PSI Bulletin: April 2026
- 1 day ago
- 8 min read
No. 04/26 'OPEN' EDITION (FREE ACCESS)
If you wish to receive these bulletins every month, please go to potatostorageinsight.com/subscribe to sign up as a Synopsis subscriber.
Dear Potato Producer,
Welcome to the April edition of our monthly Synopsis storage bulletin from Potato Storage Insight.
PSI ACTIVITY
Potato Storage Day: Wednesday 20th May
supported by
&
Here's an update on plans for our third strategic Potato Storage Day, kindly sponsored by Farm Electronics and UPL.
Trade stand partners who have signed up include the following major players in the potato storage sector:
Farm Electronics Cornerstone Systems Restrain Company Certis Belchim Juno Plant Protection Pellcroft Engineering SDF Agriculture Crop Systems GridDuck / Produce Quality Centre Martin Lishman Fenland Mobile Services Frontier Agriculture | UPL HK Timbers Albert Bartlett Bradley Refrigeration Potato Storage Insight Welvent Store Diary CIPC Residue Monitoring Group Burgess Farms RS Cockerill Nene Potatoes Omnivent |
Pre-registration is now open for this free-to-attend event.
If you would like to come along, simply register by sending your name and company details along with contact email, for each person attending, to admin@potatostorageinsight.com A free lunch is included.
Event plan – Leadenhall Farm, Holbeach St Marks. PE12 8HB courtesy of Dyson Farming
(w3w///salaried.forensic.took)
09.30 Registration and networking
Project partners stands to be viewed on arrival.
Event partners as listed above, with more information on each below
Light refreshments available.
10.15 Introduction by Adrian Cunnington
Presentations on variety trials and the cold storage for fresh / table potatoes strategy used at Dyson Farming. Topics to include:
Storage regimes – cold temperatures & sprout suppression options at Dyson
Maleic hydrazide deployment including potential for use of new UPL FazorFlo
Store design performance in terms of air flow – Omnivent lateral flow system
Achieving evenness of temperatures throughout the stores
Energy use & storage costs with PSI in association with GridDuck
Respiration / weight loss – concepts and data update from the University of Greenwich 'pods' deployed at Leadenhall in 2025/26
Dormancy/varietal performance in SDF trials held under appropriate fresh and processing storage regimes
Storage control/recording in collaboration with Store Diary
Speakers include Simon Faulkner, Adrian Cunnington, Debbie Rees, Luke Corbett, Gregor Hoefter, Richard Colgan, Stuart Jackson, Adam Fryer
Hog roast lunch from 12.15
Refreshments
View exhibitors' stands
Further networking opportunities
1.30 Event close
Exhibitors and partners:
Albert Bartlett - leading packers and processors
Bradley Refrigeration - potato storage cooling systems for refrigerated stores
Burgess Farms - major supplier to Waitrose
Certis Belchim - multinational agchem supplier including maleic hydrazide
CIPC Residue Monitoring Group - industry body seeking data on residues to keep stores compliant
Cornerstone Systems - storage systems supplier including energy-focused controllers
Crop Systems - suppliers of storage buildings, ventilation/cooling and store control systems
Farm Electronics - storage and ventilation systems from Tolsma, global storage systems manufacturer
Fenland Mobile Services - NSTS compliance and application equipment testing/servicing
Frontier Agriculture - regional agronomy and agrochemical support
Greenwich University - research team working on post-harvest technological developments including respiration monitoring systems
GridDuck - energy monitoring for all types of crop storage systems
HK Timbers - pallet box supplier
Juno Plant Protection - supplier of spearmint oil sprout suppressant
Martin Lishman - suppliers of agricultural storage systems and control equipment
McCain - multi-national potato processor
Omnivent - suppliers of potato storage systems and controls
Pellcroft - Lincolnshire-based storage and handling equipment supplier
Potato Storage Insight - specialists on potato storage management and enhancement. BASIS trainer.
Restrain - producer and supplier of ethylene systems and generation technology
RS Cockerill - major Yorkshire-based packing and processing supply business
SDF Agriculture - agronomy triallists and advisors to leading growers in packing and processing
UPL - multinational agchem supplier including maleic hydrazide (FazorFlo, Fazor) & orange oil (Argos)
Welvent - suppliers of storage buildings, ventilation and cooling systems
Dyson farming - Lincolnshire multi-site grower hosting the event and supplying leading markets
BEST PRACTICE
Continue to monitor for optimal fry colour and avoid an end of season quality drop
This month, don’t forget to keep a close eye on crops in any stores that are still loaded. Whilst the recent priority is likely to have been getting the next crop into the ground, remember that what’s still in store will also need your attention at a time of year when crop condition can change quickly... and with a lot of crops not having found their intended market, you don't need to give your customer any reason for rejecting yours.
Senescent sweetening
As potatoes get older, they reach a point in storage - which varies appreciably by variety - when they can develop an irreversible form of sugar accumulation which can seriously compromise processing quality. This is known as senescent sweetening. Simply put, senescence is the tuber growing old. Essentially, from a biological perspective, it has done its over-wintering job and it will be trying to convert starch to sugar to fuel new growth (even though you have hopefully stopped that growth using a chemical sprout suppressant).
It is an important change that can take place in long-term stored potatoes for processing and differs from the usual sweetening caused by low temperature. Where varieties are stored warm, senescence is reached earlier.
The factor we have to consider this year (again) is accumulated heat from what was a hot summer and a continuing warm pre-harvest period last autumn. Any crop held at 8C or higher can, by this time of year, be considered at risk. Watch for a dip in your regular tests for fry quality, especially in any varieties where you may be ‘pushing the envelope’ a bit, i.e. they would normally have been down the road by now. This might include varieties such as Arsenal, Innovator or Lady Rosetta. Regular testing is the key to detection – if you see a change taking place put some crop in somewhere warm and re-test in a day or two. If fry colour continues to darken, it is a good indicator of senescent sweetening. Speak to your market and be ready to unload the store quickly.
There is more on senescent sweetening research below:
AHDB legacy pages summary:
And from the University of Greenwich:
TECHNICAL INSIGHT
CIPC RESIDUAL CONTAMINATION
If we stop measuring, we risk losing storage
by Adrian Cunnington, Chair of the CIPC Residues Monitoring Group
For several seasons now, the potato industry has been working through the legacy of CIPC. Much of the attention has, quite rightly, been on residue levels in stores that were historically treated. That focus was essential in the early years after withdrawal, but the latest monitoring results suggest the conversation needs to evolve.
The second year's data, just recently reviewed by HSE, continues to tell a reassuring story. Residues are still detected in some stores, yet levels keep falling and remain comfortably within the temporary Maximum Residue Level (tMRL) of 0.35 mg/kg. This aligns with what many growers and store managers are observing in practice, where improved store management, more rigorous cleaning and a better understanding of contamination pathways are steadily reducing background levels.
The issue now is not what the data shows, but whether we are collecting enough of it to sustain the regulatory position that allows these stores to remain in use.
The tMRL is reviewed annually and depends entirely on the industry demonstrating, with credible evidence, that residues remain within acceptable limits. Without that evidence, regulators have no basis on which to maintain it. This matters because a significant proportion of UK potato storage has some historical association with CIPC. If the tMRL were to lapse through lack of supporting data, many stores could fall outside compliance regardless of how low their actual residue levels may be. In effect, storage capacity would be at risk for administrative reasons rather than technical ones.
That is why the priority for the 2025/26 season is to strengthen the evidence base, drawing on results from potatoes stored for at least 60 days in facilities with a history of CIPC use. For many businesses, this does not require any change in practice; multi‑residue testing is already part of routine assurance for a large share of the crop. The gap lies in the fact that these results are not always being shared as part of the wider dataset that underpins the tMRL.
Submitting data is a straightforward process. Results are accompanied by a small amount of contextual information about the store, and all data is anonymised before being passed to the regulator. The intention is to build a representative national picture, not to assess individual sites.
It is also worth recognising why residues continue to appear at all. Although CIPC has not been used since 2020, it persists within the fabric of stores where it was historically applied. This behaviour is well understood and explains why residues can still be detected even where current practice is exemplary. It also reinforces the importance of end of season cleaning. Levels are declining, but the process is gradual and depends on consistent attention to detail year after year.
The industry has made steady progress in reducing residues and improving its understanding of how they behave in storage environments. The next step is ensuring that this progress is properly reflected in the data submitted to HSE to support the tMRL. Without a sufficiently robust dataset, the regulatory framework that currently allows these stores to remain in use becomes harder to justify, and the risk of losing storage capacity increases for reasons that have little to do with actual residue levels.
Data can be submitted to the CIPC Residues Monitoring Group direct by emailing Adrian at adrian@potatostorageinsight.com
or by visiting the GB Potatoes website at https://www.gb-potatoes.co.uk
DAVID NELSON RETIRES FROM BRANSTON
A stalwart of the British potato industry and most recent recipient of the British Potato Industry Award, David Nelson, the agronomy director at Lincoln-based packer Branston, has recently retired from that role after 35 years at the company leading key improvements in yields and quality across their potato production portfolio.
David is not quite ready to put his feet up on a permanent basis just yet, so plans to devote some time to his own business, David Nelson Agroservices, where he can be contacted at dnagroservices@gmail.com
SNIPPETS
Congratulations to Prof Simon Pearson, Director of the Lincoln Institute for Agri-Food Technology (LIAT) at the University of Lincoln. Simon recently received his MBE, awarded in recognition of his leading LIAT's innovative work on Robotics and AI in the food industry, from His Majesty The King at Windsor Castle.
Potato News Today reports
Storage may be where efficiency matters most
Potatoes force the industry to think beyond harvest. Nearly 82% of Idaho potatoes are stored for some duration, and US federal project information notes that storage losses from shrink and disease typically run "about 6-7% in most years", with higher losses possible when crops are compromised. UK best practice guidance likewise stresses that cooling the crop is the largest consumer of energy during storage.
That makes storage technology central to the potato efficiency debate. Better monitoring, better airflow management, better humidity control, and better energy performance are not side benefits. They all directly affect saleable volume, product quality, and cost per stored tonne.
Full article here.
FORTHCOMING EVENTS
If you are hosting a potato or agricultural industry event, please send details to admin@potatostorageinsight.com. Key dates for your diary with relevance to the potato sector in the coming months in UK and Europe include:
May
Leadenhall Farm, Holbeach St Marks, Lincs. PE12 8HB
June
Tue 16- Fri 19 LAST CALL European Association for Potato Research: Joint Section Meeting - Agronomy and Post-Harvest
Warsaw, Poland www.eapr.net
July
Sun 26- Thu 30 Potato Association of America Annual Meeting
New Orleans, Louisiana www.potatoassociation.org
August
Thu 13 Potatoes in Practice, Dundee.
Wed 26-Thu 27 Caythorpe Seed Potato Breeders Open Days. Save the date!
September
Wed 9 - Thu 10 Potato Europe 2026 field demonstration held near Hannover, Germany
November
Wed 18- Thu 19 British Potato Confex, Lincolnshire Showground
Sun 29-Tue 1 Dec Interpom. Kortrijk Expo, Belgium.
Please note that you, or a colleague, can subscribe to Synopsis at any time by going to potatostorageinsight.com and clicking on SUBSCRIBE. We can also now take payments by credit card. Call Adrian on +44 (0)7970 072260 if you have any questions.
Subscriptions: please note that, under our new quarterly billing process, detailed above, we will issue invoices as individual subscribers reach the end of each quarter following the anniversary of their last payment. Future subs. will therefore be invoiced at either the end of January, April, July or October. A full year's subscription is great value at just £9.50/month (£114 + VAT per annum), so please renew promptly. Unpaid subscriptions will be closed within 8 weeks of invoice issue. Thank you.
Synopsis is written by Adrian Cunnington and published by Potato Storage Insight Ltd., 45 Main St., Gedney Dyke, Spalding, PE12 0AJ. UK.
© Potato Storage Insight Ltd. 2026
Want to read more?
Subscribe to potatostorageinsight.com to keep reading this exclusive post.