One of the key factors that directly affect the safety of the potato crop is the condition of the stored potatoes. Ideally, the potatoes are harvested under the following conditions: formed skin, cool air at night (not necessary if there are refrigeration units in the store), adequate soil moisture to ensure harvesting without earthen lumps, and a pulp temperature of about 15,5 ° C. In some cases, soil conditions and pulp temperatures can be extreme and therefore some storage adjustments may be required in the early stages. Here are some guidelines for correcting extreme conditions.
Cleaning in cool weather (from 10 to 15 °C ) in dry soil conditions
1. The temperature of the tubers is already within the limits required for the treatment period. It is recommended to select the interval mode of operation of the fans so that the temperature of the embankment remains stable, and the supply of oxygen required during the treatment period will also be ensured.
2. If possible, use outside air, if the temperature is close to the temperature of the pulp of the tubers.
3. If the outside air temperature during the daytime is dramatically higher than the embankment temperature, reduce or stop air intake from the outside and use the inside air to maintain a stable embankment temperature.
4. Potatoes stored under these conditions will take 2 to 3 weeks for a treatment period at a temperature of 10 to 12 °C and at a relative humidity of 95%.
Cleaning in cool weather (10 to 15 ° C) in wet soil conditions
1. The wet surface of the tubers is a suitable environment for the development of diseases and prevents air exchange of the tubers through the stomata. If the temperature of the pulp is close to the therapeutic one, it is necessary to ensure the continuous operation of the fans without the use of humidifiers. This will dry out the surface of the tubers. ...
2. The temperature of the supply air supplied to the embankment should be slightly lower than the temperature of the pulp of the tubers (by 0,5 -1,0 ° C).
3. As soon as the tubers are dried, it is necessary to ensure the conditions of the treatment period: temperature 10-12 °C at 95% humidity for 2 to 3 weeks.
Cleaning in cold weather (temperature 4,5 to 10 ° C) and in dry soil conditions
1. Under these conditions, potato tubers are very susceptible to bruising on the pulp - this requires more gentle harvesting.
2. It is necessary to raise the temperature of tubers to 10-12 °C. This can be done by means of interval ventilation, which accumulates the heat generated during the respiration of the tubers..
3. Humidifiers must be operated simultaneously with air supply fans.
4. If the weather conditions do not change, it is necessary to continue interval ventilation with humidification until the storage is full. If the weather conditions have improved and the air temperature has risen - it is necessary to change the program settings accordingly - it is recommended to pay special attention to the potato batches that are placed last
Cleaning in cold weather and in wet soil conditions (temperature from 4,5 to 10 °C)
1. The process of drying potatoes must be started immediately upon the fact of laying the tubers in the storage; continue until the desired result is achieved; make sure that the humidity inside the pile (storage) does not increase (by means of forced humidifiers or air supply of high humidity).
2. If cold, humid weather conditions slow down the drying process (achieving the desired result), you can smoothly increase the temperature of the air supplied to the pile by using heaters.
3. When the drying process is complete, the interval ventilation will provide the required amount of oxygen and, at the same time, accumulate the heat generated during the respiration of the tubers to heat the embankment.
4. As soon as the temperature of the tubers reaches 10-12 °C, you can proceed to the treatment period, lasting 2-3 weeks at a relative humidity of 95%.
Kimberly Research and Extension Center, IDAHO