One of the most important parts of growing and storing potatoes is the cleanliness of a store when the potatoes come in. This year will have an extra challenge for any growers who have used Clorpropham, CIPC, as the task of removing as much residual CIPC from the store to comply with any tempMRL or MRL that will be set soon.
Store maintenance and deep cleaning should be a priority job carried out every season by growers. Care is taken in seed selection, planting, growing and eventually harvest to produce a marketable crop that you would like to stay marketable for as long as possible.
Having a crop of potatoes that are good for sale to the intended market after three to eleven months after harvest is achievable. If you are going to the trouble of maintaining and cleaning stores then make a note of it, use a simple spread sheet to make a list of what was fixed, serviced, cleaned, who did the work and when. This is useful for all types of on farm audits and if you have used CIPC then it can also be used to show your efforts to remove any remaining residue.
As soon as your store is empty, open all doors and vents and leave them open. Concrete floors and other surfaces will become wet after the doors are opened, cleaning should not start until all the condensation has dried up. turn the fans on for about five minutes to remove any loose dust and swap the air for fresh air and the cleaning process can begin. Have a pencil and notebook handy to to note any repairs needed to the structure of the building as you go. equipment required are a forklift and cage or cheery picker to reach high areas safely. Never get raised up in anything attached to a forklift like a pallet or a potato box. You will also need scrapers, hand held brushes, an industrial vacuum cleaner with an extra long hose, rubble sacks for collecting any contaminated material if CIPC was previously used, a pressure washer and also PPE to keep you and any one around you safe during cleaning, This includes dust masks, goggles, bump caps, gloves, protective foot wear, a high viz item, torch, charged phone or a two way radio.
Start as high as you can and can and scrape off and brush any where that dust can gather and build up. After you have worked your way down to ground level, sweep the floor to remove any large pieces of earth, old potatoes, bits of wood, etc. and remove. Remember any access routes, wooden chambers or floor ducts. If the store was previously treated with CIPC, any sweepings and debris should be placed in rubble sacks, the bag should be labelled that the contents contain Chlorpropham. The bag should then be disposed of via a your local waste transfer company.
Fridge units need cleaned to, they suck dust through them all the time they are running and a lot can gather in there. This can be carried out by the company who services your equipment or by your team on farm. Remember to isolate the power before doing any cleaning. Remove the side panels and you have access to the inside, the drip trays and the evaporator coils which all get a bit dirty during the season. The store should now be free from larger particles of dust and debris so is ready for a final vacuum to complete this stage of the cleaning process.
The store is now ready to be washed with a pressure washer to do a final clean and remove the thin layer of dirt still stuck to the floor and walls. Please ensure the power is isolated to fridge units, fans, power sockets in the store etc. before washing commences.
Although your store is now clean, it is not sterile. Many pathogens are still present and as soon as the process of store loading begins , spores, sclerotia, etc. are thrown into the air from forklift trucks moving and fans moving air around and land on the fresh new tubers you have cared for in the field. The best way to sterilize a store is through fogging with a product like peroxyacetic acid, Jet5. This will kill a high percentage of the spores. This is also a good time to sterilize potato boxes. Boxes should be cleaned, washed if really dirty and stacked in the store with a small gap between rows to allow all round sterilization. Any boxes not going in the store should be cleaned and stacked
to allow UV light to reach the box in blocks of four stacks with a gap all around before the next block of four.
This store is now ready to be filled with high quality seed or ware potatoes for long or short term storage.