Pre-storage treatment and several storage methods of potato

1. pre-storage treatment

Pretreatment of potato before storage can inhibit potato germination and has a good effect on storage.

(1) After the potato is harvested, it can be dried in the field to distribute some water for storage and transportation. Generally, drying for 4h can obviously reduce the storage morbidity. Drying time is too long, potato will lose water wilting, not conducive to storage.

(2) Pre-storage of potatoes harvested in summer is in high temperature season. After harvest, potato chips should be stacked indoors, cellars or under shade for pre-storage. In order to facilitate ventilation, heat dissipation and overturning inspection, the pre-storage pile should not be higher than 5cm and less than 2m wide, and ventilation pipes should be placed in the pile for ventilation and cooling. To avoid sunlight, cover the pile with mulch.

(3) After selection and pre-storage, selection shall be carried out to eliminate diseases and insect pests, mechanical damage and wilting potato pieces, and attention shall be paid to handling them gently.

(4) Drug treatment with chemical agents for appropriate treatment, can inhibit the germination of potato, but also a certain sterilization and antiseptic effect. Spraying 0.2% MH on potato leaves 2 ~4 weeks before harvest inhibited germination of potato during storage, but the effect decreased obviously in rain within 48h (spring) or 72h (autumn) after spraying.

Potato harvested in summer and autumn in the south can be treated with methyl α-naphthylacetate or ethyl ester to prevent germination. The method is to dissolve 150g~250g of 98% of the above chemicals in 300mL of alcohol or acetone, mix them in 10kg~12kg of powdery fine soil, and evenly sprinkle them on 5000kg of potato piles. The potato stored in winter should be treated in the middle dormancy period, and the effect would not be good if the application was too late.

2. storage method

(1) indoor storage in some areas directly pile potato pieces indoors, bamboo buildings or other floors, but also useful brown bags will be put into potato pieces, pile or hang on the floor. This method is simple and feasible, but it is difficult to control germination. For example, drug treatment or radiation treatment can improve the storage effect. It is also possible to inhibit germination by covering and shading, which is ideal for storing potatoes harvested in rainy seasons. For cold climates such as Northeast China, storage of potatoes by stacking method was also successful. If large-scale storage, choose a well-ventilated, dry warehouse, fumigate with formalin and potassium permanganate mixture, and then select and pre-treated potatoes into the warehouse stacked, surrounded by boards and so on. In order to improve the utilization rate of space, it can also be stored indoors, code box, etc.

(2) Cellar storage in the dark, cool, ventilated, dry indoor or outdoor shade shed, with brick rectangular cellar, pool wall holes into flower wall type, for ventilation and heat dissipation, covered with fine sand 10cm~15cm, slightly compacted, this method is suitable for warm areas in the south.

The soil in northwest China is sticky and solid, and it is stored in wells or kilns. The storage capacity of these two cellars can reach 3000kg~3500kg. Because only ventilation at the cellar mouth is used to adjust temperature and humidity, the heat preservation effect is better, but it is difficult to cool down at the initial stage of entering the cellar, so precooling should be carried out.

In northern Liaoning, Jilin, Heilongjiang and other places, shed cellars are used for storage. The height of potato pile in cellar should not exceed 1.5m, otherwise the temperature in pile will increase at the beginning of cellar, and it will be easy to sprout and rot.

Cellar potato is easy to sweat on the surface of potato pile. Therefore, grass curtain can be placed on the surface of potato pile in cold season to transfer sweat layer and prevent germination and decay. Cellar potato generally does not move after entering the cellar, but in the south of Northeast China due to higher cellar temperature and longer storage period, it can be reversed once or twice as appropriate to remove rotten potato pieces to prevent spread.

(3) The trench buried in the trench runs from east to west, about 1 m deep, 1m wide at the upper mouth, slightly narrow at the bottom, inverted trapezoid in cross section, and the length can be determined according to the storage capacity. After digging a drainage ditch on both sides, let it dry fully, and then put potato pieces. The stacking thickness of the lower potato pieces is about 40cm, the middle is filled with dry sand 15mm~20mm thick, and the upper potato pieces are about 30cm thick and slightly covered with fine sand soil. Set up a temperature measuring tube at a distance of about 20cm from the ground and insert a thermometer. When the temperature drops below 0℃, the ridge shape of the house is thickened in stages, so as not to be frozen through, and the ditch temperature is kept at about 4℃. When the temperature rises in spring, straw, wheat straw and other materials that are not easy to conduct heat can be used to cover the ground to prevent the temperature in the buried ditch from rising sharply.

(4) Ventilator storage The city uses ventilation storage to store potatoes. Tuber pile height should not exceed 2m, ventilation tower should be placed in the pile to cool down in early stage. Can also be loaded basket palletizing, conditional can also be set up in the library special wooden cabinet loaded potato block, in order to ventilate, storage capacity is also large, but the cost is higher.

(5) cold storage has cold storage conditions, can put potato pieces into baskets or wooden boxes, first in the precooling room precooling, until the tuber temperature close to the storage temperature, and then transferred to the cold storage room storage, storage temperature should be maintained at 0℃~2℃ temperature range. When stacking baskets (boxes), appropriate ventilation channels should be left to make the temperature and humidity in the stack uniform. Storage period should be regularly checked, found infected potato block timely elimination, to prevent spread.

(6) Chemical storage It is difficult to obtain low temperature environment in summer and autumn in southern China. After the end of tuber dormancy, the germination loss is serious. Some drugs can be used to inhibit germination. According to reports from Shanghai, Guangdong and other places, methyl or ethyl α-naphthylacetate treatment has obvious bud inhibition effect. 100g ~ 150g/5000kg potato pieces, 7.5kg~ 15kg fine soil powder, sprinkled in the pile, the application time is about the middle stage of dormancy, too late will reduce the efficacy. But it should be sprayed in the field at the stage of potato swelling, and the mass fraction of the pesticide is 0.2%.

(7) Radiation treatment It is reported that irradiation of potatoes with γ rays of 2.06C/kg~3.87C/kg has obvious bud inhibition effect, which is a technique with high bud inhibition effect in storage potatoes at present. The experiment also showed that the higher the dose rate, the more obvious the effect was at the same dose. Generally, the cells still have vitality under the irradiation dose of 12.9 C/kg, and the irradiation dose below 25.8 C/kg can prevent the synthesis of DNA in the growth point cells, change the protein colloid, transform the cell fluid from acidic to alkaline, obviously inhibit the activity of enzymes in mitochondria, and obviously reduce the respiratory intensity of the bud eye.

Potato is easy to rot due to ring rot and late blight during storage. Higher dose of γ-ray irradiation can inhibit the growth and reproduction of these pathogens, but it can also damage potato and reduce its resistance. Inoculation of such tubers with the pathogen results in rapid propagation of the pathogen, but this adverse effect can be eliminated by increasing the storage temperature, since cell lignification and peridermal tissue formation are accelerated at elevated temperatures, thereby reducing the chance of infection by the pathogen.