Why are sesame seeds afraid of repeating?

"Sesame is afraid of repeated cropping, it is blind for ten or nine years" and "stubble is like being fertilized." it can be seen that sesame is the most avoid continuous cropping and generally implements a three-year rotation system, and it is suitable for sorghum, corn, wheat and millet in the first stubble. There are two main reasons for the failure of continuous cropping of sesame seeds: one of the reasons is that continuous cropping of sesame seeds will aggravate the disease. In the process of sesame production, many pathogenic bacteria, such as stem wilt, bacterial wilt, blight and so on, remain in the soil after sesame harvest. If sesame seeds are planted in the second year, these pathogens will become the source of infection of sesame seeds. The longer the continuous cropping, the more pathogens in the soil, and the disease of sesame will become more and more serious. Infected by the disease, sesame plants will appear stunted, single plant dwarf, falling flowers and few capsules and other symptoms, and even a large area of wilting and death will occur. The second reason is that sesame is a crop that needs more fertilizer, continuous cropping will lead to nutrient imbalance, break the balance of soil fertility, resulting in the lack of nitrogen and potassium, and it is difficult to increase the yield of sesame. Therefore, continuous cropping of sesame seeds is unscientific and should be avoided.