05 April, 2018

Unearth the 7 secrets to a successful field trial

By Javier Bartolomé

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Residues of plant protection products (PPPs) are inevitably present in or on food, even when they are applied in line with good agricultural practice. The upper limit of residue permitted on food or feed is the ‘maximum residue level’ (MRL), which, in Europe, is legislated by the European Commission based on scientific advice from the European Food Safety Authority.

MRLs are measured via crop residue field trials, which replicate the real-life agricultural conditions under which a plant protection product would be used. It sounds a simple enough procedure, but what studies are commonly used and what are the secrets to success?

Field trials for crop residue analysis

Tractor spraying plant protection product onto fieldThe term field trials covers trials conducted on crops grown under cover or in open fields. There are essentially two main types of field trial:

  • Decline trials, in which samples of the crop – or ‘raw agricultural commodity’ – are collected after application of the PPP and at specific times before harvest to see how the level of residue decreases over time
  • Harvest trials, which assess the residue remaining in the crop after it is harvested

These trials are used to both support initial registration of the plant protection product substance and re-register the substance; For example, the range of crops it is to be used on is extended, such as when the registration of a pesticide licensed for use on apples is extended for use on other fruit crops like peaches. 

For more information about Envigo’s Residue Analytical Services Envigo Residue Analysis Services.

Seven top tips for ensuring field trial success

The success of field trials can be enhanced by following some simple rules:

  • Site the trials to maximize diversity: select different countries and locations for your field trials to reflect the variations that occur in climate and farming practice throughout Europe. As a general rule, a minimum of eight trials per major crop are required, and if the registration is pan-European, then these eight trials must be done in both northern and southern Europe
  • Mimic farming practices used in real life: use the kind of equipment which would simulate that used commercially for PPP applications and usual farming practices
  • Ensure the crop is healthy at baseline and without potential problems: consider the location of the trial and try to cite the trial areas away from field margins where there may be interference from a PPP applied to neighboring fields
  • Optimize sample handling: ensure that samples are collected and frozen as soon as possible after sampling and at least within six hours. Maintain frozen conditions until samples are returned to the laboratory for analysis and ensure timing of the analysis reflects the stability of the sample
  • Have a team with diverse expertise: having a team with expertise in agriculture and analytics ensures the studies are designed to account for growing seasons, geographical diversity and any conditions specific for optimal sampling and chemical analysis
  • Plan ahead: an average study takes approximately ten months from application of the product to reporting; add to this the need to have a crop ready for application and you can see the importance of forward planning
  • Be flexible: by having access to a wide geographic spread of field capacity which you can flex, you can easily run studies in northern and southern Europe as required and under very diverse conditions

For more information about Envigo’s Residue Analytical Services Envigo Residue Analysis Services.

Looking to uncover the latest market developments in the Crop Protection Industry? Read more by downloading our insightful white paper. 

Future Focus: Crop Protection Industry informative white paper


About the author

Javier Bartolomé, has a degree in Agronomy and joined Envigo as a Field Principal Investigator in 1999. He is now manager of the field facility in Valencia which has held GLP compliance for over ten years, and is also Team Leader to the rest of the Study Directors. Javier has been involved in the design of the study plans and field activities for all study types in the Envigo portfolio

Areas of expertise include the routine analysis of crops, processed commodities and soil, as well as providing analytical support for environmental fateecotoxicology, livestock feeding and operator exposure studies

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Category // Crop protection, field trials