Germination inhibition in potatoes, how did it go again?
This year again, there are major differences in harvest conditions. A number of batches have only just been stored and these batches of potatoes arrived with wet soil and rotten potatoes. Without heaters, it is difficult to dry them. Other batches are already nice and dry and germination inhibition has already started. The first batches are due for treatment again and that is why this article contains a few tips from a storage technology perspective.
Drying the product before starting the treatment
Ensure that the product is dry and free of condensation. This also applies to the fans, semi-circular steel ducts and the cooling system. With the germination inhibitors 1.4SIGHT, Biox-m and Argos, the combination of moisture and germination inhibitor can cause undesirable reactions on a number of materials. This means that internal ventilation must be provided beforehand to distribute any free moisture throughout the batch. Do this at 100% speed so that the same air comes into contact with the potatoes everywhere.
Drain the moisture from the cooling system
Also drain the moisture on the fins of the air cooler, in the drip tray and in the pipes of the condensation water drain. To do this, switch off the cooling and let the air cooler fans run 24 hours in advance so that the fins are dry. Then give the system time to drain the condensation water. Check whether the drip tray and drain are clean so that the water can be drained quickly.
Moisture also evaporates faster if a heater is switched on briefly to heat the room a little. Remember that gas and oil heaters also release water and CO2. Circulation fans and heat sticks can also be used to heat the room for this purpose. This also heats the materials in the storage, which reduces the risk of sprout inhibitors precipitating.
Do not use extreme refreshing
Extreme refreshing prior to application to bridge the long period without refreshing is not recommended. In combination with the administration of 1.4 SIGHT, it can cause extreme breathing. The CO2 level will therefore increase more quickly during and after the treatment.
Ensure good distribution
Administration via the outside wall is not possible with all new agents. Concentrations will then be too high there. The agent must be given time to be properly absorbed in the air flow. This is only possible if it is absorbed in the air flow above the product. Always read the label carefully to see which application method the storage location is most suitable for,
Ventilate during application
Leave mechanical cooling off before, during and after application. There are many known examples of damage to condensation water drains due to the crystallization of agents on cold and wet plastic materials. The air flow must always be started before the actual application.
Block the possibility of external ventilation and mechanical cooling. This air flow does not have to be at full capacity because the agent then has less time to adhere. So find a balance between good air distribution and a lower air speed. In practice, this means that the fans on a grid floor must run at least at 65%. With a ventilation wall (dry wall and airbags) and (above-ground) ventilation ducts, 80% is the minimum for good air distribution. If the air distribution is not good, there is a chance, especially between the ventilation ducts, that the sprout inhibitor will not end up in every place.
Ventilate after application
After application, the room for most sprout inhibitors must remain closed for 24-48 hours. Then ventilate internally again as normal. Then the air must be refreshed (shutters on automatic) to prevent CO2 from having a negative effect on the baking colour. Especially after treatment with sprout inhibitors, the potato can become more active, causing the CO2 content to rise more quickly. The cooling can also be switched on again after this period. If this is switched on earlier, condensation will again occur in combination with temperatures below 5 °C from the air coolers, this gives the chance of precipitation, especially 1.4SIGHT.
Other points of attention
- 1,4SIGHT can precipitate through openings in an adjacent cell. Make sure that all openings (cable ducts, doors, hatches, pipes) are sealed properly.
- When using Argos, make sure that the cables of temperature and RH sensors are free from the potatoes. Argos can precipitate on the cables, causing potatoes underneath to rot. Hang the cables so that they are free so that they do not come into contact with potatoes.
- Do not leave machines near potatoes in storage. Reactions of the agents with paint coatings are known.
- Spray the agents at a sufficiently high temperature. Argos in particular can cause violent combustion reactions to the product in droplet form.
Observe the safety instructions on the label. Also when, for example, fitters have to work on the storage installation shortly after administration. Make sure that there is sufficient external ventilation beforehand.