CIPC continues to hang in the balance

The potato industry group formed to promote the stewardship of the sprout suppressant chlorpropham (CIPC) has been held to account by the ACP (Advisory Committee on Pesticides).

Speaking at the Potato Council’s 2013 Winter Forum event, CIPC Stewardship Group Chairman Dr Mike Storey said that a report on the CIPC Action Plan was submitted to the ACP at the end of January. “This was a significant opportunity for the industry to demonstrate the progress made over the last five years,” he said, noting that there is still work to be done going forwards.

United front

The meeting with the regulators involved all the stewardship member organisations, including the companies that hold the approvals for the CIPC formulations*; the Potato Processors Association; the Fresh Potatoes Suppliers Association; the National Association of Agricultural Contractors (NAAC); Red Tractor, and the research institutes SuttonBridge and CranfieldUniversity.

Dr Storey explained that the results from the stewardship group’s Action Plan (figure 1) were showcased in the report, which clearly demonstrate the industry’s commitment to stewardship and the industry’s awareness of the serious implications of exceedances, that could see further restrictions on the use of CIPC.

Figure 1

CIPC Stewardship Group Action Plan (in summary)

• A committed cross-industry group responsible for the Action Plan

• A communication strategy to promote the uptake of best practice measures

• A commitment to support R&D relating to the variability of CIPC residues
• A Code of Best Practice for use of CIPC

• Industry monitoring for CIPC

• Annual fogger testing, BASIS training and operator certification



Yet despite the positive progress, MRL (Maximum Residue Level) exceedances above the 10mg/kg limit have been found again recently, which clearly shows the extent of the challenge and why the regulators continue to be concerned.  “If the industry fails to resolve the outstanding concerns, ACP will have no choice but to recommend regulatory action to Ministers, which could result in the withdrawal of CIPC,” stated Dr Storey.

Assessing areas for the industry to focus, he pointed to market research conducted in November 2012 that questioned 150 people responsible for the management of stored potato crops. “Encouragingly it showed that the majority reported that their practices have changed, indicating that best practice measures are being adopted.”


He outlined that there is increasing recognition of the importance of uniform air distribution through the store, with positive ventilation and the fitting of Variable Frequency Drives (VFDs) going a long way to limiting quantities of CIPC deemed necessary to protect tuber quality and avoid sprouting.

“This is great progress, but with other research also showing some quite consistent intervals between CIPC applications, the question is whether treatments are being made on a calendar basis, rather than being based on need, according to the sprouting level.

“This is a key issue,” said Dr Storey. “There is a real opportunity to look at total dose of CIPC being applied, and look at where it may be reduced. The industry data shows that the crop will ‘hold’ for longer if the first CIPC treatment is applied early – so intervals are extended when timing is optimised, thus making every treatment go further and improving efficiency all round.”

He added that while the majority of CIPC exceedances have been tracked back to box stores destined for the fresh market, making these stores a key priority, he was clear that this should not lead to any complacency in the chipping and processing sectors.

Dr Storey concluded with three key ‘take home messages’. “Ensure CIPC recommendations are made by a BASIS qualified advisor; review the store check-list especially where modifications may be needed to improve ventilation management, and thirdly work with NAAC listed CIPC applicators to comply with best practice.” Key requirements and best practice CIPC stewardship are listed in figures 2 and 3.


Total dose

Fresh market: 36 grams/tonne

Processing (incl. fish & chip shops): 63.75 grams/tonne


Equipment must be inspected and certificated annually by NSTS


Applicators must adhere to the CIPC code of best practice, be qualified to NPTC PA1, PA9 and should be members of the National Association of Agricultural Contractors (NAAC) scheme.


Recommendations for CIPC must be made by BASIS qualified advisors


Stores should be inspected and reported as fit for CIPC application under the Red Tractor Farm Assurance Scheme


Overall responsibility for CIPC use lies with the crop owner – not the store manager or the CIPC applicator


Figure 3 CIPC best practice

• At store loading, remove as much soil as possible and ensure crop is dry and cured. Avoid holding varieties with contrasting dormancies in the same store and do not overestimate the time taken for curing.

• The first application must be made prior to dormancy break, don’t delay initial application if crop is warm or harvest is suspended before the store is full.

• Minimise sprouting pressure and CIPC requirement: Pull down as quickly as possible and hold at the lowest temperature that crop condition and end-use permit.

• Recirculate store air continuously for 6-12 hours to ensure temperatures are as even as possible prior to application. In stores with refrigeration, do this by turning off the fridge but leave the fans on. Be sure not to introduce warm ambient air that may cause condensation on cold potatoes, concrete floors or metal ductwork etc.

• Where fans are used during applications, fridge coils should be by-passed.

• Avoid making applications under windy conditions.

• Applications to part-filled stores and part-treatment of full stores should be avoided as application efficiency in these cases is frequently poor.