N-cyclopropyl-1,3,5-triazine-2,4,6-triamine

Toxicity to terrestrial plants

Administrative data

Endpoint:

toxicity to terrestrial plants: long-term

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1999/12/21 to 2000/01/11

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Standardised treatment protocols were in place at the time the data were collected and the data presented are believed to be scientifically valid.

GLP compliance:

no

Remarks:

The study does not meet all the requirements of GLP

Test material

Test material information

Constituent 1

Reference substance name:

N-cyclopropyl-1,3,5-triazine-2,4,6-triamine

EC Number:

266-257-8

EC Name:

N-cyclopropyl-1,3,5-triazine-2,4,6-triamine

Cas Number:

66215-27-8

Molecular formula:

C6H10N6

IUPAC Name:

N2-cyclopropyl-1,3,5-triazine-2,4,6-triamine

Sampling and analysis

Analytical monitoring:

no

Details on sampling:

Visual phototoxicity ratings were recorded 21 days after the application of the test item for seedling emergence. For vegetative vigour, visual phototoxicity ratings were recorded 14 days after the application of the test item. Evaluation of phytotoxicity was by visual observation that used a rating scale ranging from 1 (complete destruction or no emergence of the plants) to 9 (no effect, similar to untreated). Individual scoring was always as compared to the untreated control.

Test substrate

Vehicle:

no

Details on preparation and application of test substrate:

In both test systems, the test treatments were applied using a laboratory sprayer at 6 rates (12.5, 25, 50, 100, 200 and 400g cyromazine/ha) and compared to untreated controls. All treatments were applied in a volume equivalent to 500L/ha.

The following stock solutions were prepared just before treatment application with the test item:
Stock solution: Amount of substance + diluted with deionized water to
400g/ha cyromazine : 0.4g (substance) + 50mL
200g/ha cyromazine : 25mL of above stock + 50mL
100g/ha cyromazine : 25mL of above stock + 50mL
50g/ha cyromazine : 25mL of above stock + 50mL
25g/ha cyromazine : 25mL of above stock + 50mL
12.5g/ha cyromazine : 25mL of above stock + 50mL

Test organisms

1

Species:

Glycine max (G. soja)

Plant group:

Dicotyledonae (dicots)

2

Species:

Brassica napus

Plant group:

Dicotyledonae (dicots)

3

Species:

Beta vulgaris

Plant group:

Dicotyledonae (dicots)

4

Species:

Allium cepa

Plant group:

Monocotyledonae (monocots)

5

Species:

other: Avena fatua L

Plant group:

Monocotyledonae (monocots)

6

Species:

Zea mays

Plant group:

Monocotyledonae (monocots)

Study design

Test type:

seedling emergence toxicity / vegetative vigour test

Study type:

laboratory study

Substrate type:

artificial soil

Remarks:

26% clay, 34% silt and 40% sand with a pH of 7 5 and containing 2 6% organic matter)

Limit test:

no

Total exposure duration:

21 d

Remarks:

For seedling emergence: visual assessments of phytotoxicity were made 21 days after application.
For vegetative vigor test: visual assessments of phytotoxicity were made 14 days after the application of the test treatments.

Test conditions

Test temperature:

The warm season plants were maintained at 18-20°C during the night and maintained at 25-27°C during the day.
The cool season plants were maintained at temperature which ranged from 15-17°C during the night and 20-22°C during the day.

pH:

7.5

Moisture:

40-60%

Details on test conditions:

Seedling emergence: The seeds were planted in a mineral soil (26% clay, 34% silt and 40% sand with a pH of 7 5 and containing 2 6% organic matter) in 10cm deep plastic trays. Within 24-hours of watering the seeds in, the test substance treatments were applied by spray application directly to the soil surface, visual assessments of phytotoxicity were made 21 days after application.

Vegetative vigour: The plants were grown (in the mineral soil as described above) to the 2-4 leaf stage before being treated via foliar application. Treatments were applied 14 days after emergence for the warm season plants and seventeen days after emergence for the cool season plants. Visual assessments of phytotoxicity were made 14 days after the application of the test treatments.

Physical parameters monitored: The warm season plants were maintained at 18-20°C during the night and maintained at 25-27°C during the day. Relative humidity ranged from 40-60% and a minimum light intensity of 10,000 Lux was maintained for the 14-hour photoperiod. The conditions for the cool season plants was the same as for the warm season plants with the exception of temperature which ranged from 15-17°C during the night and 20-22°C during the day.

Nominal and measured concentrations:

Nominal concentrations: 12.5, 25, 50, 100, 200 and 400 g cyromazine/ha

Results and discussion

Details on results:

Symptoms of toxicity: In assessing the effect of the test treatment visual observations were used to generate a 1 to 9 rating scale. One equates to complete destruction of the plants and nine equates to no effect (identical to the control).

Seedling emergence: Cyromazine had a slight effect on the emergence of Zea mays at 400 g/ha, however when applied to Glycine max a very slight effect on seedling emergence was noted at concentrations as low as 50 g cyromazine/ha. However, in both species the effect was slight.

Vegetative vigour: Cyromazine had a very slight effect on the vegetative vigour of Zea mays when applied at 400 and 200 g/ha. However the effect is very slight and is restricted to this single test species.

Any other information on results incl. tables

Table 1

 

Phytotoxic effect of Glycine observed on seedling emergence of six plant species

Application rate (g/ha cyromazine formulation)	Brassica napusn	Avena fatua	Beta vulgaris	Zea mays	Glycine max	Allium cepa
400	9	9	9	7 5	7 5	9
200	9	9	9	9	7 5	9
100	9	9	9	9	7 5	9
50	9	9	9	9	8 5	9
25	9	9	9	9	9	9
12 5	9	9	9	9	9	9

 

Rating Scale from 1-9: 1 = no emergence or complete destruction of above ground parts and 9 = no visual damage Data are given as the average of two replicates

 

Table 2

 

Effects of cyromazine formulation observed on vegetative vigour of six plant species

 

Application rate (g/ha cyromazine formulation)	Brassica napus	Avena fatua	Beta vulgaris	Zea mays	Glycine max	Allium cepa
400	9	9	9	8 5	9	9
200	9	9	9	8 5	9	9
100	9	9	9	9	9	9
50	9	9	9	9	9	9
25	9	9	9	9	9	9
12 5	9	9	9	9	9	9

Rating Scale from 1-9: 1 = no emergence or complete destruction of above ground parts and 9 = no visual damage Data are given as the average of two replicates

 

Applicant's summary and conclusion

Validity criteria fulfilled:

not applicable

Conclusions:

The seedling emergence of 4 species was unaffected by treatment with cyromazine at 400 g/ha only slight signs of phytotoxicity were noted in Zea mays and Glycine max. The vegetative vigour of 5 species was unaffected by cyromaizne at 400 g/ha and only very slight signs of phytotoxicity were noted with Zea mays.

Executive summary:

The effect of cyromazine on a representative range of economically important plant species was investigated in a laboratory study. The study had two distinct components firstly, to investigate the effect of the test substance on seedling emergence and secondly to study any effect the test substance treatments had on vegetative vigour. In both test systems the test treatments were applied using a laboratory sprayer at 6 rates (12.5, 25, 50, 100, 200 and 400g cyromazine/ha) and compared to untreated controls. All treatments were applied in a volume equivalent to 500L/ha.

 

The seedling emergence of 4 species was unaffected by treatment with cyromazine at 400 g/ha only slight signs of phytotoxicity were noted in Zea mays and Glycine max. The vegetative vigour of 5 species was unaffected by cyromaizne at 400 g/ha and only very slight signs of phytotoxicity were noted with Zea mays.