Guide to Plant Pathogenic Bacteria. Wallingford, UK: CAB International.
CABI/EPPO (2012). Pseudomonas syringae pv. syringae. [Distribution map]. Distribution Maps of Plant Diseases, No. October. Wallingford, UK: CABI, Map 336 (Edition 5).
CABI (2020) CPC Crop protection compendium: Pseudomonas syringae pv. syringae (bacterial canker or blast (stone and pome fruits)). 08042024. https://www.cabidigitallibrary.org/doi/abs/10.1079/cabicompendium.45010
Chiriac IP, Lipşa FlD& Ulea E (2014) Comparative study regarding in vitro infections with Erwinia amylovora and Pseudomonas syringae pv. syringae on pomaceae species. Cercetări Agronomice în Moldova XLVIII No. 1 (161) / 2015
Dreo T, Seljak G, Demšar T, Ravnikar M (2004). Bacterial spot of stone fruits in Slovenia. [Proceedings of the IOBC/WPRS Working Group 'Integrated plant protection in stone fruit', Opatjia, Croatia, 14-16 October 2002]. Bulletin OILB/SROP 27(5), 123-125.
CAB International, 1988. Pseudomonas syringae pv. syringae. [Distribution map]. Distribution Maps of Plant Diseases, April (Edition 4). Wallingford, UK: CAB International, Map 336.
HORTIPENDIUM (2013) Pseudomonas syringae pv. syringae. https://hortipendium.de/Pseudomonas_syringae_pv._syringae.
Mansvelt EL & Hattingh MJ (2014). Bacterial blossom blast. In: Compendium of Apple and Pear Diseases and Pests, Second Edition (Eds. Sutton TB, Aldwinckle HS, Agnello AM & Walgenbach JF). American Phytopathological Society - page 92.
Mansvelt EL, Hattingh MJ & Sundin GW (2014). Bacterial blister bark. In: Compendium of Apple and Pear Diseases and Pests, Second Edition (Eds. Sutton TB, Aldwinckle HS, Agnello AM & Walgenbach JF). American Phytopathological Society - pp 92-93.