Molecular Pathogens, 2025, Vol.16, No.3, 87-99 http://microbescipublisher.com/index.php/mp 95 resistance of local sweet potato varieties. For example, in China and South Korea, where sweet potatoes are mostly grown in warm areas, root rot mainly happens during storage. After harvesting, the roots often rot while being stored. In hot and wet years, the infection rate can go up a lot after three months of storage. In some cases, more than 15% of stored roots are lost (Pan et al., 2023). The main reasons are: the sweet potato types grown here are high-yielding but not very disease-resistant, and farmers often use traditional storage cellars that do not have good air flow or temperature control, which makes it easier for fungi to grow. In contrast, in the southern U.S. states like North Carolina, root rot is a problem both in the field and during storage. The popular variety 'Covington' grows well but is not resistant to disease. Farmers use overhead irrigation, and in hot, wet summers, this makes the stems and roots more likely to get infected by Fusarium fungi. This can lead to large field losses (Zheng et al., 2021). In tropical areas of South America and Africa, soft rot diseases are more common. These are often caused by Rhizopus fungi, and they spread quickly if the sweet potatoes are damaged during harvest or transport. But in these places, people often eat or process the sweet potatoes soon after harvest, so the time in storage is short. As a result, Fusarium dry rot causes less damage overall. Different regions face different disease risks, so they need different control methods. In temperate areas, the focus is on stopping dry rot in storage. In tropical areas, farmers must deal with both dry and soft rot. For example, China and Korea should improve storage and grow more resistant types. The U.S. needs to improve field management. In Africa, simple and cheap methods like treating seed roots with biological products can help. Sharing these experiences between regions can help improve global sweet potato disease control. 6.2 Summary of prevention and control practices and results in high-incidence areas For areas with high incidence of sweet potato root rot, various comprehensive prevention and control measures have been adopted in various places and achieved certain results. Take the case of Shandong Province, the main sweet potato producing area in my country, as an example: the local sweet potato is the dominant variety for fresh consumption. In recent years, root rot has significantly worsened in some long-term continuous cropping plots, which once caused a large number of potatoes to rot during storage. To this end, the local agricultural department has implemented a series of comprehensive control measures, including: adjusting the rotation system, adding one year of fallow or intercropping green manure on the basis of the sweet potato-wheat double-cropping system to interrupt the pathogen cycle; promoting the "well-cellar-style" ventilated storage technology of sweet potatoes, by setting ventilation ducts at the top and bottom of the cellar to achieve air convection cooling and dehumidification, and effectively control storage diseases; distributing and demonstrating the use of biological microbial agents, such as Trichoderma agent mixed with soil in the cellar and biocontrol Bacillus subtilis sprayed on the cellar wall, to reduce the content of pathogens in the storage environment. According to statistics from the local plant protection station, after the pilot demonstration of the above measures, the average incidence of root rot of sweet potatoes in the pilot warehouses during storage has dropped by more than 60%, and the storage loss rate has dropped from the original 20% to less than 8% (INNSPUB, 2025). For example, North Carolina, USA, has achieved good results in the comprehensive application of disease-resistant varieties and chemical control for field root rot. They replaced the original highly susceptible ‘Goldrush’ with the moderately disease-resistant ‘Beauregard’ improved variety, and dipped the seedlings in the agent for preventing and controlling black pox in the seedbed (the main ingredient is azole fungicide) when transplanting the seedlings. As a result, the incidence of root rot and stem blight in the field was significantly reduced, and the yield loss was reduced by about 15%. It can be seen that the successful experience of high-incidence areas lies in the coordinated efforts of multiple measures: such as variety replacement + cleaning seedlings + transformation of storage facilities + combination of biological/chemical control measures. 6.3 Case enlightenment countermeasures and their promotion potential The cases of sweet potato root rot prevention and control in various places provide us with valuable inspiration. First, the concept of integrated prevention and control must be implemented throughout. From the experience of
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