Implementing novel, cost effective alternatives to CIPC for sustainable potato storage

Potato is a major UK and worldwide crop required year-round by consumers and processors. Due to seasonal production,
long term storage is necessary, during which tubers must be maintained with good quality for fresh consumption and
processing. Potato tubers are natural over-wintering structures with a tendency to resume growth during storage, resulting
in sprouted produce that is unsuited to processing due to compositional changes such as increased sugar levels. Multiple
strategies are used to extend dormancy and minimise sprouting and waste, including the application of sprout
suppressants such as chlorpropham. Development of viable alternative strategies to maintain tubers and bulbs in a
dormant state and long-term suppression of sprouting are top industry priorities. Long-term storage of potato tubers is
essential for year round supply. Maintaining sprout suppression and low reducing sugars during storage is essential
paramount for supply quality and minimising the formation of acrylamide; key priorities for the processing industry. Potato
storage is still heavily reliant on the chemical chlorpropham (CIPC) to manage sprouting but further restrictions are coming
into force and its future registration is under scrutiny. Registered alternatives are becoming available, but there are
industry concerns over efficacy, cost and potential taint issues (a key issue problem for end product flavour and consumer
acceptability). The proposed work will build upon recent research into developing novel, cost effective, benign,
physiologically-targeted storage interventions which will suppress sprouting and maintain low sugar. This offers a route to
incremental reduction in and ultimately the elimination of CIPC within the UK and beyond.

Long-term storage of potato tubers is essential for year round supply. Maintaining sprout suppression and low reducing sugars during storage of processing potatoes is paramount for supply quality and minimising the formation of acrylamide; key priorities for the processing industry. Potato storage is still heavily reliant on the chemical chlorpropham (CIPC) to manage sprouting but further restrictions are coming into force. The proposed work will build upon recent research and develop novel, cost effective, benign, physiologically-targeted storage interventions which will suppress sprouting and maintain low sugars. This offers a route to incremental reduction in and ultimately the removal of the use of CIPC within the UK and beyond.

The UK processing potato industry is worth £3.9 billion at retail and supports more than 20,000 jobs in the industry directly,
on farms, transport and in manufacture. To achieve year round potato supply in the UK approximately 1.5 million tonnes of
potato tubers are typically stored for up to 8 months each season. Maintaining ecodormancy (sprout suppression)
combined with low reducing sugars is essential for end product quality and mitigating risk of formation of the process
contaminant acrylamide. Current storage practices for processing potatoes are reliant on CIPC to suppress sprouting in
combination with higher temperatures to avoid cold induced sweetening. The potato industry and especially the processing
sector is dependent on CIPC for storage quality; in 2012, a total of 31T of CIPC was applied across 89% of the stored crop (Defra).
The continued registration of CIPC remains very uncertain given UK regulatory concerns over the increasing
number of recent MRL exceedances, non-target binding, and potential cross contamination with other crops, and the
likelihood for the persistence of CIPC and its breakdown products in the environment. There has been increasing and
concerted pressure from the Chemical Residue Directorate for the processing industry to reduce its use. Alternative
chemical solutions are becoming available, but there are industry concerns over efficacy, increased cost and taint; the latter
being a key concern for end product flavour and consumer acceptance. Although the CIPC Stewardship Group has
improved CIPC compliance, it is no exaggeration that without CIPC the UK processing potato industry at present would not
be economically viable. Critically, without viable alternatives to CIPC, storage duration could be reduced from 8 months to 4
months or less. Consequently there would be a reduction in demand for UK grown potatoes equivalent to 4 months supply
(~ 750 kT) with a nominal farm gate value of >£150M @ £200/t; with commensurate reliance on imports and impacts of
self-sufficiency. This project addresses this challenge directly by developing benign, cost effective alternatives to CIPC
which are based on novel physiological insights and offers a route to incremental reduction in CIPC thereby ensuring
continued long-term storage capability and protecting domestic potato production and associated supply chains. Firstly, this
will counter the risk from future withdrawal of CIPC and the consequential contraction in the storage window from 8 to 4
months with associated reduction in demand for UK grown potatoes. Secondly it will address the limitations in existing and
emergent alternatives which either add cost, are less efficacious, risk elevated reducing sugar accumulation or leave a
taint. Adoption of these new technologies will not only secure UK potato production equivalent to 4 months supply but also
will safeguard associated UK jobs. It will mitigate against imports (to offset supply shortfall) plus the associated increased
transport costs and additional GHG emissions plus reduce the risk to quality from extended transport distances. The
adopted technologies will directly reduce and ultimately eliminate the use of CIPC, mitigating against MRL exceedances
and lowering residual CIPC in the environment. These technologies will require new approaches to potato
storage.Through its close supplier relationships PepsiCo is well positioned to drive adoption of the successful solution(s) in
a framework which allows the technologies to evolve alongside reduced CIPC use whilst mitigating risk and ultimately
building confidence and a commercial pull for the technologies.