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Administrative data

Endpoint:
toxicity to terrestrial plants: short-term
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study quite well documented, not performed according to actual standardised guideline, but method scientifically sounds.

Data source

Reference
Reference Type:
publication
Title:
A rapid seedling bioassay for the study of allelopathy
Author:
Shilling D & Yoshikawa F
Year:
1987
Bibliographic source:
American Chemical Society (Ed.), chapter 31: 334-342

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Phytotoxic activity of 26 compounds (including vanillin and ethylvanillin) was determined by measuring different growth parameters using two test species: Echinochloa crusgalli L. Beauvois (barnyardgrass, a monocot) and Sesbania exaltata Raf. Cory. (hemp sesbania, a dicot).
Growth parameters followed were :
•Shoot length (i.e. coleoptile and leaf tissue for barnyardgrass and hypocotyl tissue for hemp sesbania)
•Root length
•Total fresh weight
Seeds were placed on a filter paper, in jars, with the test substance and MES buffer. Seeds were let germinated at 25°C with a 12h photoperiod and harvested after 60h and 72h for barnyardgrass and hemp sesbania respectively.
GLP compliance:
not specified

Test material

Constituent 1
Chemical structure
Reference substance name:
3-ethoxy-4-hydroxybenzaldehyde
EC Number:
204-464-7
EC Name:
3-ethoxy-4-hydroxybenzaldehyde
Cas Number:
121-32-4
Molecular formula:
C9H10O3
IUPAC Name:
3-ethoxy-4-hydroxybenzaldehyde
Details on test material:
no data

Sampling and analysis

Analytical monitoring:
not required

Test substrate

Vehicle:
yes
Details on preparation and application of test substrate:
Ethylvanillin was dissolved in acetone and the 2 mM solution was placed in 60 jars with Whatman #1 filter paper. After the solvent was evaporated, either 0.22 g (60 seeds) of barnyardgrass or 0.40 g (30 seeds) of hemp sesbania were placed in jars. 3 mL and 3.5 mL of 15 mM MES buffer [2-morpholinoethanesulfonic acid] adjusted to pH 6.0 was added for barnyardgrass and hemp sesbania respectively.

- Controls: acetone-treated filter paper alone
- Chemical name of vehicle: acetone
- Concentration of vehicle in test medium (stock solution and final test solution): no data
- Evaporation of vehicle before use: yes

Test organisms

open allclose all
Species:
other: Echinochloa crusgalli L. Beauvois
Plant group:
Monocotyledonae (monocots)
Details on test organisms:
Common name: barnyardgrass
Species:
other: Sesbania exaltata Raf. Cory.
Plant group:
Dicotyledonae (dicots)
Details on test organisms:
Common name: hemp sesbania

Study design

Test type:
seed germination/root elongation toxicity test
Study type:
laboratory study
Substrate type:
filter paper
Total exposure duration:
72 h
Remarks:
Barnyardgrass harvested after 72h of exposition and hemp sesbania after 60h

Test conditions

Test temperature:
25°C
pH:
6.0
Details on test conditions:
seed germination/root elongation toxicity test: rapid seedling bioassay.

TEST SYSTEM
- Test container (type, material, size): 60 mL jars
- Method of seeding: seeds were put upon the paper filter
- No. of seeds per container: 0.22 g (60 seeds) of barnyardgrass // 0.40 g (30 seeds) of hemp sesbania
- No. of replicates per treatment group: no data
- No. of replicates per control: no data
- No. of replicates per vehicle control: no data

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
NUTRIENT MEDIUM (if used)
- Description: MES buffer [2-morpholinoethanesulfonic acid]

GROWTH CONDITIONS
- Photoperiod: 12h
- Light source: no data
- Light intensity and quality: no data
- Day/night temperatures: 25°C
- Water source/type: batch culture
- Volume applied: 3 mL (barnyardgrass) and 3.5 mL (hemp sesbania)
- Method of application: no data

ACCLIMATION PERIOD: no data

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : no data

VEHICLE CONTROL PERFORMED: no data
Nominal and measured concentrations:
2mM (nominal)
Reference substance (positive control):
yes
Remarks:
alpha-phenyllactic acid and p-ethoxybenzoic acid

Results and discussion

Effect concentrations
Species:
other: Echinochloa crusgalli L. Beauvois (barnyardgrass)
Duration:
72 h
Dose descriptor:
other: 4 growth parameters : shoot length / root length / total fresh weight / Predicted shoot plus root fresh weight
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth
Remarks on result:
other: Only the total fresh weight is significantly different from the control at 2mM.
Details on results:
SEED GERMINATION
- Percent seed germination versus control plants:
barnyardgrass: 93%
hemp sesbania: 89%

see different growth parameters in table 1
Results with reference substance (positive control):
see table 1
- Results with reference substance valid? yes

Any other information on results incl. tables

Table 1:  Percentage of inhibition of the compounds on four growth parameters of banyardgrass and hemp sesbania.

Chemical

Barnyardgrass

Hemp sesbania

Shoot lenght

Root lenght

Total fresh weight

Shoot lenght

Root lenght

Total fresh weight

a-phenyllactic acid

(positive control)

12

57*

22*

13*

56*

22*

p-ethoxybenzoic acid

(positive control)

18*

84*

29*

22*

66*

27*

Ethyl vanillin

15

17

15*

0

0

0

Values followed by an asterisk are significantly different from the control at the 0.05 level according to general linear model procedure.

Applicant's summary and conclusion

Validity criteria fulfilled:
not applicable
Conclusions:
In the tested conditions, no or slight inhibition on plant growth factor was observed (shoot length / root length / total fresh weight)
Executive summary:

In a study (Shilling et al., 1987), the toxicity to terresterial plants was evaluated. The observations were the following:

Hemp sesbania: 0% of inhibition is observed for all growth parameter followed when seeds are exposed to ethyl vanillin at 2 mM during 60h. In the test conditions, Ethylvanillin as no phytotoxic effect on this species.

Barnyardgrass: Only a slight inhibition (between 15 and 19%) on growth parameters has been observed after 72h of exposition of ethylvanillin at 2 mM. But it is significantly different from the controls only for 1 of the 3 growth parameters (total fresh weight) but not for the most sensitive one the root length.

Only the total fresh weight is significantly different from the control. The two other parameters measured (root and shoot lengths) are not significantly different from the control. It is may be due to the difficulty on measuring these parameters. But authors also indicate that root growth was the most sensitive parameter and total fresh weight even if easier to measure is less sensitive. As Ethyl vanillin showed an effect only on the less sensitive growth parameter, and not on the two other more sensitive ones, it is therefore reasonnable to assess that Ethyl vanillin as no phytotoxic effect on this species in the described conditions.

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