Sodium azide

Toxicity to soil macroorganisms except arthropods

Administrative data

Endpoint:

toxicity to soil macroorganisms except arthropods: long-term

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

2004

Materials and methods

Test guideline

Qualifier:

no guideline followed

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Sodium azide

EC Number:

247-852-1

EC Name:

Sodium azide

Cas Number:

26628-22-8

Molecular formula:

N3Na

IUPAC Name:

sodium azide

Sampling and analysis

Analytical monitoring:

not specified

Details on sampling:

- Concentrations: 0, 50, 75, 100, 125, 150, 175, 200 lbs a.i. / A.

Test substrate

Vehicle:

yes

Test organisms

Test organisms (species):

other: Meloidogyne incognita

Animal group:

nematods

Study design

Study type:

field study

Substrate type:

natural soil

Limit test:

no

Total exposure duration:

5 h

Post exposure observation period:

SEP 100 was applied in 3/4" water during a 5 hr period and this was followed 7 days later with an additional 1" of water to move the residual material deeper in the soil profile, and 1/2" one week later right before planting of cantaloupe on 4 June. Soil samples for nematode analyses were taken from every plot on 11 August.

Test conditions

Test temperature:

no data

pH:

6.2

Moisture:

no data

Details on test conditions:

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Pesticide use history at the collection site: no data
- Collection procedures: Soil samples consisted of 1-inch diam. soil cores taken from the root zone of each plant to a depth of approx. 10" have 8-10 cores/plot. The cores were composited and a 100 cm3 sub-sample was used to extract nematodes with the salad bowl incubation technique. Roots from 2 plants/plot were dug out [8 August] and after washing were rated for root-knot according to a 0-10 scale where 0 represents no galls and 10 maximal galling
- Soil texture (if natural soil): silt loam
- Organic carbon (%): <1.0%
- CEC: <10meq/100gms soil

Nominal and measured concentrations:

no data

Reference substance (positive control):

yes

Remarks:

methyl bromide 300 lbs/A; 2% chloropicrin

Results and discussion

Effect concentrations

Duration:

5 h

Dose descriptor:

LC100

Effect conc.:

>= 50 other: lbs/acre

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: incidence

Details on results:

All application of Sodium azide resulted in crop cover equal to that obtained with methyl bromide and practically eliminated root-knot and juvenile populations of M. incognita.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Executive summary:

The efficacy of Sodium azide for control of root-knot nematode [Meloidogyne incognita] in cantaloupe [Cucumis melovar.cantalupensis] was studied with field experiments in 2003. Sodium azide was delivered pre-plant into soil by drip irrigation using the SEP 100R [American Pacific Corporation, Las Vegas, NV, U.S.A.]. The compound was applied at rates within the range of 0 - 200 lbs a.i./A and methyl bromide [MB 67-33] was injected at 300 lbs/A to serve as positive control. The experiments were sited in fields naturally infested with the nematode. Application of Sodium azide, at rates >50 lbs a.i./A eliminated root-knot. Total and marketable yield increased significantly in response to rates of 50 and 75 lbs; however, there was no additional yield benefit obtained with the use of higher rates. Application of Sodium azide at rates ≥100 lbs, in either no change or in gradual decline in yields with severe phytotoxicity observed for the two highest rates [175 & 200 lbss]. Control of root-knot, seedling and root diseases, and weeds with sodium azide at rates of 50 and 75 lbs was equivalent to that obtained with methyl bromide. Results suggest that Sodium azide may be a good substitute for soil fumigation with methyl bromide in cantaloupe production.