P1901289: AHDB Research Call - Potatoes: Residual and Contact Herbicide trials 2019

P1901289: AHDB Research Call - Potatoes: Residual and Contact Herbicide trials 2019

Background information for Strategic Farm programme

The Strategic Potato (SPot) farm programme includes four farms in England (North, East, West and South West). The farms demonstrate new ways of working in a commercial setting and, as approaches are subject to full cost-benefit analysis, farmers and growers can assess the possibility of changing approaches on their own farms. Key elements include trials and demonstrations of relevant research in the sector, along with knowledge exchange activities to share the results to the wider industry.


To co-ordinate, and delivery of, field trials and demonstrations for herbicides in potato crops.


This research will inform guidance to potato growers on the range of products available for use as herbicides in potato crops and their ability to inhibit a range of weed species. This research is closely aligned with the AHDB Potatoes knowledge exchange programme and therefore the sites are located on the Strategic Potato (SPot) farms.

Tenders are requested from one lead contractor to be responsible for both scientific co-ordination and trial implementation, but the work at individual sites may be sub-contracted out if desired. 

  • SPot North DN20 0NU (Full replicated trial)

  • SPot East TBC (Demonstration)

  • SPot South West TA19 9EG (Demonstration)

  • SPot West SY4 4HG (Full replicated trial) 

Two the above sites (SPot East and SPot South West) will be demonstration only (no replication). These sites will look at contact herbicide replacements for diquat, including timing of application of contact herbicides. The other two sites (SPot North and SPot West) will be fully replicated trials studying the residual herbicide aclonifen in mixes with other residuals.

Replicated trial design – SPot West and SPot North

The aim of the replicated trials is to study the efficacy of aclonifen in combination with a range of other available residual herbicides. A secondary aim is to observe potential phytotoxicity effects of the residuals used.

The trial will include two varieties (see below) and eight treatments (see below). Plots should be four rows (two beds) and eight metres in length, with four replicates.


Two varieties will be used for each replicated trial. Maris Piper will be included across both fully replicated trial sites (SPot W and SPot N), and a second variety will be included at each site as agreed with hosts.


Tenders should list proposed treatments (eight treatments to include appropriate controls), but these may be modified after industry consultation. Treatments should include mixtures of residuals, +/- contact, and with / without aclonifen, and state rates.


Varieties should be machine planted for the replicated trials, as close as possible to timings of the commercial crop. Timing for herbicide application to be agreed with the scientific co-ordinator.


  • Weed counts by species, approximately one month after planting

  • Phytotoxicity assessment

Demonstration design

The aim of the demonstrations is to observe the effects and safety of timing of application of alternative contact herbicides (as replacement for diquat) for early post-emergence use. A secondary aim is to observe potential phytotoxicity effects of the residuals used alongside.

Treatments and Timings 

  1. Diquat + residuals

  2. Carfentrazone-ethyl + residuals

  3. Untreated control (hand weeded soon after emergence)

  4. Untreated control (fully untreated)

Tenders should propose one combination of up to three residuals to use in conjunction with the contact herbicides. These may be modified after industry consultation. Residual herbicides which may cause phytotoxic effects are preferred. 

Products to be applied at three growth stages:

  1. One week prior to ground heave (~one week pre-crop emergence)

  2. At 10% emergence

  3. At 75% emergence

The contractor must be able to visit site regularly to monitor emergence and apply products at the correct growth stages.


Three varieties will be demonstrated, decided in conjunction with the host. Varieties should be hand or machine planted for the demonstrations.


  • Ground cover assessment post-treatment weekly up to 100% ground cover or up to six weeks post emergence, whichever is sooner.

  • Weed counts by species approximately one month after first application

  • Simple phytotoxicity visual assessment

Scientific coordination (for both demonstration and replicated trials)

  • Write a protocol based on the information in this call and send to implementing contractors.

  • Discuss the protocol with sub-contractors if applicable to ensure they understand and can adhere to it.

  • Visit the two fully replicated sites before treatments are imposed.

  • Plan trial layout (in conjunction with implementing sub-contractors if applicable).

  • Provide method and scales for assessment of efficacy (i.e weed counts / phytotoxicity assessment. These should be in-line with the EPPO guidelines attached for the replicated trials.

  • Ensure that treatments are applied at the correct stage and dates, and that measurements are made and reported correctly, if applicable by maintaining contact with the implementing sub-contractors.

  • Collate results, conduct statistical analysis and write a report to include economic assessment of the products.

The scientific coordinator may be asked to provide a maximum of three presentations as part of AHDB’s Knowledge Exchange programme. These will be paid separately at the standard AHDB rate, currently £475 per day plus T&S.

Trial implementation (for both demonstration and replicated trials) 

  • Exclude from tenders for implementation payment to host for losses from the trial area. Provision for this will be made by AHDB.

  • Fields have been selected or will be identified in the winter by AHDB in conjunction with host farms.

  • Liaise with the host farmers to decide a suitable position in the commercial field(s) for the trial.

  • The host farm will prepare the site including fertiliser and nematicide if required, and will control late blight as for the commercial crop on the same field.

  • Plant, by machine, or by hand for demonstrations only, within a few days of commercial planting in the host field.

  • Impose treatments using a suitable sprayer to apply accurate quantities to each two bed plot without overlap. 

  • Conduct the agreed assessments as applicable and provide records of assessments promptly (to the scientific coordinator if applicable).

Please also provide: 

  • Statement of availability of and description of machinery appropriate to the treatment application and establishment of the trial. 

  • Applicant details, including the project leader and sub-contractors, if applicable. 

  • Details of previous experience and work in this field, to include scientific and technical expertise of staff involved in this project.

Product cost should not be included in the contractor’s proposal. This will be reimbursed at cost. Product to be sourced by the contractor.

Once the successful contractor has been notified, an inception meeting will be arranged in March to finalise the experimental design, timeline and protocol.


 Minor changes to the protocol may be made after the award of the contract by agreement between AHDB and contractors.

Application Procedure

Applicants should complete an AHDB Research and KE Application Form – Full Proposal Small, referring to the guidance notes to aid completion. 

Applications are made on the basis of the AHDB Research Funding Agreement and any organisation receiving funding shall comply with the terms and conditions specified in the RFA. AHDB will not be held responsible for any expenses or losses incurred by applicants in the preparation of an application(s).

Completed application forms should be submitted to research@ahdb.org.uk no later than 12:00 (noon) on the 28 February 2019.

Proposed timings for application and project delivery

Stage of Process


Call published

31 January 2019

Full proposal submission deadline

28 February (noon)

Applicants informed of outcome

12 March 2019

Project commencement

1 April 2019

Project completion

31 March 2020


If you have a specific question related to this call please email research@ahdb.org.uk. As part of the open tender process AHDB cannot discuss specific project details prior to submission of a proposal. All Questions and Answers are published.

Assessment criteria

The standard assessment criteria will be used.