United Kingdom Potato Harvest 2017 without drama - but now the storage...

Feedback on this season’s harvest suggests that there are not too many dramas out there, although storage appears to be in short supply, probably because of a combination of high yields as many crops bulked quite late (hollow heart is a reported problem) and current market conditions reducing options to move crop off the field. If temporary or ‘overflow’ storage is being used, please note the information below about CIPC use.

There have been some isolated but, as yet, unquantified reports of rots including pink rot (Phytophthora erythroseptica) and [late] blight (Phytophthora infestans). These appear to be limited to areas where there was a lot of rainfall which may have impeded spray programmes and/or left waterlogged patches in the field to enable the fungi to spread. Slugs are also an issue in some areas.

It appears that these problems are not only affecting the UK. Interestingly, this photo of an extensive blight infection was tweeted by a Belgian research colleague in mid-October who described it as a ‘sting in the tail’, as tuber blight can often go unnoticed until the symptoms have developed in the store. Have you checked your crops? Suffice to say, there is no point in incurring further cost storing a crop like this with no prospect of sale.

New product labels tighten laws further on CIPC application

The latest changes to CIPC product labels, introducing new requirements for the use of lower application rates for this storage season, have been confirmed and have recently been communicated out to users by the Potato Industry CIPC Stewardship Group.

The NAAC CIPC Applicators’ Group has confirmed that applications will not be made if fog is not able to be recirculated. This is for residue control purposes as well as efficacy at the lower dose rates. In stores with positive ventilation (bulk stores and some box stores), active recirculation is most easily achieved by fitting an inverter (also known as a variable frequency drive or VFD) to use the store’s ventilation system at slow speed. In overhead throw box stores, active recirculation can be brought about using an air separator or duct at the end of the store to create an ‘open suction’ system. Alternatively, fan-assisted plenums placed within box stacks will ensure active recirculation can be achieved.

Different approaches are detailed in the PICSG’s CIPC Application: A Store Owner’s Guide, which is available at http://www.cipccompliant.co.uk/uploads/fileman/cipcapplicationguide.pdf It is recommended that users consult their NAAC CIPC Applicator to discuss this requirement now to ensure that, if steps have not yet been taken to modify stores, applications can still be made this season. For further information, see the PICSG ‘Be CIPC Compliant’ website – http://www.becipccompliant.co.uk or, for best practice advice, call the AHDB’s Storage Advice Line on 0800 02 82 111.

Finally, it is important to note any food, feed or seed, other than ware potatoes, should not be held in stores, which have been treated with CIPC. This is because CIPC penetrates the store fabric and is then re-released risking damaging seed and potentially contaminating food and feed. The Maximum Residue Level for CIPC in anything other than potatoes is the limit of detection (0.01 mg/kg). There is more information on this on the Red Tractor Farm Assurance website.