Potato store cleaning and hygiene

Store preparation

An annual inspection of buildings and hardware is an important step in store preparation. It can be carried out at the same time as store cleaning a few weeks before loading. Look for signs of fabric damage and take action to seal any gaps and repair any defective equipment.

Minimising disease risk

Ventilation and convection currents, caused by respiration heat from the crop, will circulate dust containing disease spores throughout the store. Major dust movement and dispersal also occurs when store activity, e.g. forklift truck movement, stirs up dust on the floor. The resultant dust cloud will settle on top of the crop, where the risk of condensation needed for spore germination is greatest.

Sweeping with a brush moves the heavier dust particles along the floor, while creating a cloud of lighter particles, which includes the majority of spores. Vacuuming loosens and removes all fractions of dust and, if fitted with a fine filter, will remove most harmful spores from the store. Vacuuming is, therefore, much preferred to sweeping.

Vacuuming is best for removing dust

Hygiene and disinfection

Clearing dust and stray tubers from storage areas and ducts will normally remove the majority of disease inoculum present. This is usually adequate for most ware crops. However, if wet rots have been a problem in the previous season, then steam-cleaning of the boxes and affected areas of the store is recommended.

If total removal of viable spores is required, for high‑health crops, disinfectant can be used. This is particularly relevant in stores where bacterial soft rotting or damage-related fungal diseases such as dry rot have occurred. Most disinfectants will not work without prior cleaning and removal of dust and debris as they are deactivated by organic matter.

Make sure any disinfectant used on parts of the store that are in contact with crops are food-safe and acceptable to your intended market.

Soft rot in box store

Boxes

Leaving boxes outside will allow light to kill viable spores. Empty boxes should not be stacked more than four boxes high for safety and, if stacked in pairs, a small gap between rows will help natural (UV) light to reach every box. However, outside stacking can reduce box life by up to 40%. 

Ensure that an inspection of box condition is undertaken annually to identify those that are in need of repair or replacement.