RFT - Agrochemical Residue Field Trials - 2012


  1. In consultation with ACAC, to prepare and maintain a list of agrochemicals necessary to sustain successful leaf production and for which GRLs have to be set or reviewed.
  2. To produce a formal protocol for trial and testing procedures.
  3. To promote participation in this programme globally.
  4. To collate results of trials done under the formal protocol and make them available to ACAC.
  5. To collect already available field residue trial data from various sources and make them available to ACAC.


As described in the CORESTA Guide No.1, Guidance Residue Levels (GRLs) have been developed by the CORESTA Agro-Chemical Advisory Committee (ACAC) to provide guidance to tobacco growers and those in the tobacco industry interested in the application of Crop Protection Agents (CPAs), in compliance with the implementation of Good Agricultural Practice (GAP) in tobacco production. GRLs have been used worldwide as a reference when selling and buying tobacco. New CPAs are continually developed, and GRLs will need to be established in the interest of promoting responsible tobacco production. Residue data from field residue trials complying with the label instructions are an essential part when establishing new GRLs. However, in some cases, additional trials would be helpful to supplement data from CPA manufacturers or institutes. In order to create new and reliable GRLs, CORESTA decided to conduct additional residue trials and launched the dedicated Agrochemical Residue Field Trials Task Force. CPA candidates are being tested in tobacco growing regions of the world, including those in Africa, Asia, Europe, North America and South America. Cooperating companies participate according to their interest and involvement in the target trial areas. An invitation was sent to potential participants in early 2012 with positive feedback from 15 companies, and the kick-off meeting was held in Vienna, Austria, June 30, 2012. Interest has now expanded to 25 companies, with Japan Tobacco Inc. (JT) offering to conduct all laboratory analysis work.

In January 2016, the Task Force was changed to a Sub-Group as its work and activities were viewed as being long-term.

Taking advantage of available CPA residue samples during the trials, a residue degradation study is being conducted for some CPAs. Results will be provided to the CORESTA Agrochemicals Analysis Sub-Group.


Coordinator:  Naoki Watanabe, Japan Tobacco Inc., Japan -
Secretary:  Matthew Vann, North Carolina State University, USA -
Others:  Trial Executors and Task Force members (accordingly to availability)


  • Vienna, Austria, June 30, 2012
  • Sapporo, Japan, September 22, 2012
  • Lexington, KY, USA, January 20, 2013
  • Brufa di Torgiano, Italy, October 12, 2013
  • Raleigh, NC, USA, January 11, 2014
  • Quebec, Canada, October 11, 2014
  • Izmir, Turkey, October 24, 2015
  • Berlin, Germany, October 8, 2016
  • Santa Cruz do Sul, Brazil, October 21, 2017
  • Kunming, China, October 21, 2018
  • Victoria Falls, Zimbabwe, October 12, 2019

Achievements in light of the five original objectives (as of February 2014)

1.  GRL Candidates

ACAC provided a priority list of 23 CPAs for which GRLs should be defined (some GRLs have now been set for some CPAs):

1 Azoxystrobin 9 Ethion 17 Spirotetramat
2 Difenoconazole 10 Triazophos 18 Bitertanol
3 Indoxacarb 11 Fenamidone 19 Iprobenfos
4 Propamocarb 12 Flubendiamide 20 Thiacloprid
5 Tebuconazole 13 Clothianidin 21 Chlorfenapyr
6 Chlorantraniliprole 14 Dicofol 22 Prothiofos
7 Triflumuron 15 Teflubenzuron 23 Quinalphos
8 Triadimefon /
16 Iprovalicarb    

Among the above 23 GRL candidates, 13 are currently in trials (57%).

The residue definition of each CPA has been confirmed and the JT lab has completed method validation.

In addition to the above CPAs, others, not yet defined as candidates for GRLs, will also be evaluated for residues by some executors.  Among these are Valiphenal, Benthiavalicarb, Fluopicolid, Sulfentrazone and Mandipropamid.

2.  Formal protocol

Essential points of study design

  • Duration: 3 years
  • Number of trials: 3 replicates per location
  • Planting conditions: Minimum 3 treated rows per treatment (leaf from central row sampled for analysis)
  • Application:
    • Only 1 agrochemical tested compound per treatment plot (row)
    • Adjust the conditions of application to obtain the expected highest residue per the product label, taking into account:
      • Rate; highest label rate
      • Number of applications; highest according to the label
      • Application intervals; shortest according to the label but target harvest based on the product's labeled PHI
      • Pre harvest interval (PHI); Label instruction
  • Sampling: 2 samples based upon stalk positions (one lower stalk sample and one upper stalk sample).

3.  Participants and tobacco type

  • 25 executors from 17 countries
    • North & Central America: USA, Mexico, Cuba and Guatemala
    • South America: Argentina and Brazil
    • Asia: India, Indonesia and Thailand
    • Africa: Malawi and Zimbabwe
    • Europe: Germany, Italy, Bulgaria, Greece, Macedonia and Turkey
  • Tobacco type: 4 types
    • FCV, BLY, ORT and Dark air-cured (DAC)

4.  Collation of results under formal protocol

  • The 2013, 2014 and 2015 trials have been completed.
  • Sample receipt and analysis by the JT lab is ongoing.

5.  Collection of already available residue trial data

  • Residue data from the field trials have been provided by CPA companies and organisations.
  • Data on CPAs outside of GRL candidates could be used for the verification of the current GRL values and/or for the selection of further new GRL candidates.


Poster Presentation at University of Kentucky Burley Tobacco Tour, 13 August 2019


Updated September 2019