During the storage and storage of sweet potatoes, it is easy to cause a variety of diseases if improper management. To this end, it is necessary to clarify the causes of various diseases occurring during the storage period of sweet potatoes and take corresponding measures to prevent them. I. Symptoms and Causes of Major Diseases of Sweet Potato during Storage 1. Sweet potato freeze injury. Freeze damage of sweet potato is one of the main reasons for storage rot. 1 frost damage symptoms. After the tubers are frozen, they are immersed in the frozen parts and used for extruding with clear water. The inside of the frozen potato block becomes dark and black, forming a hard heart, hard crust, cooking is not bad, and a bitter taste bitter. The rot caused by freezing damage generally starts from the surface of the potato heap. 2 Freezing causes. The first reason was that the harvest was too late and it was frozen outside the pit. The symptoms were not obvious. It began to decay about 15 days after entering the pit. Second, in the middle and later stages of storage, cold damage occurs due to poor cellar or cold and warm conditions, and after the tubers are frozen, they are easily infected by pathogens and cause rot. 2. Sweet potato soft rot. 1 symptoms. After the onset of the potato block, the diseased area was softened, and it was light brown in water. After the skin was broken, it was discharged into a yellow-brown juice with an alcohol taste. The surface of the diseased section grew white cotton-like hyphae and gave birth to gray-black granules. When the environmental conditions are suitable, the condition spreads rapidly and the whole potato can rot for 4-5 days. 2 cause of the disease. High temperature and high humidity are conducive to the occurrence of sweet rot in sweet potatoes. When the dew drops on the potato block at 23-29°C, it is conducive to spread of the disease. When the tubers are frozen and wounded, the bacteria will invade the machine. This is an important factor in aggravating the occurrence of diseases. 3. Dry rot. Dry rot is the main disease during the storage period of sweet potato. 1 symptoms. Occurs at the beginning of harvest and throughout the storage period, and mainly invades the potato. In the early stage of disease, the peels irregularly shrink, and the subcutaneous tissue is sponge brown. In the later period, the surface of the potato skin produces round or irregular lesions, dark brown, slightly concave, and the edges are clear. In severe cases, cellar disease occurs and the loss is serious. 2 cause of the disease. Seed potatoes and soil can carry bacteria. After the pathogen infested sweet potato seedlings, the infected potato seedlings appeared latent in the field, and the pathogens of the sweet potato ripening period reached the potato block through vascular bundles and the disease occurred. The optimal temperature for onset is 20-28°C, and it is not easy to be more than 30°C. 4. Black spot. The storage period of sweet potato is the period with the most serious damage and the largest loss of black spot disease. 1 symptoms. After the germs were infiltrated, there was a plaster-like black-black spot on the tuber, which penetrated deeply into the potato meat and was bitter. When the damp spot appeared gray mold layer, after the black puncture, the diseased potatoes unbearable. 2 cause of the disease. Both the potato block and the residue in the old cellar can carry the bacteria. The pathogenic bacteria invade the potato block through the wound. The optimal temperature is 25-28°C. The high temperature and high humidity, especially when there are water droplets on the tuber, will facilitate the spread of melasma. Second, disease control 1. Timely harvesting, timely access to the pit. Into the cellar sweet potato generally in the local average temperature of about 14-15 °C, before the harvest is appropriate to reduce frost, to avoid freezing the potato, reduce the chance of germ infection. 2. Potato cellar processing. Before entering the cellar, clean and clean the old cellar, or shave the cellar walls. The old cellar that developed last year can be fumigated with antibacterial agent “401†or “402†or sulfur. After two days of sealing, open the cellar to fully ventilate. reuse. 3. Pick potato chips. When entering the pit, select healthy potatoes, remove diseased potatoes, damaged potatoes, and frozen potatoes to reduce pathogen infection. When harvesting, transporting, and storage, take care to prevent potato chips from being damaged. 4. Disinfection of tubers. After the tuber is selected, use 50% thiophanate-methyl WP wettable powder 500-700 times, or use 50% carbendazim wettable powder 500 times, soak the tuber l-2 times, and dry it in time. cellar. 5. Strengthen the management of potato pits. After the sweet potato enters the pit, it is necessary to strengthen the management of temperature, humidity and ventilation in order to achieve the purpose of safe storage. One is the initial period of entering the cellar (into the cellar within 15-20 days). At this time because of the large water content of the potato block, strong respiration, the outside temperature is relatively high, so we must open the cellar mouth to ventilate and reduce moisture. If it is not ventilated for a long period of time, the concentration of carbon dioxide in the pit increases, and the tiling is perishable. The second is the middle of storage (20 days into the cellar to February of the following year). This is the critical period of management. Due to the cold weather, insulation should be the mainstay. To this end, the cellar should be sealed. If necessary, cover the straw with wheat straw and other insulation. Keep the temperature at 10-14°C to prevent the temperature from becoming too high. Block germination, the temperature is too low to cause frost damage. Humidity is between 85% and 90%, so as to prevent the humidity from spreading too much, and the humidity is too small. The third is the late storage (after March of the following year). At this time, the temperature of the outside world has risen. The focus of management is on cooling and cooling to avoid temperatures above 15°C. Physical Therapy Equipment,Therapy Medical Device,Physio Therapy Equipments,Shock Wave Therapy Devices Puyang Degren Medical Equipment Co., Ltd. , https://www.degrenyuwei.com
To prevent the main diseases of sweet potato during storage