1H-1,2,4-Triazole-1-carboxamide, 4-amino-N-(1,1-dimethylethyl)-4,5-dihydro-3-(1-methylethyl)-5-oxo-

Toxicity to terrestrial plants

Administrative data

Endpoint:

toxicity to terrestrial plants: long-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

8 April to 6 May 1999

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study in accordance with generally accepted scientific standards and described in sufficient detail

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EPA OPP 123-1 (Seedling Emergence Tier II)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPP 123-1 (Vegetative Vigor Tier II)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

4-amino-N-tert-butyl-5-oxo-3-(propan-2-yl)-4,5-dihydro-1H-1,2,4-triazole-1-carboxamide

EC Number:

603-373-3

Cas Number:

129909-90-6

Molecular formula:

C10H19N5O2

IUPAC Name:

4-amino-N-tert-butyl-5-oxo-3-(propan-2-yl)-4,5-dihydro-1H-1,2,4-triazole-1-carboxamide

Details on test material:

- Name of test material (as cited in study report): MKH 3586 70WG
- Substance type: Formulated product
- Physical state: Tan granules
- Composition of test material, percentage of components: 71.1% amicarbazone
- Batch No.: 703-0090

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Analytical dose verification was carried out for the test solutions

Test substrate

Vehicle:

no

Details on preparation and application of test substrate:

- Method of application to soil surface (if used): Spray application
- Concentration of vehicle in test medium (stock solution and final test solution): Highest rate tested = 1.5 g product in 1

Test organisms

1

Species:

Allium cepa

Plant group:

Monocotyledonae (monocots)

2

Species:

Beta vulgaris

Plant group:

Dicotyledonae (dicots)

3

Species:

Brassica napus

Plant group:

Dicotyledonae (dicots)

4

Species:

Daucus carota

Plant group:

Dicotyledonae (dicots)

5

Species:

Lactuca sativa

Plant group:

Dicotyledonae (dicots)

6

Species:

Lolium perenne

Plant group:

Monocotyledonae (monocots)

7

Species:

Lycopersicon esculentum

Plant group:

Dicotyledonae (dicots)

8

Species:

Zea mays

Plant group:

Monocotyledonae (monocots)

9

Species:

Glycine max (G. soja)

Plant group:

Dicotyledonae (dicots)

10

Species:

Avena sativa

Plant group:

Monocotyledonae (monocots)

11

Species:

other: Fagopyrum esculentum

Plant group:

Monocotyledonae (monocots)

Study design

Test type:

seedling emergence toxicity / vegetative vigour test

Study type:

extended laboratory study

Substrate type:

natural soil

Limit test:

no

Total exposure duration:

21 d

Test conditions

Details on test conditions:

TEST SYSTEM
- Testing facility: Bayer Corporation
- Test container (type, material, size): 9 cm dimameter x 8 cm tall for canola, carrot, lettuce, oat, onion, perrennial ryegrass sugar beet and tomato, 10.5 cm diameter x 12 cm tall for buckwheat, corn and soyabean.
- No. of seeds per container: Seedling emergence: for corn and soyabean, 2 seeds per container; for the other species, 5 seeds per container
- No. of plants (retained after thinning): No thinning
- No. of replicates per treatment group: 4
- No. of replicates per control: 4
SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Geographic location: Johnson County., USA
- Pesticide use history at the collection site: Not stated
- Collection procedures: Not stated
- Sampling depth (cm): Not stated
- Soil texture (if natural soil)
- % sand: 60
- % silt: 24
- % clay: 16
- Soil taxonomic classification: Sandy loam
- Soil classification system: Not stated
- Composition (if artificial substrate): NA
- Organic carbon (%): 2.5
- Maximum water holding capacity (in % dry weigth): Not stated
- CEC: 12.7

GROWTH CONDITIONS
- Photoperiod: At least 12 hours
- Light source: Natural light suplemented with sodium vapour lamps
- Light intensity and quality:
- Day/night temperatures:
- Relative humidity (%):
- Wind velocity:
- Air exchange rate:
- Watering regime and schedules:
- Water source/type:
- Volume applied:
- Interval of applications:
- Method of application:
- Any pest control method/fertilization (if used):

ACCLIMATION PERIOD:

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :

- Phytotoxicity rating system (if used):

VEHICLE CONTROL PERFORMED: yes/no

TEST CONCENTRATIONS
- Spacing factor for test concentrations:
- Justification for using less concentrations than requested by guideline:
- Range finding study
- Test concentrations:
- Results used to determine the conditions for the definitive study:

Nominal and measured concentrations:

Application rates: 1, 2, 4, 8, 16, 31, 63, 125 and 250 g a.i./ha

Results and discussion

Any other information on results incl. tables

Table 1: NOEC and ER50 values for vegetative vigour and seedling emergence assessments

Species	Vegetative vigour		Seedling emergence
	NOEC        (g a.i./ha)	ER50          (g a.i./ha)	NOEC        (g a.i./ha)	ER50          (g a.i./ha)
Fagopyrum esculentum(buckwheat)^a	2	8.8	-	-
Brassica napus(oilseed rape)^a	16	>63	31	79.5
Daucus carota(carrot)^bc	-	-	31	260
Lactuca sativa(lettuce)^a	4	12.2	63	131
Glycine max(soya bean)^a	16	54.7	250	>250
Beta vulgaris(sugar beet)^bc	2	14.6	16	74.1
Lycopersicon esculentum(tomato)^a	8	29.5	63	>250
Zea mays(maize)^a	63	>250	250	>250
Avena sativa(oat)^bd	63	>250	>250	>250
Alium cepa(onion)^a	16	56.6	146	>250
Lolium perenne(perennial ryegrass)^a	63	235	250	>250

^a= endpoint based on dry weight

^b= endpoint based on dry weight for vegetative vigour

^c= endpoint based on survival for seedling emergence

^d= endpoint based on shoot height for seedling emergence

Applicant's summary and conclusion

Conclusions:

Seedling emergence test: There were no statistically significant adverse effects on persent seedling emergence as compared to the controls for any species tested. Sugar beet was the most sensitive species tested with an ER50 value of 74.1 g a.i./ha

Vegetative vigour test: Buckwheat was the most sensitive species tested with an ER50 value of 8.8 g a.i./ha

Executive summary:

In a non-target plant study with amicarbazone, lowest ER50 values of 74.1 g a.i./ha (sugar beet) and 8.8 g a.i./ha (buckwheat) were obtained for seedling emergence and vegetative vigour, respectively.