How to manage frequent Fusarium wilt in Chinese yam during the rainy season?

    After entering the rainy season, the following tasks should be done well in Chinese yam management:

Chinese yam

    1. Reasonable chemical growth regulation:

    The rainy season brings high temperatures and humidity, and combined with topdressing, this makes Chinese yam grow excessively vigorously. Therefore, before entering the rainy season, chemical growth regulation must be carried out, and it is better to do it early rather than late. When the Chinese yam vines climb to 2/3 of the trellis surface, it should begin. Spray each mu of Chinese yam with 50 g PBO + 10 g Ruipeile. According to the vine growth, spray about once every 15 days, for 2—3 consecutive sprays. In this way, the Chinese yam stems and leaves can be strong but not overgrown, controlling the top and promoting the bottom, balancing the growth of the aboveground and belowground parts, and obtaining a higher yield.

    2. Improve the soil to promote rooting:

    The downward growth of Chinese yam roots and tubers has strict soil requirements. It must be sandy loam soil, and the soil must not be too heavy. Plots with continuous cropping year after year or poor soil quality must be improved. For each mu of Chinese yam, use 1 kg Ciba soil loosening essence, mix with 20 jin of fine soil or fine sand, and broadcast it into the beds to loosen the soil and promote smoother downward growth of the Chinese yam tubers, increasing the marketability of Chinese yam while also increasing yield.

    3. Apply medicine and fertilizer together to prevent vine death:

    By the end of June, Chinese yam tubers enter the enlargement stage. During this period, the demand for water and fertilizer is greatest, but because of the rainy season, the problem of Chinese yam Fusarium wilt, that is, dead vines, becomes serious. Therefore, it is necessary both to topdress and to prevent vine death. For each mu of Chinese yam, apply Ruimiaoqing 200 ml + Chongshi Banlv 1.5 kg by flushing with water. While preventing disease, it replaces topdressing, so no other fertilizer is needed. For plots with severe Fusarium wilt in previous years, apply another flush at the end of July, which can effectively prevent Chinese yam vine death.

    4. Control diseases to ensure high yield:

    The most serious underground disease occurring in Chinese yam during the rainy season is Fusarium wilt, that is, dead vines. It is a typical continuous cropping disease. The longer the continuous cropping years, the more severe the incidence. Once it occurs, there is no way to deal with it, so it can only be prevented. First, flush with Ruimiaoqing 200 ml/mu + Chongshi Banlv 1.5 kg. Second, in particularly severe cases, focus on spraying and drenching the root and stem area of Chinese yam with Ruimiaoqing 8 ml/bucket of water + Yiwei 20 g/bucket of water, which can reduce the occurrence of the disease.

    5. Foliar fertilizer supplementation is indispensable:

    After Chinese yam enters the rainy season, foliar fertilizer supplementation is indispensable. In the early stage of tuber enlargement, spray Ruipeigai 20 g/mu to prevent necrosis and forking of Chinese yam tubers. In the middle stage of tuber enlargement, spray Biou 30 ml/mu + Ciba potassium dihydrogen phosphate 50 g/mu to increase yield and prevent premature senescence.