NAME OF THE ORGANISM: Cadophora gregata (Phialophora gregata) (PHIAGR)
GENERAL INFORMATION ON THE PEST
Name as submitted in the project specification (if different to the preferred name):
Pest category:
Fungi
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: Oil and fibre plants sector
Is it justified that the pest is listed at a taxonomic rank below species level?
Not relevant
Conclusion:
- Candidate: Oil and fibre plants sector
2 – Status in the EU:
Is this pest already a quarantine pest for the whole EU?
No
Presence in the EU:
Yes
List of countries (EPPO Global Database):
Croatia (2007)
Conclusion:
candidate
Justification (if necessary):
Data of the presence of this pest on the EU territory are available in EPPO Global Database (https://gd.eppo.int/).
HOST PLANT N°1: Glycine max (GLXMA) for the Oil and fibre plants sector.
Origin of the listing:
3 - Oil and fibre plants sector: Council Directive 2002/57/EC
Plants for planting:
Seeds
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):
No
Conclusion:
Not candidate
Justification:
Only one reference to the possible seed-borne nature of this pathogen could be found, which said there was a reduced seedling emergence in the field, though no further details were given available in the abstract (Ellis et al., 1979).
Phialophora gregata is associated with soil residues (Zecchinelli & Gaudenzi, 2002) and these authors implied that as Directive 92/9/EEC (now 2002/57) requires that inert material should not exceed 0.3% of the total weight of a seed sample, this will help with control. The pest is not mentioned by name in the directive. In a rotation experiment, Phialophora gregata infection was lower, plant height and seed size were greater and yield was 13% higher than in an area continually cropped for four years (Kennedy & Lambert, 1981). Incidence of Phialophora gregata is reduced by soil fumigation and seed yields are increased (Gray, 1978). The use of a conventional tillage system significantly decreases the inoculum density of the pathogen. A reduction of the saprophytic population decreases its capability to overwinter and, therefore, results in a lower infection pressure during the next year (Adee & Grau, 1992).
The above information suggests crop debris or soil borne carry-over sources are more important pathways compared to possible seed-borne infection.
Phialophora gregata is associated with soil residues (Zecchinelli & Gaudenzi, 2002) and these authors implied that as Directive 92/9/EEC (now 2002/57) requires that inert material should not exceed 0.3% of the total weight of a seed sample, this will help with control. The pest is not mentioned by name in the directive. In a rotation experiment, Phialophora gregata infection was lower, plant height and seed size were greater and yield was 13% higher than in an area continually cropped for four years (Kennedy & Lambert, 1981). Incidence of Phialophora gregata is reduced by soil fumigation and seed yields are increased (Gray, 1978). The use of a conventional tillage system significantly decreases the inoculum density of the pathogen. A reduction of the saprophytic population decreases its capability to overwinter and, therefore, results in a lower infection pressure during the next year (Adee & Grau, 1992).
The above information suggests crop debris or soil borne carry-over sources are more important pathways compared to possible seed-borne infection.
CONCLUSION ON THE STATUS:
Disqualified: crop debris or soil borne carry-over sources are more important pathways compared to possible seed-borne infection.
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:
- Adee E A & Grau C R (1992) Influence of tillage method on inoculum density of Phialophora gregata in overwintering soybean residue. Presentation at the 1992 APS/MPS Annual Meeting, Portland, OR, USA. Phytopathology 82, 1158;
- Bonato E & Costamilan L (1996) Performance of soyabean genotypes in areas with different levels of infestation by Phialophora gregata. Fitopatologia Brasileira 21, 275-280;
- Ellis MA, Pascha EH, Powell PE & Tenne FD (1979) Internally seedborne fungi of soya bean in Puerto Rico and their effect on seed germination and field emergence. Tropical Agriculture 56, 171-174;
- Kennedy B & Lambert J (1981) Influence of brown stem rot and cropping history on soybean performance. Plant Disease 65, 896-897;
- McCabe C, Singh A K, Leandro L F, Cianzio S & Graham M (2016) Identifying new sources of resistance to brown stem rot in soybean. Crop Science 56, 2287-2296;
- Zecchinelli R & Gaudenzi S (2002) Plant health requirements envisaged by the quality norms for seeds of soyabeans. Sementi Elette 48, 31-33;