Chlorpyrifos

Toxicity to terrestrial plants

Link to relevant study record(s)

Reference

Reference 1

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:

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

Principles of method if other than guideline:

The objective of this study was to evaluate the pre-emergence phytotoxicity of three Dursban
(chlorpyrifos-ethyl) formulations applied at rates ranging from 353.92 to 2400 g ai/ha to a
range of weed and crop species. Applications were made pre-emergence using a track sprayer fitted with a Tee Jet 8002E flat fan nozzle, calibrated to deliver 192.9 l/ha. A total of 6 crop species and 9 weed species from 7 plant families were tested in this study. The species evaluated represented members of the Gramineae, Leguminosae, Chenopdiaceae. Euphorbiaceae, Convolvulaceae, Asteraceae and Malvaceae families.

GLP compliance:

no

Specific details on test material used for the study:

GF-1668 containing 200 g ai/L Chlorpyrifos - ethyl. Formulation type was CS.
EF-1315 containing 750 g ai/L Chlorpyrifos - ethyl. Formulation type was WG.
EF-1551 containing 480 g ai/L Chlorpyrifos - ethyl. Formulation type was EC.

Analytical monitoring:

no

Vehicle:

yes

Remarks:

city water

Details on preparation and application of test substrate:

Spray solutions were prepared by diluting the aliquots of the formulations in city water. Applications were made pre-emergence using a mechanised track sprayer fitted with a flat fan nozzle 8002E, reservoir pressure 276 kPa calibrated to deliver 1921l/ha.

Species:

other: C. album

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

Quantity of seed: 1 pinch

Species:

Beta vulgaris

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

Quantity of seed: 10 seeds

Species:

other: A. myosuroides

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

Quantity of seed: 20-30 seeds

Species:

Zea mays

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

Quantity of seed: 2 seeds

Species:

other: A. theophasti

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

Quantity of seed: 8-10 seeds

Species:

other: D. sanguinalis

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

Quantity of seed: 8-10 seeds

Species:

Glycine max (G. soja)

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

Quantity of seed: 3 seeds

Species:

other: A. fatua

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

Quantity of seed: 8-10 seeds

Species:

Helianthus annuus

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

Quantity of seed: 3 seeds

Species:

other: I. hederacea

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

Quantity of seed: 3 seeds

Species:

Triticum aestivum

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

Quantity of seed: 10 seeds

Species:

other: E. heterophylla

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

Quantity of seed: 10-15 seeds

Species:

other: E crus-galli

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

Quantity of seed: 10-15 seeds

Species:

Sorghum bicolor

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

Quantity of seed: 8-10 seeds

Species:

Oryza sativa

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

Quantity of seed: 10 seeds

Test type:

seedling emergence toxicity test

Study type:

laboratory study

Substrate type:

other: mineral: grit mix (80:20)

Limit test:

no

Total exposure duration:

1 d

Post exposure observation period:

7, 14, and 21 days post-application

Test temperature:

28°C

Details on test conditions:

Humidity: 43%
14 h photoperiod
Post application pots were watered lightly overhead 2-3 times a day with Hoaglands fertilizer.
Three or four plants species were sown per pot. Three replicate pots were used per treatment and species combination.

Nominal and measured concentrations:

Untreated: 0 g a.i./ha
GF-1668: 377.52, 1200, 2400 g a.i./ha
EF-1315: 377.52, 1200, 2400 g a.i./ha
EF-1551: 377.52, 1200, 2400 g a.i./ha

Reference substance (positive control):

no

Key result

Species:

other: all species tested

Duration:

21 d

Dose descriptor:

other: phytotoxicity

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Remarks on result:

other: GF-1668 did not reduce emergence of any of the test species by 50%. Visual injury (necrotic spotting) was only observed in one species and was at 12% (significantly below the 50% required to trigger a Tier II test)

Key result

Species:

other: all species tested

Duration:

21 d

Dose descriptor:

other: phytotoxicity

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Remarks on result:

other: EF-1351 did not reduce emergence of any of the test species by 50%. No visual injury was observed.

Key result

Species:

other: all species tested

Duration:

21 d

Dose descriptor:

other: phytotoxicity

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Remarks on result:

other: EF-1551 did not reduce emergence of any of the test species by 50%. Visual injury (necrotic spotting) was only observed in one species and was at 5% (significantly below the 50% required to trigger a Tier II test)

Details on results:

GF-1668
Crop species: Twenty one days after application >=78 % emergence was recorded for all species treated with GF-1668 applied at rates ranging from 377.5 to 2400 g ai/ha. While there was some variability in the data, it was not always treatment related and it is thought to be the result of some other factor such as uneven planting depth or watering.

No visual injury was observed on any of the six crop species tested, following pre-emergence applications of GF-1668, at rates ranging from 377.5 to 2400 g ai/ha. Therefore preemergence applications of GF-1668 are considered selective to BEA VA, ZEAMX, GLXMA, HELAN, TRZAS and ORYSA.

Grass weed species: Twenty one days after application >= 81 % emergence was recorded for all species following pre-emergence applications of GF-1668, at rates ranging from 337.5 to 2400 g ai/ha. No visual injury was observed on any of the five grass weed species tested following preemergence applications of GF-1668 at rates ranging from 377.5 to 2400 g ai/ha. Therefore. pre-emergence applications of GF-1668 are considered selective to AVEFA, ALOMY,
DIGSA, ECHCG and SORBI.

Broad leaf weed species: Twenty one days after application >- 70 % emergence was recorded for CHEAL ABUTH, IPOHE and EPHHL following pre-emergence applications of GF-1668 at rates ranging from 337.5 to 2400 g ai/ha. While there was some variability in the data for these species. this variation was not always treatment related and it is thought to be the result of some other factor such as uneven watering or planting depth.

No visual injury was observed on CHEAL, ABUTH, and IPOHE following pre-emergence applications ofGF-1668 at rates ranging from 377.5 to 2400 g ai/ha. Slight injury (12 %) was observed on EPHHL following pre-emergence applications of GF-1668 applied at 2400 g ai/ha the symptom of which was necrotic spotting.

EF-1315
Crop species: Twenty-one days after application ~ 89 % emergence was recorded for BEA VA, ZEAMX,
TRZAS and ORYSA following pre-emergence application of EF-1315 at rates ranging from 337.5 to 2400 g ai/ha. While there was some variability in the data for these species, this variation was not always treatment related and it is thought to be the result of some other factor such as uneven watering or planting depth. Seven days after application 134 % and 100 % emergence was record for GLXMA and
HELAN respectively. However, by the 21 day assessment the number of plants per pot had declined to 67 and 57 % respectively. This reduction in plant numbers was a result of a soil pathogen, which resulted in the damping off of seedling in some of the replicates. The symptoms of damping off were observed across the entire test.

No visual injury was observed on any of the six crop species following application of EF- 1315 applied at rates ranging from 377.5 to 2400 g ai/ha. Therefore, pre-emergence applications of EF-1315 are considered selective to BEAV A, ZEAMX, GLXMA, HELAN. TRZAS and ORYSA.

Grass weed species: Twenty one days after application ~ 93 % emergence was recorded for all species treated with EF-1315 applied at 2400 g ai/ha.

No visual injury was observed on any of the five grass weed species following pre-emergence applications of EF-1315 at rates ranging from 377.5 to 2400 g ai/ha. Therefore. preemergence applications of EF-1315 are considered selective to AVEFA, ALOMY, DIGSA, ECHCG and SORBI.

Broad leaf weed species: Twenty one days after application 2 77 % emergence was recorded for CHEAL, ABUTH, IPOHE and EPHHL following application of EF-1315 at rates ranging from 337.5 to 2400 g ai/ha. While there was some variability in the data for these species, this variation was not always treatment related and it is thought to be the result of some other factor such as uneven watering or planting depth.

No visual injury was observed on CHEAL, ABUTH, IPOHE and EPHHL following preemergence applications of EF-1315 applied at rates ranging from 377.5 to 2400 g ai/ha. Therefore, pre-emergence applications of EF-1315 are considered selective to CHEAL, ABUTH, IPHOE and EPHHL

EF-1551
Crop species: Twenty-one days after application ~ 100 %mergence was recorded for all species following
application of EF-1551 at 2400 g ai/ha. While there was some variability in the data for these species, this variation was not always treatment related and it is thought to be the result of some other factor such as uneven watering or planting depth.

No visual injury was observed on any of the six crop species following pre-emergence applications of EF-1551 applied at rates ranging from 377.5 to 2400 g ai/ha. Therefore, preemergence applications of EF-1551 are considered safe to BEAVA, ZEAMX, GLXMA, HELAN, TRZAS and ORYSA.

Grass weed species: Twenty-one days after application 100 % emergence was recorded for all species treated with EF-1551 applied at rates ranging from 337.5 to 2400 g ai/ha.

No visual injury was observed on any of the five grass weed species following pre-emergence applications of EF-1551 applied at rates ranging from 377.5 to 2400 g ai/ha. Therefore, preemergence applications of EF-1551 are considered safe to AVEFA, ALOMY, DIGSA, ECHCG and SORBI.

Broad leaf weed species: Twenty-one days after application >= 85 % emergence was recorded for CHEAL, ABUTH, IPOHE and EPHHL following application of EF-1551 at rates ranging 337.5 to 2400 g ai/ha. While there was some variability in the data for these species, this variation was not always treatment related and it is thought to be the result of some other factor such as uneven watering or planting depth.

No visual injury was observed on CHEAL, ABUTH and IPOHE following pre-emergence applications of EF-1551 applied at rates ranging from 377.5 to 2400 g ai/ha. Applied at 2400 g ai/ha EF-1551 resulted in slight injury (5 %) to EPHHL the symptom of which was necrotic spotting.

GF-1668:

Across the fifteen test species evaluated in this pre-emergence herbicide screen there was a degree of variability in the emergence data. With lower rates of emergence not always treatment related, it is thought that this variability/reduction in emergence is the result of some other factor such as uneven planting depth or watering. At the final assessment timing (21 daa) Gf-1668 applied pre-emergence at a rates ranging from 377.5 of 2400 g ai/ha, did not reduced the emergence of any of the test species by 50%.Visual injury was only observed at the 2400 g ai/ha rate of GF-1668, on one of the fifteen test

species. The symptom of visual injury was necrotic spotting and was only observed on EPHHL 14 and 21 days after application. The maximum score for visual injury to EPHHL was 12%significantly below the 50%required to trigger a Tier II test (Guidance Document on Terrestrial Ecotoxicolgy under Council Directive 91/414/EEC).

EF-1315:

Across the fifteen test species evaluated in this pre-emergence herbicide screen there was a degree of variability in the emergence data. With lower rates of emergence not always treatment related, it is thought that this variability/in emergence is the result of some other factor such as uneven planting depth or watering. In addition, there was evidence of damping off (symptom of soil pathogen) in species such as GLXMA and HELAN. Twenty-one days after application GF-1351 applied at 2400 g ai/ha did not reduce the emergence of any of the test species by 50 %. No visual injury was observed on any of the fifteen test species following pre-emergence application of EF-1315 applied at rates up to and including 2400 g ai/ha.

EF-1551:

Across the fifteen test species evaluated in this pre-emergence herbicide screen there was a degree of variability in the emergence data. With lower rates of emergence not always treatment related, it is thought that this variability/reduction in emergence is the result of some other factor such as uneven planting depth or watering. Twenty-one days after application GF-1551 applied at 2400 g ai/ha did not reduced the emergence of any of the test species by 50%.Visual injury was only observed at the 2400 g ai/ha rate of GF-1551, on one of the fifteen test species. The symptom of visual injury was necrotic spotting and was only observed on EPHHL 14 and 21 days after application. The maximum score for visual injury to EPHHL was 5%significantly below the 50%required to trigger a Tier 11 test (Guidance Document on Terrestrial Ecotoxicolgy under Council Directive 911414/EEC).

Validity criteria fulfilled:

yes

Conclusions:

None of the three Dursban (GF-1668, EF-1315 and EF-1551) formulations tested reduced the emergence by 50% or resulted in 50% injury to any of the following species: A. myosuroides, A. fatua, E. Crus-galli, D. sanguinalis, S. bicolor,O. sativa, T. aestivum.Z. mays.G. max, B. vulgaris,C. album, I. hederaeea, E. heterophylla, A. theophastic,and H. annus.

Executive summary:

The objective of this study was to evaluate the pre-emergence phytotoxicity of three Dursban

(chlorpyrifos-ethyl) formulations applied at rates ranging from 353.92to2400 g ai/ha to a range of weed and crop species. Applications were made pre-emergence using a track sprayer fitted with a Tee Jet 8002E flat fan nozzle, calibrated to deliver 192.9 l/ha. A total of 6 crop species and 9 weed species from 7 plant families were tested in this study. The species evaluated represented members of the Gramineae, Leguminosae, Chenopdiaceae. Euphorbiaceae, Convolvulaceae, Asteraceae and Malvaceae families.

 

Visual injury was only observed on one of the fifteen test species evaluated, with two out of the three chlorpyrifos formulations screened. Injury was to E heterophylla was only observed with GF-1668 and EF-166l. The maximum level of injury observed on this species during the course of the study was 12 %.

None of the three Dursban (GF-1668, EF-1315 and EF-1551) formulations tested reduced the emergence by 50% or resulted in 50% injury to any of the following species: A. myosuroides, A. fatua, E. Crus-galli, D. sanguinalis, S. bicolor,O. sativa, T. aestivum.Z. mays.G. max, B. vulgaris,C. album, I. hederaeea, E. heterophylla, A. theophastic,and H. annus.

Reference 2

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:

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

Principles of method if other than guideline:

The objective of this study was to evaluate the post-emergence phytotoxicity of three Dursban
(chlorpyrifos-ethyl) formulations to a range of weed and crop species. Applications were made post-emergence using a track sprayer fitted with a Tee Jet 8002E flat fan nozzle, calibrated to deliver 185 l/ha.
A total of 8 crop species and 16 weed species from 15 plant families were tested in this study. The species evaluated represented members of the Gramineae, Leguminosae, Brassicaceae, Amaranthaceae, Chenopdiaceae, Euphorbiaceae, Convolvulaceae, Asteraceae and Malvaceae families.

GLP compliance:

no

Specific details on test material used for the study:

-1668 containing 200 g ai/L Chlorpyrifos - ethyl. Formulation type was CS.
EF-1315 containing 750 g ai/L Chlorpyrifos - ethyl. Formulation type was WG.
EF-1551 containing 480 g ai/L Chlorpyrifos - ethyl. Formulation type was EC.

Analytical monitoring:

no

Vehicle:

yes

Remarks:

tap water

Details on preparation and application of test substrate:

Spray solutions were made by first creating a concentrated stock solution of the formulation in tap water. Final spray solutions were made by adding specified aliquots of the concentrated stock solution in tap water to make up a 12 ml final spray solution. Applications were made post-emergence using a mechanised track sprayer fitted with a flat fan nozzle, reservoir pressure 276 kPa calibrated to deliver 185.41 /ha.

Species:

other: Avena fatua

Plant group:

Monocotyledonae (monocots)

Species:

other: Alopecurus myosuroides

Plant group:

Monocotyledonae (monocots)

Species:

other: Echinochloa crus- galli

Plant group:

Monocotyledonae (monocots)

Species:

other: Setaria faberii

Plant group:

Monocotyledonae (monocots)

Species:

other: Digitaria sanguinalis

Plant group:

Monocotyledonae (monocots)

Species:

Sorghum bicolor

Plant group:

Monocotyledonae (monocots)

Species:

Oryza sativa

Plant group:

Monocotyledonae (monocots)

Species:

Triticum aestivum

Plant group:

Monocotyledonae (monocots)

Species:

Zea mays

Plant group:

Monocotyledonae (monocots)

Species:

Glycine max (G. soja)

Plant group:

Dicotyledonae (dicots)

Species:

Brassica napus

Plant group:

Dicotyledonae (dicots)

Species:

other: Abutilon theophasti

Plant group:

Monocotyledonae (monocots)

Species:

other: Chenopodium album

Plant group:

Dicotyledonae (dicots)

Species:

other: Ipomoea hederacea

Plant group:

Monocotyledonae (monocots)

Species:

other: Euphorbia heterophylla

Plant group:

Dicotyledonae (dicots)

Species:

other: Amaranthus retroflexus

Plant group:

Dicotyledonae (dicots)

Species:

Helianthus annuus

Plant group:

Dicotyledonae (dicots)

Species:

other: Stellaria media

Plant group:

Dicotyledonae (dicots)

Species:

other: Cirisum arvensis

Plant group:

Dicotyledonae (dicots)

Species:

other: Polygonum convolvulus

Plant group:

Dicotyledonae (dicots)

Species:

other: Viola tricolor

Plant group:

Dicotyledonae (dicots)

Test type:

vegetative vigour test

Study type:

laboratory study

Substrate type:

other: metro mix 360

Limit test:

no

Total exposure duration:

1 d

Post exposure observation period:

7, 14, and 21 days

Test temperature:

22°C

Details on test conditions:

Seed was sown, at a depth of 1.3 em in 10.1 em (4 inch) square pots filled with metro mix 360. Three or four plants species were sown per pot as described. Three replicate pots were used per treatment and species combination. Applications were made post-emergence.

humidity 65 % and a 16 h photoperiod

Nominal and measured concentrations:

Untreated: 0 g a.i./ha
GF-1668: 377.52, 1200, 2400 g a.i./ha
EF-1315: 377.52, 1200, 2400 g a.i./ha
EF-1551: 377.52, 1200, 2400 g a.i./ha

Reference substance (positive control):

no

Key result

Species:

other: all species tested

Duration:

21 d

Dose descriptor:

other: visual injury

Conc. based on:

test mat.

Basis for effect:

phytotoxicity

Remarks on result:

other: GF-1668: no visual injury of any test species by 50%. EPHHL was the most sensitive species with a maximum score of 20% at 7 days post application. Visual injury was transient and only 5% injury was recorded 21 post application.

Key result

Species:

other: all species tested

Duration:

21 d

Dose descriptor:

other: visual injury

Conc. based on:

test mat.

Basis for effect:

phytotoxicity

Remarks on result:

other: EF-1315: no visual injury of any of the test species by 50%. EPHHL was the most sensitive species with a maximum score of 10% at 7 days post application. Visual injury was transient and only 5% injury was recorded 21 post application.

Key result

Species:

other: all species tested

Duration:

21 d

Dose descriptor:

other: visual injury

Conc. based on:

test mat.

Basis for effect:

phytotoxicity

Remarks on result:

other: EF-1551: no visual injury of any test species by 50%. CIRAR was the most sensitive species with a maximum score of 17% at 7 days post application. Visual injury was transient and only 10% injury was recorded 21 post application.

Details on results:

GF-1668
Crop species: GF-1668 applied at rates ranging from 337.5 to 2400 g ai/ha was completely selective to ZEAMX, HELAN, TRZAS and ORYSA, with no visual injury recorded, during the 21 day test period. Slight (~ 10 %) transient injury was recorded on GLXMA and BRSNN following application of the 2400 g ai/ha rate of GF-1668. In both cases plants had fully recovered by the 21 day assessment. Symptoms of visual injury were necrotic spotting, tip bum and leaf cupping, which were all observed on the leaves present at the time of application. All subsequent new growth was healthy.

Grass weed species: GF-1668 applied at rates ranging from 337.5 to 2400 g ai/ha was completely selective to AVEFA, ALOMY, SETFA, DIGSA, ECHCG and SORBI with no visual injury recorded,
during the 21 day test period.

Broad leaf weed species: GF-1668 applied at rates ranging from 337.5 to 2400 g ai/ha was completely selective to CHEAL, VIOTR and AMARE, with no visual injury recorded, during the 21 day test period. Transient injury (≤20 %) was recorded on STEME, PLOCO, CIRAR, ABUTH, IPOHE and EPHHL following application of the 2400 g ai/ha rate of GF-1668. Slight injury (5 %) was also observed on CIRAR with the 1200 g ai/ha rate of GF-1668. In all cases plants had either fully recovered or were recovering by the 21 day assessment. Symptoms of visual injurywere necrotic spotting, tip burn and leaf cupping, which were all observed on the leaves present at the time of application. All subsequent new growth was healthy.

EF-1315
Crop species: EF-1315 applied post -emergence at rates ranging from 337.5 to 2400 g ai/ha was completely selective to ZEAMX, GLXMA, HELAN, BRSNN, TRZAS and ORYSA, with no visual injury recorded, during the 21 day test period.

Grass weed species: EF-1315 applied post - emergence at rates ranging from 337.5 to 2400 g ai/ha was completely selective to AVEFA, ALOMY, SETFA, DIGSA, ECHCG and SORBI with no visual injury recorded, during the 21 day test period.

Broad leaf weed species: EF-1315 applied post-emergence, at rates ranging from 337.5 to 2400 g ai/ha was completely selective to CHEAL, POLCO, CIRAR, VIOTR, ABUTH and AMARE, with no visual injury recorded, during the 21 day test period. Transient injury (≤ 10 %) was recorded on STEME, IPOHE and EPHHL following application of EF-1315. In all cases plants were recovering by the 21 day assessment. Symptoms of visual injury were necrotic spotting, tip bum and leaf cupping, which were all observed on the leaves present at the time of application. All subsequent new growth was healthy.

EF-1551
Crop species: EF-1551 applied post-emergence at rates ranging from 337.5 to 2400 g ai/ha was completely selective to ZEAMX, HELAN TRZAS and ORYSA, with no visual injury recorded, during the 21 day test period. Slight (5 %) injury was recorded on BRSNN and GLXMA following application of EF-1551. Symptoms of visual injury were necrotic spotting, tip burn and leaf cupping, which were all observed on the leaves present at the time of application. All subsequent new growth was healthy.

Grass weed species: EF-1551 applied post-emergence at rates ranging from 337.5 to 2400 g ai/ha was completely selective to AVEFA, ALOMY, SETFA, DIGSA, and SORBI with no visual injury recorded, during the 21 day test period. Slight transient (5 %) injury was recorded on ECHCG following application of the 1200 and 2400 g ai/ha rates of EF-1551. Fourteen days after application ECGCG plants had fully recovered. Symptoms of visual injury were necrotic spotting, tip bum and leaf cupping, which were all observed on the leaves present at the time of application. All subsequent new growth was healthy.

Broad leaf weed species: EF-1551 applied post - emergence at rates ranging from 337.5 to 2400 g ai/ha was completely selective to STEME and VIOTR, with no visual injury recorded, during the 21 day test period. Transient injury (≤17 %) was recorded on CHEAL, STEME, PLOCO, CIRAR, ABUTH, AMARE, IPOHE and EPHHL following application of EF-1551. In all cases plants had either recovered or were recovering by the 21 day assessment. Symptoms of visual injury were necrotic spotting, tip burn and leaf cupping, which were all observed on the leaves present at the time of application. All subsequent new growth was healthy.

GF-1688

Visual injury was only observed at the 2400 g ai/ha rate of GF-1688, on 8 of the twenty one test species evaluated and at the 1200 rate on 1 of the twenty four species tested. The symptoms of visual injury were necrotic spotting, tip bum and leaf cupping. These symptoms of visual injury were only observed on the leaves present at application with all subsequent new growth healthy.

 

EPHHL was the most sensitive species to post-emergence applications of GF-1688, with a maximum score of 20% for visual injury, recorded 7 daa, at the 2400 g ai/ha rate (highest rate tested). Injury to EPHHL was transient and only 5% injury was recorded 21 daa. The level of injury observed on EPHHL was significantly below the 50% required to trigger a Tier 11 test. (Guidance Document on Terrestrial Ecotoxicology under Council directive 9114141EEC).

EF-1315:

Visual injury was only observed with EF-1315, on three of the twenty one test species evaluated. The symptoms of visual injury were necrotic spotting, tip bum and leaf cupping. These symptoms of visual were only observed on the leaf present at application with all subsequent new growth healthy. EPHHL was the most sensitive species to post-emergence applications EF-1315, with a maximum score of 10% for visual injury, recorded 7 daa, at the 2400 g ai/ha rate (highest rate tested). Injury to EPHHL was transient and only 5% injury was recorded 21 daa. The level of injury observed on EPHHL was significantly below the 50% required to trigger a Tier II test. (Guidance Document on Terrestrial Ecotoxicology under Council directive 9114141EEC).

EF-1551:

Visual injury was observed with EF-1551, on ten of the twenty one test species evaluated. The symptoms of visual injury were necrotic spotting, tip burn and leaf cupping. These symptoms of visual were only observed on the leaf present at application with all subsequent new growth healthy. CIRAR was the most sensitive species to post-emergence applications EF-1551, with a maximum score of 17 % for visual injury, recorded 7 daa, at the 2400 g ai/ha rate (highest rate tested). Injury to CIRAR was transient and only 10% injury was recorded 21 daa. The level of Injury observed on CIRAR was significantly below the 50%required to trig0ger a Tier 11 test. (Guidance Document on Terrestrial Ecotoxicology under Council directive 91/414/EEC)

Validity criteria fulfilled:

yes

Conclusions:

None of formulations tested are likely to damage the long term growth and development of the test species.

Executive summary:

The objective of this study was to evaluate the post-emergence phytotoxicity of three Dursban

(chlorpyrifos-ethyl) formulations to a range of weed and crop species. Applications were made post-emergence using a track sprayer fitted with a Tee Jet 8002E flat fan nozzle, calibrated to deliver 185 l/ha.

A total of 8 crop species and 16 weed species from 15 plant families were tested in this study. The species evaluated represented members of the Gramineae, Leguminosae, Brassicaceae, Amaranthaceae, Chenopdiaceae, Euphorbiaceae, Convolvulaceae, Asteraceae and Malvaceae families.

 

None of the three Dursban formulations (GF-1668, EF-1315&EF-1551) tested resulted in 50%injury to any of the following species:A.myosuroides, A. fatua, E. Crus-galli,S.faberii, D.sanguinalis,S.bieolor,O.sativa, T. aestivum,Z.mays,C.esculentus,G.max, B. vulgaris. B.napus, G. hirsutum. C. album, I. hederacea, E. heterophylla, A. retroflexus, A. theophastic, H.annus,S.media, C.arvensis, P. convolvulusandV. tricolor. In all cases injury was transient and was only observed on the leaves present at the time of application. With all subsequent (post application) new growth healthy. Therefore, it is concluded that none of formulations tested are likely to damage the long term growth and development of the test species.

Description of key information

Pre-emergence and post-emergence photoxicity was not observed at levels requiring further testing. no guideline followed. K2