Potato Review

www.potatoreview.com POTATO REVIEW JANUARY/FEBRUARY 2021 43 STORAGE is covered a number of crisping varieties and also two particular chipping varieties which were found to be particularly at risk, all destined for storage beyond the end of March 2021. “We also are grateful for the support of the FPSA and BPTA who worked as part of the team, supporting the processing sector, while recognising that their challenge was not as acute as for the processing sector and that there would be no emergency approval for the fresh-pack and fresh chipping sectors.” e nal application was submitted by the AHDB at the end of July, and was intended for the ECP meeting on September 22nd. In parallel, in early September, contact was made with Prof Gideon Henderson, the Chief Scienti c Advisor for Defra, by NFU President, Minette Batters. is underscored the need to support UK growers with emergency approvals where necessary, and included the case of 1,4-DMN. However, despite these actions and a letter co-signed by BPTA, FPSA and PPA, being sent to the Minister for Farming Fisheries and Food, Victoria Prentis, emphasising the urgency of the matter - and her assurance it would be attended to as soon as possible – the application was not considered at the September meeting. As the next meeting of the ECP was not until November 24th, work behind the scenes continued. “One of the challenges of getting the application before the ECP committee is that it does not publish an agenda online until the last moment, so applicants cannot see whether it will be discussed,” said Andrew. Adrian Cunnington, Head of Crop Storage at AHDB, is hopeful the emergency authorisation of 1,4 DMN for this season will lead to its full approval as an option for the whole industry in 2021/22. But this will still be dependent on the full application from DormFresh receiving clearance by next summer. “If DMN gets approved, this will boost our portfolio of options signi cantly, particularly for long-term storage. Alongside the current options, plus with the advent of some other new molecules expected onto the market very soon, including orange oil, growers will be in a much better place to manage their stores going forward,” he said. “But it is important to realise that all of this new chemistry needs to be used as part of a wider strategy of integrated store management. All the products work di erently to CIPC and need to be managed more precisely that was necessary before.” 1,4 DMN AN EFFECTIVE SPROUT SUPPRESSANT Sutton Bridge Crop Storage Research researcher Adrian Briddon, who has been directing trials investigating the e cacy of the product, talks about some of the technical details of 1,4-DMN- and how to get the most from it. He said: “1.4-DMN has been approved for a few years in a number of European countries – including the Netherlands – and has been shown to be very e ective as a sprout suppressant. “Our work at SBCSR has shown the product works at all stages of dormancy. While it is called a dormancy enhancer, and it is best applied before dormancy break, it is also a very effective sprout suppressant applied to non-dormant crops in store. This is where it will be valuable at the end of the season, now we have secured the emergency approval, especially for long-term crisping crops. For applications to be most e ective, he recommends stores should be full. is is because 1,4-DMN forms a vapour in the store atmosphere and so large, unnecessary air spaces dilute the treatment. “Stores should be sealed for application for 48 hours to improve the uptake of 1,4-DMN vapour from the store atmosphere, into the tubers,” he explains, adding that 1,4-DMN should be recirculated for a short period of around 15 minutes after application. e extended store closure period means that application will need to be with electric or heat exchange hot foggers, rather than the petrol ones which were often used for CIPC. “1,4-DMN is more dynamic than CIPC, and it needs greater attention to detail. Being volatile, the product will be lost from the store at a greater rate than non-volatile CIPC. “Storemanagers will need to inspect crops regularly to see when re-application is necessary. All other things being equal, this is likely to be before CIPCwould have been re-applied. “We understand that if it is approved, the full label rate is likely to be 120ml/t. Such volumes are not often used though; 60ml/ tonne is more usual.” Adrian Briddon AHDB Andrew Curtis Minette Batters Tim Rooke Victoria-Prentis