Sesame is a very good oil crop. The sesame oil is fragrant, nutritious, and has certain health care functions. Therefore, in recent years, the demand for sesame has increased and the area for planting sesame has expanded. When cultivating sesame, there is a problem that must be paid special attention. In other words, the last year had been planted with sesame seeds, and the second year could not be planted. Otherwise, it will not achieve high output and high efficiency. There are two main reasons why sesame can't be grown continuously: One of the reasons is that sesame seedlings can make the disease worse. In the process of sesame production, many pathogenic bacteria such as stem blight, bacterial wilt, and epidemic diseases are left over in the soil after sesame harvesting. If the sesame seeds are replanted the next year, these pathogens will become the source of infestation of sesame seeds. The longer the re-tanning time, the more pathogenic bacteria will be in the soil, and the diseases of sesame will become more and more serious. Affected by the disease, sesame plants will appear to be stunted, single plants dwarf, less flowering and other diseases, and even a large number of death will die. The second reason is that sesame is a crop that requires more fertilizer, and even planting can cause malnutrition. According to the test, for every 50 kg of sesame produced, 4.50--5 kg â€‹â€‹of nitrogen, 1.25 kg of phosphorus pentoxide and 5-5.50 kg of potassium oxide are required to be absorbed from the soil. The ratio of three elements is approximately 4:1:4.40. It can be seen that sesame requires more nitrogen and potassium and less phosphorus. If it is planted, it will break the balance of soil fertility, resulting in a lack of nitrogen and potassium, making it difficult to increase sesame yield. Therefore, sesame seedlings are unscientific and should be avoided.