Storage technology of sweet potato

I. problems that are easy to occur in sweet potato storage

Sweet potato is prone to chilling injury, germination and decay during storage. Sweet potato is warm and afraid of cold and humidity, the suitable temperature for storage is 10 ~ 14 ℃, and the relative humidity is about 80%. Chilling injury was easy to occur when the temperature was lower than 10 ℃, and sunken plaques appeared in the epidermis, which led to decay. Sweet potato has no physiological dormancy period, and will sprout at any time if the temperature is high (15-20 ℃), the relative humidity is more than 85% and the ventilation is not good. Germination consumes internal nutrients and makes it inedible. The skin of sweet potato is thin, it is easy to be damaged during harvest, the injured potato is easy to be infected by bacteria, and the sweet potato which is damaged and infected during storage is easy to deteriorate and rot in case of high temperature and humidity. It was easy to develop soft rot at 15-25 ℃ and black spot at 23-27 ℃.

II. Key points of storage technology of sweet potato

1. Disinfect the storeroom. The potato cellar used for storage should be cleaned and carefully disinfected, usually fumigated with sulfur, burned at more than 5 to 15 grams per square meter, sealed and fumigated for 24 hours, and then fully ventilated.

two。 Harvest at the right time. Sweet potatoes are vulnerable to cold injury and must be harvested at the right time. The timely harvest temperature should be 12-15 ℃, not lower than 10 ℃. After drying on the harvest day, it should be packed in baskets (boxes) and stored in baskets. do not stay out overnight to prevent cold injury or rain at night, resulting in sweet potato rot.

3. A selection of potato chips. The sweet potato used for long-term storage should be strictly selected, the potato blocks harmed by injuries, frosts, blisters, diseases and insect pests should be removed, and the good potato pieces with moderate size, no injury and no disease should be selected for storage. In order to prevent infection, the potato pieces can be soaked in 100-fold solution of 70% methyl topiramate for 3 minutes, removed and dried and stored.

4. Callus treatment. The specific method is: immediately after harvest, under the condition that the temperature is 3035 ℃ and the relative humidity is 90% 95%, the water loss rate is 2% 6% after treatment for 4 days, so that the damaged surface protection structure of sweet potato can be restored. The callus should be carried out in the storage room or cellar. Once the callus is completed, it should be changed to the normal storage temperature and humidity condition, and it should not be moved again in order to prevent new trauma.

5. Strengthen management. The management of sweet potato should be strengthened during storage. At the initial stage of storage, if the storage temperature is high and the humidity is high, it is easy to make potato pieces germinate or become infected. Therefore, should be turned on ventilation, cooling and dehumidification. In the middle of storage, the external temperature is very low, and sweet potatoes are vulnerable to chilling injury. During this period, sweet potatoes should be properly kept warm (more than 12 ℃) to avoid the harm of low temperature. If cellar sweet potato is used, attention should be paid to: in the later stage of storage, the external weather warms up, the temperature gradually rises, and the respiration of sweet potato is enhanced. At this time, ventilation should be strengthened in the cellar to prevent the accumulation of carbon dioxide released by respiration from causing "stuffy cellar" rotten potatoes.

6. Pay attention to the method. The cellar capacity of sweet potato should not exceed 2amp 3, leave space for ventilation and moisture drainage, and prevent "stuffy cellar". Storage temperature of 10: 14 ℃ is appropriate, strengthen ventilation and dehumidification, relative humidity is controlled at about 80%, anti-freezing, anti-stuffy, anti-rot. If diseased potatoes are found in storage, they should be picked out immediately to prevent spread.