Celeriac, Apium graveolens var. rapaceum / Umbelliferae
Postharvest Atmosphere Management
Storage is usual in countries with severe winters, where the consumption has a great importance. This is the case of France, where the storage intends to supply the market from April until May, on the basis of the autumn harvest. The storage premises could be cellars where the temperatures do not reach freezing levels or provisional enclosures built on the field. The produce is placed in boxes containing sand or humid moss.
Modified atmospheres are scarcely used at commercial level for this species. Nevertheless, the conditions recommended are temperatures of 0ºC and gas concentration between 2-4% for oxygen and 2-3% for carbon dioxide.
Distribution
The average temperature recommended for distribution is between 10 and 20ºC. For distribution, the levels of moisture and ventilation must be the average.
Postharvest Problems
Among the alterations affecting celeriac we find loss of weight and parasitic diseases.
If celeriac is kept at 1ºC and 95% of relative humidity, the loss of weight will be around 1% per week. High potassium fertilization seems to reduce the loss of weight during storage.
Among the parasitic diseases, the most important is rot caused by Sclerotinia. The fungus that causes this rot, S. Sclerotiorum, has a fast growth, affecting the bulb and covering it with a white felt. This disease may attack during culture; therefore, some of the produce may have symptoms that favour the development of the disease during storage.