Key points for high-yield yam management: scientific fertilization, disease control, loose soil

    Doing a good job of several key links in yam production management will greatly increase the economic returns of yam cultivation. In yam cultivation management, the focus should be on applying base fertilizer, keeping the soil loose, treating the yam seed, timely topdressing, and disease control, and taking measures to promote the growth of the yam root tuber as much as possible.

Yam sowing

    1. Loose soil is good, and tubers expand easily.  

    Loose soil is crucial to root elongation and expansion. The planting trench should be dug to a depth of about 1 m. Sandy loam is loose and airy, warms up quickly, and produces good early seedling growth, which is favorable for yam tuber elongation; heavy clay soil is cold and hard with poor aeration, which is unfavorable for root elongation, but it has strong residual fertility. Regardless of soil type, more than 1000 kg of cow or horse manure or crushed crop straw (wheat straw or rice husks also work) can be mixed in per mu, which can both increase soil organic matter and improve soil permeability. Large stones, bricks and tiles, and gravel in the soil should be removed to avoid damaging the root tuber. It is best to dig the trench before the soil freezes, which is favorable for weathering the soil and producing a good soil structure. The earlier irrigation is done, the better, so as to raise the ground temperature as early as possible.  

    2. Base fertilizer must be applied in sufficient amount, and plastic film should be used as mulch.  

    Apply more than 3000 kg of decomposed chicken or duck manure or pig or sheep manure, more than 50 kg of potassium sulfate compound fertilizer, and about 50 kg of diammonium phosphate per mu as base fertilizer. If conditions permit, add 100 kg of biological bacterial fertilizer and soybean cake fertilizer, and 1 kg each of boron, zinc, and iron micronutrient fertilizers, mix thoroughly with the soil, and fill it into the planting trench. After irrigating thoroughly, sow only when the ground temperature rises to 15°C. After sowing, plastic film should be used as mulch to raise temperature and preserve moisture. The film should be removed at the end of May to facilitate the downward growth of the root tuber. 

 
    3. Seedlings must be treated to prevent both disease and insects. 

    After sowing, yams are prone to infection by root rot and damping-off, and the simplest method is to treat the yam seed. The yam seed can be soaked in 1000 times fludioxonil (Celest) or 1500 times azoxystrobin, and after spraying the pesticide along the trench, sow again to ensure that yam seedlings do not die during the seedling stage.  

    There are many underground pests in spring, mainly mole crickets, wireworms, white grubs, and cutworms. A relatively effective method is to spray 1500 times phoxim along the trench. Or use high-concentration thiamethoxam (Ruice) sprayed into the trench to control underground pests, with better results and higher safety.  

    4. Protect stems and leaves in the mid-term, with three points to note.  

    In the mid-growth period of yams, there are many rainy days and high humidity, which easily trigger anthracnose, brown spot disease, Cercospora leaf spot, brown rot disease, and viral disease. Azoxystrobin at 1500 times plus copper hydroxide at 600 times can be sprayed, once every 15 days, for 2-3 sprays. For brown rot disease, the above method can be used to drench the roots, especially after heavy rain. For viral disease, focus on controlling whiteflies and mites. Pay attention to topdressing chemical fertilizer; in the mid-growth period, topdress 2-3 times, applying about 25 kg of potassium sulfate compound fertilizer per mu each time. Pay attention to removing yam beans in time to reduce nutrient consumption.