Desmedipham

Toxicity to terrestrial plants

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to terrestrial plants: long-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2006-01-04 to 2006-05-26

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 208 (Terrestrial Plants Test: Seedling Emergence and Seedling Growth Test)

Version / remarks:

July 2000

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

The test material is in a liquid form.

Analytical monitoring:

no

Vehicle:

yes

Remarks:

de-ionised water

Details on preparation and application of test substrate:

The spray chamber was calibrated before application, using glass plates and calculating the application volume from the difference between the tare of the plates and the weight after application within 3 consecutive runs. The mean output of the sprayer was 229 L/ha with a CV of 0.39% for oilseed rape, radish, soybean, tomato, onion, oat and ryegrass, 230 L/ha with a CV of 1.00% for carrot and 247 L/ha with a CV of 2.39% for lettuce and cucumber. Based on the mean output volume of the sprayer the required amount of the test item had been calculated per treatment based on the mix volume used for application. For this mix volume the amount of test item had been weighed, using a scale type LA 310 S (Sartorius) and was dissolved in the respective water volume (Appendix 2). The application took place immediately after mixing of the spray solution. Application was done by means of a laboratory application chamber ‘Spraylab 210/110 – SPS’, Schachtner, Ludwigsburg, Germany. The rates applied to all species is given in Table 5.

Species:

Daucus carota

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Carrot
- Plant family: - Apiaceae
- Variety: Finaro, F1
- Source of seed: Hild

Species:

Lactuca sativa

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Lettuce
- Plant family: - Asteraceae
- Variety: Edox
- Source of seed: Hild

Species:

Brassica napus

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Oilseed rape
- Plant family: Brassicaceae
- Variety: Talent
- Source of seed: Lembke

Species:

Raphanus sativus

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Radish
- Plant family: Brassicaceae
- Variety: Helox
- Source of seed: Hild

Species:

Cucumis sativus

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Cucumber
- Plant family: Curcubitaceae
- Variety: Flamingo, F1
- Source of seed: Hild

Species:

Glycine max (G. soja)

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Soybean
- Plant family: Fabaceae
- Source of seed: Asia market

Species:

Lycopersicon esculentum

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Tomato
- Plant family: Solanaceae
- Variety: Diplom, F1
- Source of seed: Hild

Species:

Allium cepa

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

- Common name: Onion
- Plant family: Liliaceae
- Variety: Red Baron
- Source of seed: Hild

Species:

Avena sativa

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

- Common name: Oat
- Plant family: Poaceae
- Variety: Aragon
- Source of seed: Nordsaat

Species:

other: Lolium multiflorum

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

- Common name: Ryegrass
- Plant family: Poaceae
- Variety: Lipo
- Source of seed: DSV

Test type:

seedling emergence toxicity test

Study type:

laboratory study

Substrate type:

other: a mixture of natural soil and peat-culture substrate (TKS-1). This mixture was silty sand.

Limit test:

yes

Total exposure duration:

21 d

Remarks:

Plants were cultivated for 21 days (28 days for carrot and onion) under greenhouse conditions. At harvest the plants which survived were counted. Survived plant means that there was at least one green part at a plant.

Test temperature:

Daily mean temperature: 17.0°C - 23.3°C

pH:

6.7 -6.94

Moisture:

Daily mean relative humidity: 40.9% - 69.8%

Details on test conditions:

TEST SYSTEM
- Testing facility: Greenhouse chamber
- Test container (type, material, size): Plastic containers with 11 cm or 12 cm in diameter (species dependent)
- No. of seeds per container: 3 - 10 seeds per pot (plant species dependent)
- No. of replicates per treatment group: 4 to 10 replicates/variant (plant species dependent)

GROWTH CONDITIONS
- Photoperiod: =14-hours light
- Light source: Natural day length with addition of artificial light if outdoor light intensity was lower than 10 klux.
- Relative humidity (%): 40.9% - 69.8%
- Water source/type: Rain water cleaned with a mechanical filtration device.
- Any pest control method/fertilization (if used): No additional pesticides had been applied. Fertiliser was added to each pot on a weekly basis with a NPK-fertiliser (Substral Universaldünger) as a 0.15% solution. N-fertiliser (Gabi Plus N) was added as needed.
- Phytotoxicity rating system: A scale of 0 – 100% where 0% means no difference to untreated and 100% plant is dead

Nominal and measured concentrations:

Nominal concentration: 1.5 L/ha

Key result

Species:

other: All plant species tested

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.18 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Remarks on result:

other: converted endpoint (from L/ha to mg/kg soil dw)

Key result

Species:

other: All plant species tested

Duration:

21 d

Dose descriptor:

other: NOER

Effect conc.:

1.5 other: L/ha

Nominal / measured:

nominal

Conc. based on:

other: formulation

Basis for effect:

seedling emergence

Details on results:

To assure trial validity the study plan requested the limits for the untreated control concerning plant emergence, plant damages and biomass coefficient of variation. All the criteria were fulfilled within each plant species tested (Table 9). In carrot and onion one seed respectively brought up a malformed germ which is due to normal variation in seed quality. These germs were not considered as phytotoxic damaged. Thus the trial can be considered as valid.

Plant emergence and plant survival
All plant species besides carrot and onion had reached a 50 % emergence rate after 7 days. The both mentioned species reached the 50% emergence rate 14 days after treatment. None of the tested plant species was adversely affected concerning seedling emergence or plant survival by the application of AE B038584 01 EC31 A1. A summary of the plant stand counted every 7 days within trial period is given in table 10. Additionally, the total sum of emerged plants per species is given in column ‘emerged plants per pot’ in Table 10. The difference between both data sets is due to plants which died within trial period and thus the plant stand count after 21 days represent not the sum of total emerged plants.

Phytotoxicity
No phytotoxic symptoms were detected in lettuce and cucumber. The other tested plant species showed only slight symptoms (below 10%) mainly necrosis and stunting after application of AE B038584 01 EC31 A1 (Table 11).

Biomass
The plant biomass (shoot fresh weight) was determined 21 DAA (carrot an onion 28 DAA). No influence of AE B038584 01 EC31 A1 on plant weight was observed in all tested plant species besides tomato. Tomato showed a significant reduction of 15 % after application of 1.500 L AE B038584 01 EC31 A1/ha (Table 12).

The trial was conducted under stable and controlled environmental conditions. Temperature conditions ensured a good growth of plants. Additional light supply was added when necessary. All maintenance was done according to good horticultural practice and was adapted to each pot. Plant growth and biomass production of all plant species showed no problems in the untreated control. Summarising these aspects there are no unusual test conditions affecting the study. Conclusively the study is suited to determine worst case effect rates for the tested plant species. All emerged control plants remained healthy throughout the entire trial period. Only in carrot and onion one seedling emerged malformed and died before end of the test. This should be due to the variation in seed quality and does not influence the result of this study.

 

See "Attachments" in "Overall remarks, attachments" for the appendixes and tables.

Validity criteria fulfilled:

yes

Conclusions:

The rate of emergence in the controls was > 70% for all tested plant species. Thus any adverse influences on the study results can be excluded and the study can be considered as valid. No impact could be found in emergence rate and plant survival of all tested plant species. Only slight necrosis and stunting were found. In tomato an impact on biomass was found with a significant reduction of 15% but no ER value could be calculated. Within this seedling emergence test no endangered plant species could be detected after application of 1.5 L AE B038584 01 EC31 A1/ha.

Executive summary:

The test item AE B038584 01 EC31 A1 exposed to 10 plant species under worst case greenhouse conditions did not cause adverse effects to seedling emergence of all tested plant species. The calculated NOER was 0.18 mg a.s./kg soil dw.

Reference 2

Endpoint:

toxicity to terrestrial plants: long-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2006-01-16 to 2006-05-29

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 208 (Terrestrial Plants, Growth Test)

Version / remarks:

July 2000

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

The test material is in a liquid form.

Analytical monitoring:

yes

Details on sampling:

Samples of spray solution had been taken from all treatments before application and were stored at =-18°C. Samples (untreated control and highest tested rate) were sent for analysis, but the details were not reported.

Vehicle:

no

Details on preparation and application of test substrate:

The spray chamber was calibrated before each application, using glass plates and calculating the application volume from the difference between the tare of the plates and the weight after application within 3 consecutive runs. The mean output of the sprayer was 230 L/ha with a CV of 1.0% for radish, soybean, oat and ryegrass, 247 L/ha with a CV of 2.4% for lettuce, oilseed rape, cucumber and tomato, 248 L/ha with a CV of 0.7% for carrot and 273 L/ha with a CV of 1.5% for onion. The rates of the test material given in Table 5 were applied (details see Appendix 2). The application took place immediately after mixing the spray solution. Application was done by means of a laboratory application chamber ‘Spraylab 210/110 – SPS’, Schachtner, Ludwigsburg, Germany.

Species:

Daucus carota

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Carrot
- Plant family: - Apiaceae
- Variety: Finaro, F1
- Source of seed: Hild

Species:

Lactuca sativa

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Lettuce
- Plant family: - Asteraceae
- Variety: Estelle
- Source of seed: Hild

Species:

Brassica napus

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Oilseed rape
- Plant family: Brassicaceae
- Variety: Talent
- Source of seed: Lembke

Species:

Raphanus sativus

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Radish
- Plant family: Brassicaceae
- Variety: Helox
- Source of seed: Hild

Species:

Cucumis sativus

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Cucumber
- Plant family: Curcubitaceae
- Variety: Profi
- Source of seed: Hild

Species:

Glycine max (G. soja)

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Soybean
- Plant family: Fabaceae
- Variety: Merlin
- Source of seed: Linz

Species:

Lycopersicon esculentum

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: Tomato
- Plant family: Solanaceae
- Variety: Diplom
- Source of seed: Hild

Species:

Allium cepa

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

- Common name: Onion
- Plant family: Liliaceae
- Variety: Element, F1
- Source of seed: Hild

Species:

Avena sativa

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

- Common name: Oat
- Plant family: Poaceae
- Variety: Aragon
- Source of seed: Nordsaat

Species:

other: Lolium multiflorum

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

- Common name: Ryegrass
- Plant family: Poaceae
- Variety: Lipo
- Source of seed: DSV

Test type:

vegetative vigour test

Study type:

laboratory study

Substrate type:

other: a mixture of natural soil and peat-culture substrate (TKS-1). This mixture was silty sand.

Limit test:

no

Total exposure duration:

21 d

Test temperature:

16.0°C – 22.1°C (extremes ranged from 7.3°C (for short time only) to 35.8°C)

pH:

6.7 - 6.94

Moisture:

Daily mean relative humidity within the trial period ranged from 43.5% and 73.0% (extremes 16% and 84% relative humidity).

Details on test conditions:

TEST SYSTEM
- Testing facility: Greenhouse chamber
- Test container (type, material, size): plastic containers with a diameter of 12 and 14 cm and a height of 9 and 10.5 cm
- No. of seeds per container: 3 to 10 plants per pot (species dependent)
- No. of replicates per treatment group: 4 to 9 replicates per variant (species dependent)

GROWTH CONDITIONS
- Photoperiod: 14-hours light
- Light source: The natural day length during the study period was adjusted to 14 hours by adding artificial light if outdoor light intensity was lower than 10 klux. Additional light was necessary within the study period.
- Relative humidity (%): 43.5% - 73.0%
- Water source/type: Rain water cleaned with a mechanical filtration device.
- Any pest control method/fertilization (if used): Fertiliser was added to each pot according to the specific needs of the plants with a liquid NPK-fertiliser (Substral Universaldünger) as a 0.15% solution. N-fertiliser (Gabi Plus “N”) was added as needed. All pots of one plant species and treatment rate obtained the same level of fertiliser during the trial (Table 4).
- Phytotoxicity rating system: A scale of 0 – 100% where no differences to the control are given by 0% and 100% indicates complete plant effected.

Nominal and measured concentrations:

Nominal concentration: 0.094, 0.188, 0.375, 0.750 and 1.500 L/ha

Reference substance (positive control):

no

Key result

Species:

Raphanus sativus

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.01 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: fresh weight

Remarks on result:

other: converted endpoint (from L/ha to mg/kg soil dw)

Key result

Species:

Raphanus sativus

Duration:

21 d

Dose descriptor:

other: NOER

Effect conc.:

0.094 other: L/ha

Nominal / measured:

nominal

Conc. based on:

other: formulation

Basis for effect:

other: fresh weight

Details on results:

Phytotoxicity
All tested plant species showed phytotoxic symptoms visible as chlorosis, necrosis and plant stunting. The main effect of AE B038584 01 EC31 A1 was on plant growth. All tested plant species besides oat and ryegrass showed distinct growth reduction at the highest tested rate of 1.500 L AE B038584 01 EC31 A1/ha. In cucumber, soybean and tomato the highest tested rate of 1.500 L AE B038584 01 EC31 A1/ha caused heavy stunting and necrosis of about 50% and 30%, respectively. At 1.500 L AE B038584 01 EC31 A1/ha radish and onion showed also severe necrosis of about 96 % and 76 % respectively (Table 10).

Plant survival
No significant plant mortality compared to the untreated control was found for all plant species besides oilseed rape, radish, cucumber and tomato (Table 11). The highest tested rate of 1.500 L AE B038584 01 EC31 A1/ha reduced plant stand in radish by 97%, in tomato by 16% and in oilseed rape and cucumber by 7%. In radish a rate of 0.750 L AE B038584 01 EC31 A1/ha caused a significant mortality of about 60%. To detect LR50 values inhibitions lower or equal 0% or greater or equal 100% were replaced by 0.100 and 99.900 respectively (Table 12). Only in radish a LR50 of 0.667 L AE B038584 01 EC31 A1/ha could be calculated.

Biomass
AE B038584 01 EC31 A1 reduced plant fresh weight in all tested plant species besides oat. Significant biomass reductions could be found after application of the lowest tested rate of 0.094 L AE B038584 01 EC31 A1/ha in radish, after application of =0.188 L AE B038584 01 EC31 A1/ha in onion, after application of =0.375 L AE B038584 01 EC31 A1/ha in carrot, cucumber, soybean and tomato and after =1.500 L AE B038584 01 EC31 A1/ha in oilseed rape and ryegrass. Lettuce showed significant effects in the lowest tested rate, but when the next higher rate was not significant and the total biomass reduction in the lowest tested rate was by about 6% only, the NOER was set to 0.188 L AE B038584 01 EC31 A1/ha. More than 80% biomass reduction were caused by 0.750 L AE B038584 01 EC31 A1/ha in radish whilst 1.500 L/ha caused 100% dead plants (Table 13).

No NOER could be calculated in radish due to significant weight loss even in the lowest tested rate. No ER50 for plant fresh weight reduction could be found for 6 plant species up to 1.500 L AE B038584 01 EC31 A1/ha. The lowest ER50 for biomass reduction were calculated for radish and onion with 0.318 and 0.775 L AE B038584 01 EC31 A1/ha, respectively.

Discussion

The trial was conducted under stable and controlled environmental conditions. Temperature conditions ensured a good growth of plants. Additional light supply was added when necessary. All maintenance was done according to good horticultural practice and was adapted to each pot. Plant growth and biomass production of all plant species showed no problems in the untreated control. Summarising these aspects there are no unusual test conditions affecting the study. Conclusively the study is suited to determine worst case effect rates for the tested plant species.

 

All control plants remained healthy throughout the entire trial period. Thus any adverse influences on the study results can be excluded and the study can be considered as valid.

 

Plant mortality was significantly increased after application of 0.750 L AE B038584 01 EC31 A1/ha in radish, after application of 1.500 L AE B038584 01 EC31 A1/ha in oilseed rape and tomato. The highest tested rate of 1.500 L AE B038584 01 EC31 A1/ha reduced plant stand in radish by 97% and in oilseed rape and tomato 7%. For radish a LR₅₀ of 0.667 LAE B038584 01 EC31 A1/ha could be calculated.

 

Biomass of all tested plant species besides oat was reduced by AE B038584 01 EC31 A1 at least within the highest tested rate.

 

Significant biomass reductions could be found after application of the lowest tested rate of 0.094 L AE B038584 01 EC31 A1/ha in radish, after application of ≥0.188 L AE B038584 01 EC31 A1/ha in onion, after application of ≥0.375 L AE B038584 01 EC31 A1/ha in carrot, cucumber, soybean and tomato and after ≥1.500 L AE B038584 01 EC31 A1/ha in oilseed rape and ryegrass. Lettuce showed significant effects in the lowest tested rate, but when the next higher rate was not significant and the total biomass reduction in the lowest tested rate was by about 6% only, the NOER was set to 0.188 L AE B038584 01 EC31 A1/ha.

 

More than 80% biomass reduction were caused by 0.750 L AE B038584 01 EC31 A1/ha in radish whilst 1.500 L/ha caused nearly 100% dead plants.

 

No NOER could be calculated in radish due to significant weight loss even in the lowest tested rate.

 

The lowest ER₅₀ for biomass reduction were calculated for radish and onion with 0.318 and 0.775 L AE B038584 01 EC31 A1/ha, respectively.

 

Thus radish (Brassicaceae) was the most sensitive plant species.

 

See "Attachments" in "Overall remarks, attachments" for the appendixes and tables.

Validity criteria fulfilled:

yes

Remarks:

plant survival in untreated pots was =90%, phytotoxic damages in untreated pots was 0%, variance of biomass data within control pots was =20%, and the r² for dose response curve (in case of =50% effect) was =0.7.

Conclusions:

Based on the results of this study, conducted under worst case greenhouse conditions, it can be concluded that AE B038584 01 EC31 A1 did cause adverse effects to the vegetative vigour of nearly all tested plant species. The most sensitive species was radish. LR50 for the parameter plant mortality could only be found in radish with 0.667 L AE B038584 01 EC31 A1/ha. The lowest ER50 for biomass reduction were calculated for radish with 0.318 L AE B038584 01 EC31 A1/ha.

Executive summary:

The test item AE B038584 01 EC31 A1 exposed to 10 plant species did cause adverse effects to the vegetative vigour of nearly all tested plant species. The most sensitive species was radish. LR₅₀ for the parameter plant mortality could only be found in radish with 0.667 L AE B038584 01 EC31 A1/ha. The lowest ER₅₀ for biomass reduction were calculated for radish with 0.318 L AE B038584 01 EC31 A1/ha. The NOER was calculated to be <0.0097 mg a.s./kg soil dw.

Description of key information

Vegetative vigour study: Following a foliar application of Desmedipham at 0.094 L/ha to 1.5 L/ha to ten terrestrial plant species at the 2 to 4 leaf stage all tested plant species showed phytotoxic symptoms visible as chlorosis, necrosis and plant stunting. The lowest NOER (NOEC)(radish) was determined to be <0.094 L formulation/ha (corresponding to <0.0097 mg Desmedipham/kg soil dw).

 

Seedling emergence study: Following a soil surface application of Desmedipham 1.500 L/ha to ten terrestrial plant species at the 2 to 4 leaf stage all tested plant species to ten non-target terrestrial plant species, no adverse effects on emergence, seedling survival and biomass exceeding 50% effect were observed. The NOER (NOEC) was determined to be 1.5 L formulation/ha (corresponding to 0.18 mg Desmedipham/kg soil dw).

In the table below all available studies are listed. For some studies only the results are presented since they are not considered relevant due to the reasons given under “Assessment”. All available studies have been evaluated within the scope of Plant Protection Regulation in the respective Draft Renewal Assessment Report (DAR) under Regulation (EC) 1107/2009.

Test species	Result	Assessment	Reference
10 plant species: carrot (Daucus carota L.); lettuce (Lactuca sativa L.); oilseed rape (Brassica napus L.); radish (Raphanus sativus L. var. sativus); cucumber (Cucumis sativus L.); soybean (Glycine max L.) tomato (Lycopersicon esculentum MILL.); onion (Allium cepa L.); oat (Avena sativa L.); ryegrass (Lolium multiflorum LAM.) – with radish been the most sensitive specie	NOER <0.094 L formulation/ha NOEC <0.0097 mg Desmedipham/kg soil dw	Key study	Brockmann & Teresiak (2006)
10 plant species: carrot (Daucus carota L.); lettuce (Lactuca sativa L.); oilseed rape (Brassica napus L.); radish (Raphanus sativus L. var. sativus); cucumber (Cucumis sativus L.); soybean (Glycine max L.) tomato (Lycopersicon esculentum MILL.); onion (Allium cepa L.); oat (Avena sativa L.); ryegrass (Lolium multiflorum LAM.)	NOER = 1.5 L formulation/ha NOEC = 0.18 mg Desmediphm/kg soil dw	Key study	Brockmann & Teresiak (2006)

Key value for chemical safety assessment

Long-term EC10, LC10 or NOEC for terrestrial plants:

0.01 mg/kg soil dw