What is the reason why wheat seedlings are weak and yellow

Many growers know that it is very common for wheat seedlings to appear weak and yellow, and in some areas, it will lead to large-scale death of wheat seedlings, causing huge economic losses to growers. So what is the cause of weak yellow wheat seedlings? Let's learn about it together with Xiaobian.

1. Straw returning to field with shallow tillage layer

Sowing wheat after returning the straw to the field after corn harvest not only conforms to the law of agricultural production, but also improves the fertility of soil and avoids the pollution caused by burning straw. However, now the amount of corn returned to the field is large, and the tillage layer is generally no more than 20 cm, so that part of the wheat roots are tied to the straw after emergence, so it is difficult to absorb nutrients from the soil, and many people do not have the habit of topdressing in the wheat seedling stage, so it is inevitable that the seedlings will be weak and yellow. Therefore, when corn stalks are returned to the field, they must be chopped up and then suppressed to preserve moisture, so as not to directly affect the nutrition of wheat seedlings, and nitrogen fertilizer should be applied in time.

2. Continuous low temperature freezing injury

In the period of value-added low temperature when planting winter wheat, if the climate changes greatly at this stage, such as rainy days, continuous low temperature, less light time, the overall wheat seedling condition is weak, and affected by low temperature freezing injury, the leaf will directly show yellow. Therefore, it is necessary to strengthen management before the arrival of cold current and spray foliar fertilizer to avoid seedling yellow caused by cold damage.

3. Lack of fertilizer

In the process of wheat growth, if the sowing is too early, the basal fertilizer is insufficient or the nitrogen content in the basal fertilizer is low, it will also lead to nitrogen deficiency yellow of wheat. When the phosphorus fertilizer in wheat basal fertilizer is insufficient or the soil is deficient in phosphorus, it will also cause phosphorus deficiency yellow wheat, which is characterized by few secondary roots, few tillers, dark green leaf color and yellow leaf tip. For nitrogen deficiency, urea 5 kg per mu should be applied in time, and urea 10-15 kg per mu should be applied at the jointing stage of the whole plant; for phosphorus deficiency, 10 kg of diammonium phosphate or 45-50 kg of calcium superphosphate should be applied per mu. If the soil is acidified, the chemical fertilizer applied should be carefully selected. It is recommended to use plant ash or quicklime to improve the soil.

4. Sowing too deep

Under normal circumstances, the suitable depth of wheat sowing is 3-5 cm. If the sowing depth is too deep, even if the wheat seedlings emerge, it is also a Lai seedling. If the climate is dry, the seedlings grown will grow weak, yellow and have few tillers; if it rains, the situation will be more serious, resulting in large areas of dead seedlings. For the land with light disease, we should buy medicine in time to spray, not only to take root and seedling, but also to sterilize, and some dead fields should seize the time to replant.

The above is the introduction of wheat seedling weak seedling yellow, I hope to help you, want to know more related knowledge, please pay attention to us.