Agricultural Research Management Information System

Home
Research Summary
Search
About Us
- ARMIS
- Brochure
Contact Us
Report
User Request
Data Input
Help
- Operation Manual
  - PDF
  - Video
- Program Area & Commodity
We have reached 37600 number of research entries at this moment.

- Logout

Research Detail

Home
Research
Detail

Determination of Pre Harvest Interval for Dimethoate and Cypermethrin in Major Vegetables

M. A. Rahman
Entomology Division, BARI, Gazipur

M. W. Akon
Entomology Division, BARI, Gazipur

Afroza Begum
Entomology Division, BARI, Gazipur

Abstract/ Executive Summary:

A study was conducted to determine the per harvest interval (PHI) for dimethoate in coriander, cauliflower, brinjal, country bean, cabbage and red amarenth,- cypermethrin in tomato, cabbage, brinjal, country bean and cauliflower depending on Maximum Res/due Limit (MRL) Set by FAOIWHo. Two supervised field trials were conducted and sprayed with the field dose of dimethoate (2 milL of water) and cypermethrin (J milL of water). Samples were collected at 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 and 14 days after spray (DAS). The quantities were above MRL up to 8 DAS for dimethoate in coriander, cauliflower and red amaranth; 7 DAS for dimethoate in bean and cabbage; 6 DAS for dimethoate in brinjal; 4 DAS for cypermethrin in bean and cauliflower and 3 DAS for cypermethrin in tomato, cabbage and brinjal. No residue was detected from any of the tested samples collected at 14 DAS The determined PHI were 9 DAS for dimethoate in coriander, cauliflower and red amaranth; 8 DAS for dimethoate in bean and cabbage; 7 DAS for dimethoate in brinjal; 5 DAS for cypermethrin in bean and cauliflower and 4 DAS for cypermethrin in tomato, cabbage and brinjal.

Keywords: Determination.Dimethoa te,Cypermethrin, Vegetables

Location:

Start Date:

End Date:

Program Area: Pest Management

Commodity: Cauliflower, Brinjal, Bean, Red amaranth

Objectives:

To determine the per harvest interval (PHI) for dimethoate in coriander, cauliflower, brinjal, country bean, cabbage and red amarenth

Methodology:

The standard for dimethoate and cypermethrin were obtained from Sigma-Aldrich Laborchemikalien, Gmbh P 0 Box-I00262 D-30918, Seelze, Germany via Bangladesh Scientific Pvt. ltd. Dhaka, Bangladesh. Standards of both the insecticides contained 99.6% purity. Marketable size of tomato, cauliflower, brinjal, country bean, cabbage, coriander, and red amarenth were collected from supervised field trials at 0, 1,2, 3,4,5,6, 7, 8, 9, 10, 11, 12, 13 and 14 days after spray (DAS) which were sprayed with dimethoate @ 2 ml/L of water and cypermethrin @ I mllL of water. The formulated product of dimethoate was Sungor 40EC and cypermethrin was Relothrin IOEC. The purity of formulated insecticides were tested in the pesticide analytical laboratory and found to be 100% pure. Extraction and separation: Field collected samples (250g) were cut down into small pices by knifeon white board and mix well. A sub sample of20g was taken into a wide mouth jar then 100 ml of hexane was added to it. Sodium sulphate (Na2S04) was also added with sample until water was removed from the sample. The mixture was then macerated with high-speed homogenizer (Ultraturax, IKA TI8 basic, Germany) for 2 minutes. The homogenized material was then poured into 250 ml conical flask and placed into the shaker (Orbital Shaking Incubator, Rexmed, Sweden) for 12 hrs continuous shaking. After shaking, the slurry was filtered through a Buchner funnel with suction. The flask and filter cakes were rinsed with 25 ml of hexane each. The filtrate was then transferred into 250 ml round bottom flask and was dried to 5 ml by evaporation using a rotary vacuum evaporator (Laborota-400 I, Heidolph, Germany). The concentrated filtrate was then transferred into 500 ml separatory funnel making 10 ml in volume. Around 20 ml methanol was added with 10 ml filtrate and shaked vigorously for 5 minutes. After shaking, the separatory funnel was set on stand and kept undisturbed for 5 minutes. Then the clear part of the solution from the bottom of the separatory funnel was collected in a vial which was then centrifuged at 1200 rpm for 5 minutes (Laboratory Centrifuges, Sigma-3K30, Germany). After centrifuge, supernatant was collected for injection. Before injection, this volume was again cleaned up by High performance liquid chromatography (HPLC) filter (0.2 PTFE) which was ready for injection. Detection and Quantification of pesticide residue in samples: The concentrated extracts were subjected to analysis by GC-2010 (Shimadzu). For organophosphorus (Dimethoate) FTD (Flame Therm ionized Detector) and for pyrethroid (Cypermethrin) ECD (Electron Capture Detector) were used. The capillary column used in FTD was A TTM-l, length 30m, Inner Diameter (ID) 0.25mm and film thickness 0.251lm and in case of ECD it was Optima I and length, ID and film thickness was same.

Source of Information: Annual Research report, Entomology Division, BARI, Gazipur, 2013-2014

Article Link (Online Journal):

Funding Source:

Budget:

Total Budget (Tk.) :

Achievement/Findings:

The left over residue of dimethoate in coriander had been detected up to 13 DAS, of which up to 8 DAS the quantity of residue were above MRL. At the 0 DAS the residue was 15.321 ppm and they were 11.705 ppm, 9.683 ppm, 6.387 ppm, 3.926 ppm, 2.037 ppm, 1.294 ppm, 0.962 ppm and 0.527- ppm at I, 2, 3, 4, 5, 6, 7 and 8 DAS, respectively. All these quantities were above MRL. The quantity gradually decreased down to 0.329 ppm, 0.136 ppm, 0.089 ppm, 0.040 ppm, and 0.017 ppm at 9, 10, II, 12 and 13 DAS which were below MRL (Anon. 2014). No residue was detected at 14 DAS. So, the PHI of dimethoate for coriander can be selected at 9 DAS.

Knowledge Management: Report/Proceedings