mancozeb (ISO); manganese ethylenebis(dithiocarbamate) (polymeric) complex with zinc salt  

Toxicity to terrestrial plants

Link to relevant study record(s)

Reference

Endpoint:

toxicity to terrestrial plants: long-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010-05-11 to 2010-07-30

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 227 (Terrestrial Plant Test: Vegetative Vigour Test)

Version / remarks:

adopted 19 July 2006

Deviations:

yes

Remarks:

deviations with minimal impact on the overall scientific integrity of the study: temperature and humidity were out with the ranges recommended in the test guideline; several species displayed some mild symptoms of phytotoxicity.

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Vehicle:

no

Details on preparation and application of test substrate:

The treatment concentration was prepared prior to use of 4.59 g of Tridex 75 DG. The test item was dispersed in 1000 mL of deionised water to prepare a solution which when sprayed at 400 L/ha applied 1836 g product/ha. Treatments were applied to the plants using a Track Sprayer (Those Engineers Ltd, London, U.K.) at a spray pressure of 2 bar. The sprayer was calibrated prior to the application of the test concentrations to give an application volume equivalent to 413 L/ha (range of 400 - 425 L/ha). The control plants were treated at the same spray rate with deionised water followed by the Tridex 75 DG treatment. Once the spray had dried the plants were transferred to the glasshouse.

Species:

Allium cepa

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

- Common name: onion
- Plant family: Amaryllidaceae
- Variety: not specified
- Source of seed: Moles Seeds (UK) Ltd , Colchester CO3 8PD, UK
- Seed storage: refrigeration

Species:

Avena sativa

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

- Common name: oats
- Plant family: Poaceae
- Variety: not specified
- Source of seed: Herbiseed, Twyford RG10 0NJ, UK
- Seed storage: refrigeration

Species:

Daucus carota

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: carrot
- Plant family: Apiaceae
- Variety: not specified
- Source of seed: Moles Seeds (UK) Ltd , Colchester CO3 8PD, UK
- Seed storage: refrigeration

Species:

Brassica oleracea var. capitata

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: cabbage
- Plant family: Brassicaceae
- Variety: not specified
- Source of seed: Herbiseed, Twyford RG10 0NJ, UK
- Seed storage: refrigeration

Species:

Glycine max (G. soja)

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: soy bean
- Plant family: Fabaceae
- Source of seed: Syngenta Seeds Ltd , Cambridge CB21 5XE, UK
- Seed storage: refrigeration

Species:

Lycopersicon esculentum

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: tomato
- Plant family: Solanacea
- Variety: not specified
- Source of seed: Moles Seeds (UK) Ltd , Colchester CO3 8PD, UK
- Seed storage: refrigeration

Test type:

vegetative vigour test

Study type:

laboratory study

Substrate type:

natural soil

Remarks:

sandy loam (USDA Classification); commercially available soil supplied by Boughton Loam and Turf Management, Kettering, NN16 8UN, UK

Limit test:

yes

Total exposure duration:

21 d

Post exposure observation period:

none

Test temperature:

12.3 - 42.2 °C

Moisture:

25.7 - 99.7 %

Details on test conditions:

TEST SYSTEM
- Test container: non-porous plastic pots (15 cm diameter) with a saucer under each pot
- No. of seeds per container: 3 seeds in each plant pot for tomato and soya
bean, 4 seeds per plant pot for carrot and cabbage and 5 seeds per plant pot for oats and onion
- No. of replicates per treatment group: 4
- No. of replicates per control: 4

SOURCE AND PROPERTIES OF SUBSTRATE
Source: Boughton Loam BL/003/10
- Soil texture
- % sand: 72
- % silt: 14
- % clay: 13
- Soil taxonomic classification: sandy loam
- Organic carbon (%): 1.5
- Electrical Conductivity (1:5 water): 240 uS/cm
- pH: 7.1

GROWTH CONDITIONS
- Photoperiod: 15-16 hours light, 8-9 hours darkness
- Light source: daylight
- Light intensity and quality: 3430-17500 Lux
- Day/night temperatures: 12.7/40.1 °C (mean)
- Relative humidity (%): 26,8 - 95.5 (mean)
- Wind velocity: not specified
- Air exchange rate: not specified
- Watering regime and schedules: Watering was checked and carried out at least every two days over the test period.
- Water source/type: deionised water
- Any pest control method/fertilization: no pest control during test

EFFECT PARAMETERS MEASURED : All test plants were observed for phytotoxicity and mortality at 7, 14 and 21 DAT. After the final observation at 21 days after treatment (DAT), the shoot height of each plant was measured and recorded. Individual plants in each treatment replicate were harvested at the soil surface, fresh weight was recorded and then dry weight was determined following drying in an oven set at 60°C.

Nominal and measured concentrations:

Nominal: 1836 g product/ha
Measured: The results confirmed that the concentration of mancozeb was 116 % of nominal concentration and was within the range 80 to 120%, which means the results for the study can be based on the nominal concentration of Tridex 75 DG in the spray solution.

Reference substance (positive control):

no

Key result

Species:

Lycopersicon esculentum

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

21 g/ha

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

phytotoxicity

Remarks on result:

other: corresponding to 1408 g a.s./ha; re-calculated: 1.872 mg/kg soil dw

Key result

Species:

Glycine max (G. soja)

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

1 836 g/ha

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

phytotoxicity

Remarks on result:

other: corresponding to 1408 g a.s./ha; re-calculated: 1.872 mg/kg soil dw

Key result

Species:

Brassica oleracea var. capitata

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

1 836 g/ha

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

phytotoxicity

Remarks on result:

other: corresponding to 1408 g a.s./ha; re-calculated: 1.872 mg/kg soil dw

Key result

Species:

Daucus carota

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

1 836 g/ha

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

phytotoxicity

Remarks on result:

other: corresponding to 1408 g a.s./ha; re-calculated: 1.872 mg/kg soil dw

Key result

Species:

Avena sativa

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

1 836 g/ha

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

phytotoxicity

Remarks on result:

other: corresponding to 1408 g a.s./ha; re-calculated: 1.872 mg/kg soil dw

Key result

Species:

Allium cepa

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

1 836 g/ha

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

phytotoxicity

Remarks on result:

other: corresponding to 1408 g a.s./ha; re-calculated: 1.872 mg/kg soil dw

Details on results:

DETAILS ON RESULTS
The growth of the control plants was good for all species, confirming satisfactory crop performance in the glasshouse during the study period. Plant quality was excellent; plants of each species were vigorous with good foliage colour.

There was no effect on the survival (mortality) of the treated plants for all the species (100% survival). The percentage difference from the control in shoot height for all species ranged from -5.3 to + 5.0 % with the dry shoot weight ranging from -8.0 to +13.8%.

Onion:
Onion displayed some slight chlorotic phytotoxicity to some plants in the control but there was no treatment related phytotoxicity. It was established that Tridex 75 DG at a rate of 1836 g product/ha did not affect the survival, shoot height, fresh weigh or dry weight in the onion. The NOER and LOER were 1836 g product/ha and >1836 g product/ha respectively.


Soya bean:
Soya bean displayed no phytotoxicity symptoms in the control or the treatment at 1836 g product/ha.


Oat:
Oat displayed some stunting to some plants in the control and 1836 g product/ha treatment concentration; no other visible phytotoxicity symptoms were observed. It was established that Tridex 75 DG at a rate of 1836 g product/ha did not affect the survival, shoot height, fresh weight or dry weight in the oat. The NOER and LOER were 1836g product/ha and >1836 g product/ha respectively.


Cabbage:
Cabbage displayed no phytotoxicity symptoms in the control or the treatment at 1836 g product/ha treatment concentration. It was established that Tridex 75 DG at a rate of 1836 g product/ha did not affect the survival, shoot height, fresh weigh or dry weight in the cabbage. The NOER and LOER were 1836 g product/ha and >1836 g product/ha respectively.


Carrot:
Carrot displayed some slight chlorotic phytotoxicity to some plants in the control and some slight morphological effect (leaf curl) at the 1836 g product/ha treatment concentration. It was established that Tridex 75 DG at a rate of 1836 g product/ha did not affect the survival, shoot height, fresh weigh or dry weight in the carrot. The NOER and LOER were 1836 g product/ha and >1836 g product/ha respectively.


Tomato:
Tomato displayed some slight stunting to some plants in the control and 1836 g product/ha treatment concentration; no other visible phytotoxicity symptoms were observed. It was established that Tridex 75 DG at a rate of 1836 g product/ha did not affect the survival, shoot height, fresh weigh or dry weight in the tomato. The NOER and LOER were 1836 g product/ha and >1836 g product/ha respectively.


VALIDITY OF THE STUDY
This study has been deemed to have fulfilled the validity criteria stated in the guideline OECD 227 in that the germination for all the species was at least 70 % and the overall mean control plant survival was >90 % for all the species. The oat, onion, carrot and tomato control plants did display some mild visible signs of phytotoxic injury to individual plants but all replicates maintained good growth throughout the study. Environmental conditions for each particular plant species, control and treatments, were identical.

Reported statistics and error estimates:

Statistical analysis was performed (ToxCalc, 1999) on the survival, shoot height, foliar fresh and dry shoot weight data for each plant species using the Dunnett's Test Hypothesis Test (two tailed, p<0.05) to determine if there was a significant difference from the control. A NOER and LOER were derived.

For tables please refer to below section on "Attached background material".

Validity criteria fulfilled:

yes

Conclusions:

In a study according to OECD TG 227 the 21-day ER50 and NOEC for the test item was determined to be > 1836 g product/ha and 1836 g product/ha (nominal), which corresponds to >1408 g a.s./ha and 1408 g a.s./ha, respectively. This value was re-calculated to be 1.872 mg/kg soil dw. The NOER (all effects) was assessed to be 1836 g product/ha (corresponding to 1408 g a.s./ha and 1.872 mg/kg soil dw, respectively).

Executive summary:

The aim of this study was to determine potential effects on higher plants following deposition of Tridex 75 DG on the leaves and above-ground portions of non-target plants at the two to four leaf stage. The study was conducted to meet the requirements specified in the OECD Guideline 227 (July 2006) Terrestrial Plant Test: Vegetative Vigour Test. Onion, soya bean, oat, cabbage, carrot and tomato were evaluated for effects on vigour and phytotoxicity for 21 days after treatment. The test was conducted as a limit test at single test concentration of Tridex 75 DG, 1836 g product/ha. The study endpoints were survival (mortality), shoot height, fresh and dry shoot weight with an assessment of phytotoxicity or plant injury. All treatments were applied overhead to the plants at an application volume of 400 L/ha and rate of 1836 g Tridex 75 DG/ha. The plants were monitored for phytotoxic effects and mortality up to 21 DAT (days after treatment). After the final observation at 21 DAT, the shoot height, fresh and dry shoot weight were determined. Analytical determination of the concentration of the active ingredient, mancozeb, in the treatment solution was confirmed at between 80 and 120 % of the nominal concentration and therefore, the nominal rate of 1836 g Tridex 75 DG has been used. There was no mortality in the control or treatment group and no treatment related phytotoxic injury in onion, soya bean, oat, cabbage, carrot and tomato at the test concentration of 1836 g product/ha. There was no effect on the survival (mortality) of the treated plants for all the species (100% survival). The percentage difference from the control in shoot height for all species ranged from -5.3 to +5.0 % with the dry shoot weight ranging from -8.0 to +13.8%. The no observed effect rate (NOER) and the lowest observed effect rate (LOER) for the survival, shoot height, fresh weight and dry shoot weight for onion, soya bean, oat, cabbage, carrot and tomato were determined at 1836 g product/ha and >1836 g product/ha, respectively. This study has been deemed to have fulfilled the validity criteria stated in the guideline OECD 227 in that the germination for all the species was at least 70 % and the overall mean control plant survival was >90 % for all the species. The oat, onion, carrot and tomato control plants did display some mild visible signs of phytotoxic injury to individual plants but all replicates maintained good growth throughout the study. Environmental conditions for each particular plant species, control and treatments, were identical.

Description of key information

Short-term toxicity to terrestrial plants

In accordance with REACH Annex XI a short-term study does not need to be conducted because an appropriate long-term toxicity study on terrestrial organisms is available. Additional data on short-term toxicity is scientifically not necessary.

Long-term toxicity to terrestrial plants

In a study according to OECD TG 227 the 21-day ER50 and NOEC for the test item was determined to be > 1836 g product/ha and 1836 g product/ha (nominal), which corresponds to >1408 g a.s./ha and 1408 g a.s./ha, respectively. This value was re-calculated to be 1.872 mg/kg soil dw. The NOER (all effects) was assessed to be 1836 g product/ha (corresponding to 1408 g a.s./ha and 1.872 mg/kg soil dw, respectively).

Key value for chemical safety assessment

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

1.872 mg/kg soil dw

Additional information

Key study

TRIDEX 75 DG: Terrestrial plant test: vegetative vigour test (Collins 2017 (Doc. No. 851-005, cross reference to Risk Assessment Report according to Regulation (EU) No 1107/2009)

A Vegetative Vigour Test according to OECD Guideline 227 was carried out to determine potential effects on higher plants following deposition of Tridex 75 DG on the leaves and above-ground portions of non-target plants at the two to four leaf stage (Collins, 2017). Onion, soya bean, oat, cabbage, carrot and tomato were evaluated for effects on vigour and phytotoxicity for 21 days after treatment. The test was conducted as a limit test at one single test concentration of Tridex 75 DG, 1836 g product/ha. The study endpoints were survival (mortality), shoot height, fresh and dry shoot weight with an assessment of phytotoxicity or plant injury. All treatments were applied overhead to the plants at an application volume of 400 L/ha and rate of 1836 g Tridex 75 DG/ha. The plants were monitored for phytotoxic effects and mortality up to 21 DAT (days after treatment). After the final observation at 21 DAT, the shoot height, fresh and dry shoot weight were determined. Environmental conditions for each particular plant species, control and treatments, were identical. Analytical determination of the concentration of the active ingredient, mancozeb, in the treatment solution was confirmed at between 80 and 120 % of the nominal concentration and therefore, the nominal rate of 1836 g Tridex 75 DG has been used. There was no mortality in the control or treatment group and no treatment related phytotoxic injury in onion, soya bean, oat, cabbage, carrot and tomato at the test concentration of 1836 g product/ha. There was no effect on the survival (mortality) of the treated plants for all the species (100% survival). The percentage difference from the control in shoot height for all species ranged from -5.3 to +5.0 % with the dry shoot weight ranging from -8.0 to +13.8%. The no observed effect rate (NOER) and the lowest observed effect rate (LOER) for the survival, shoot height, fresh weight and dry shoot weight for onion, soya bean, oat, cabbage, carrot and tomato were determined at 1836 g product/ha and >1836 g product/ha, respectively. This study has been deemed to have fulfilled the validity criteria stated in the guideline OECD 227 as the germination for all the species was at least 70 % and the overall mean control plant survival was >90 % for all the species. The oat, onion, carrot and tomato control plants displayed some mild visible signs of phytotoxic injury to individual plants but all replicates maintained good growth throughout the study.