What are the causes of uneven watermelon seedlings and prevention and control methods?

There are many reasons for the uneven seedlings of watermelons, the first of which may be due to improper temperature. Watermelon is a heat-tolerant crop that requires high temperatures throughout its growth and development. It has been observed that the minimum temperature required for watermelon growth is 10, the maximum temperature is 40, and the optimal temperature is 25 30.

If the soil temperature is too low, it will affect the development of watermelon roots, and the nutrition can not meet the needs of the normal growth and development of melon seedlings, and the phenomenon of uneven watermelon seedlings will occur.

The seedbed is compacted and has poor air permeability, which can cause insufficient oxygen content in the soil, resulting in slow growth of the embryo and delayed germination. At the same time, the compaction of the seedbed will also increase the difficulty of the top soil of the seed bud, which will cause the phenomenon of slow seedling emergence and the formation of uneven watermelon seedlings.

The amount of fertilizer is large and too concentrated, so that the root system can not be rooted or burned, and the fertilizer water cannot be absorbed and the growth is affected; Or the base fertilizer is too deep, and the upper layer of fast-acting fertilizer is insufficient, and the seedlings will be uneven. In addition, watermelon likes moisture, is drought-tolerant, not waterlogging, and the soil moisture is too large, resulting in roots, unable to absorb nutrients, and naturally grows slowly; Or the soil is dry, which can not meet the water and fertilizer of the plant, which will also cause the appearance of uneven seedlings.

In addition, the humidity and temperature of the seedbed are high (especially the night temperature is high), the amount of available nitrogen fertilizer is too large, the light is insufficient or the spacing between melon seedlings is small, which will cause watermelon to grow, which is also a kind of uneven watermelon seedlings.

Watermelon root nematode is also one of the causes of uneven watermelon seedlings, watermelon root nematode only damages the roots, especially the tender parts of the root system (lateral roots and fibrous roots). The roots that are harmed by the root nematode will grow nodules of different sizes and shapes, which hinders the absorption of nutrients and water by the roots. Not only that, the root nematode will form a wound when it is harmed, and a large number of germs will invade from it and harm the root nematode together.

Therefore, watermelon seedlings that are harmed by root nematodes will not only have uneven seedlings, but also die seedlings in serious cases.

As for the methods to prevent uneven watermelon seedlings, the main points are as follows. 1. Select high-quality (disease-resistant) seedlings and disease-free soil for sowing, and disinfect the seedbed before planting. 2. Scientific sowing, strengthen field management, increase the application of fully decomposed organic fertilizer, improve the content of organic matter in the soil, promote the growth of new roots, and enhance the disease resistance of plants.

To prevent the seedbed from compaction, it is necessary to water the bottom of the foot, not to water or less water during the seedling period, and to prevent rain in the rainy season. 3. Plough the soil before planting, and the fields with severe soil-borne diseases can be rotated with water and drought. 4. To prevent watermelon root nematodes, farmers can use Yinghui lineicide Ligansha granules to apply in ditches, holes or whole fields before watermelon transplanting.

If the watermelon is damaged by nematodes during the growth period, irrigate the roots with a blue root sand solution (blue root sand + Tian Lijian) mixed with water.

After returning to the soul, the old abbot is still the identity of Shen Gongzi, but his temperament has changed greatly, accumulating virtue and doing good, often closing his eyes and chanting, and finally running away from home, returning to Changqing Temple, holding up the tile bowl, and then being the host.

1. Low temperature freezing: watermelon seedlings are suitable for growing in an environment of 10-15 degrees, and the seedlings will not grow after freezing. 2. Suffering from waterlogging:

Frequent watering at the seedling stage leads to watermelon seedlings rotting and not growing roots. 3. Blind fertilization: apply thick fertilizer and raw fertilizer to watermelon seedlings, resulting in root burns.

4. Poor soil quality: the use of clay heavy soil planting affects growth.

1. Low temperature freezing

The suitable growth temperature of watermelon seedlings is between 10-15 degrees, and the temperature is lower than 10 degrees, which will lead to the seedlings being frozen, limited growth, and the phenomenon of stiff seedlings and not growing.

2. Suffering from waterlogging:

Watermelon in the process of growth of nutrients demand is larger, but the seedling stage of the root system is not developed, not tolerant to waterlogging, at this time watering too much water, will reduce the oxygen content in the soil, affect the fundamental respiration, resulting in watermelon seedlings do not grow, need to loosen the soil in time to drain, keep the soil dry.

3. Blind fertilization

Watermelon seedlings need to be fertilized, but blindly make Bu Li with raw fertilizer, unrotted farm fertilizer, thick fertilizer, will lead to fertilizer damage and stiff seedlings, can not grow normally, so when breeding watermelon in the seedling stage, it is necessary to apply rotten farm fertilizer or nitrogen fertilizer with water.

4. The soil quality is too poor

Watermelon is a shallow root crop, suitable for growing in loose soil, good drainage of sandy soil, planting the use of compacted, clay soil, will affect the growth of the root system, the phenomenon of not long, at this time to replace the watermelon with suitable soil replanting.

What are the methods for the prevention and control of seedling diseases by grafting watermelon seedlings, and what pesticides can prevent and control diseases?

The seedling stage of grafted watermelon seedlings is prone to diseases, and the following are the control methods and available pesticides:1Reasonable fertilization, maintaining suitable humidity, cultivating healthy seedlings, and strengthening seedling management can effectively prevent diseases.

2.Pay attention to ventilation and ensure that there is enough sunlight to prevent the growth of germs. 3.

The watering method is used to avoid drenching leaves and roots, and the incidence of diseases is reduced. 4.Regularly clean up diseased strains to reduce the pressure of infected germs.

5.The use of disease control agents, such as propiconazole and other broad-spectrum fungicides, sulfur and other disease prevention and control agents, can be sprayed on grafted melon seedlings for disease prevention and control. However, care should be taken to follow the instructions for proper use to prevent drug poisoning and residue problems.

6.Various melon seedlings with high resistance varieties are selected for grafting to enhance the disease resistance of plants and reduce the occurrence of diseases. Sensitivity and tremor.