What to Do About Yam Variety Degradation? Causes and Solutions

Yam is rich in nutrients and has a fairly wide planting range; it is a crop with extremely high economic value. In recent years its price has remained fairly stable, but during cultivation, yam resistance decreases, tubers become small and mostly misshapen, and yields also drop sharply, seriously reducing its commercial value. This is actually yam variety degradation. What causes yam variety degradation? How should it be prevented and controlled? Let's take a look together.

1. Continuous cropping

Yam has a high demand for soil nutrients. Generally, after one planting, it absorbs the soil nutrients clean, so it cannot be planted continuously; the land needs several years of rest before it can be planted again. Continuous cropping not only causes nutrient deficiency, but also leads to a greater accumulation of pests and diseases. During cultivation, pests and diseases are very easy to breed, among which nematodes are especially serious, causing a severe decline in yield and quality.

Solution: Adopt a reasonable crop rotation method, avoid continuous cropping, and eliminate variety degradation caused by continuous cropping. During sprouting, seeds can be soaked in carbendazim solution for half an hour, then removed and placed in moist sand to sprout, which disinfects and prevents diseases. During the production period, once diseased plants are found, remove them promptly, and pull out the surrounding plants at the same time, then disinfect the diseased holes with lime.

2. Viruses

Viruses are one of the main causes of yam variety degradation. Viruses lurk in the tubers and plants, not only spreading year after year, but also strengthening year by year, causing plant leaves to curl and wrinkle, with fewer green leaves; at a glance, everything looks abnormal. Although the plants will not die, the yield reduction and quality decline are fairly serious.

Solution: Use virus-free tubers and plants for planting. Likewise, before planting, strictly disinfect the seed tubers and plants to kill the carried pathogens. During production, chemical agents can be used in combination for propagation, which can both prevent and control the occurrence of diseases and maintain the superiority of good varieties, preventing variety degradation.

3. Variety variation

This situation is mostly caused by seed tubers. Among the purchased seed tubers, there are a large number of variant seed tubers. These variant seed tubers are mixed among good varieties for propagation, causing variety degradation. These situations mostly occur because the facilities of seed tuber propagation bases are incomplete and the breeding procedures are simplified and not compliant with regulations.

Solution: To avoid this situation, start with the purchase of seed tubers. Select seed tubers through purification and selection of the best, and buy standard excellent seed tubers that are suitable for your own planting, so as to eliminate the problem of variety degradation at the source. At the same time, establishing a sound yam good-variety breeding system is the most effective measure to accelerate the promotion of good varieties, maintain variety characteristics, and prevent variety degradation.

The above is an introduction to the causes and solutions of yam variety degradation. We hope it can help you. If you want to learn more related knowledge, please follow us.