No. 10/24 SUBSCRIBER EDITION: please go to potatostorageinsight.com/subscribe to sign up as a Synopsis subscriber.
Dear Subscriber,
Hello! This is the October edition of Synopsis, your monthly potato storage update from Potato Storage Insight.
Potato harvest has been very much in focus this month for everyone as growers and store managers are challenged by a variety of weather conditions around the country. Generally, the overall picture has been one of continued but slow progress, albeit in far from ideal conditions for many, with sharp showers or longer spells of rain disrupting work for significant periods. Take a look at our best practice advice below for dealing with wet crops...
PSI activity
A new season has meant another round of work on a small amount of storage trials forming part of the GB Potatoes Strategy Potato Storage project which is continuing into 2024/25. Working with Simon Faulkner of SDF Agriculture and the University of Greenwich, we have successfully loaded a couple of respiration pods (right) into stores at the south Lincolnshire trials site. These will be monitoring tuber respiration in one fresh market and one processing store and data will be presented as part of the project output in spring 2025.
Adrian Cunnington will be involved in two UPL potato storage webinars being planned for October 22 and November 5; the events are part of a weekly series being run by the agchem company (see Forthcoming events).
Adrian will also feature in a storage efficiency workshop being held at the pre-Christmas CUPGRA conference (see Forthcoming events).
Best practice
Dealing with wet crops coming into store...
At the risk of repeating myself, I want to stress the importance of having positive ventilation available if you want to have any hope of keeping crops that have been harvested out of wet fields, like the one pictured above. The recent deluges have raised the prospect of very wet crops entering store and it is important not to turn a 'blind eye' to the weather if it has resulted in very wet or even waterlogged crops coming into stores.
Get the air onto the crop as fast as you can and keep the fans running until the crop is totally dried out. Run the fans at close to maximum speed for any drying operation; if inverters are fitted setting these at 95% (45 Hz) will mitigate the cost but should keep plenty of air moving. If possible, put boxes on a drying wall or, as an alternative, stack the boxes one or two high on a bulk store floor such as a grain store, if there is one available.
If conditions have turned cold (sub 7°C), look at adding a bit of heat to enhance the drying capability - i.e. the moisture-carrying capacity - of the air. You don't need much! Air at 12°C will work better, with less risk to the crop, than air at 20°C...
Waterlogging or rain on the trailer is bad news for stored potatoes. As previously discussed in these articles in Synopsis, water quickly blocks the breathing pores of the potato skin (known as lenticels) and - unless there is plenty of air available to dry it up - it's downhill from there, really. Not only do blocked lenticels prevent the tuber achieving good gaseous exchange to keep it alive, it also offers a great opportunity, as the lenticels ‘erupt’ and invert, for bacterial infection to set in.
This can result in rapid tuber breakdown in a matter of a few days - or less - and the crop cannot be stored. Keep waterlogged or 'rained on' potatoes separate at the front of the store or in an adjacent building, so they can be turned round quickly after harvest.
There's a lot more information on tuber lenticels in this review which is freely available on the 'net:
Bethke, P.C. (2023) Potato Tuber Lenticels: A Review of their Development, Structure, Function and Disease Susceptibility. American Journal of Potato Research, 100 253-264.