What to do if sunflower seedlings turn yellow? What causes the leaves under sunflowers to turn yello

Water yellow. The new leaves of the sunflower plant are dark yellow and dull, the branches are small yellow-green, and the growth is slow, but there is no obvious change in the old leaves, indicating excessive watering. At this time, the watering should be controlled, the plants should be depotted, and they should be dried in a cool place before replanting. Be careful not to damage the mounds of the root system when depotting.

Dry yellow. If the plant turns yellow due to lack of water, the leaf tips and the bottom of the leaves are the first to dry up and dry, and the plant turns yellow from the bottom up, but the new leaves grow normally. It's easy to solve, just water! However, do not pour too much water at one time, make sure to water thoroughly, and the soil is moist.

Lack of light yellow. Many plants can burn their leaves due to too much light. But sunflowers, on the other hand, need plenty of sunlight during their growth.

If it is placed in a shaded environment for a long time, the leaves will not see light, and the whole leaves will turn yellow and fall off. Put the plants in the sun, lack of light, you can use fluorescent lamps to fill the light.

Fat yellow. Sunflowers have a well-developed root system and can penetrate deep into the soil to absorb nutrients, so they do not need thick fertilizer. Excessive fertilization or concentration can cause yellowing of the leaves.

Usually the fat leaves are dull and uneven, accompanied by the shedding of old leaves. At this time, the fertilization should be stopped immediately, and the fertility of the soil should be washed with appropriate watering. The most effective way is to sprinkle some radish and cabbage seeds around the plant to allow them to absorb nutrients from the soil.

Lack of fat yellow. Lack of fertilizer is the starvation of the plant, which is manifested as a small pot with large seedlings, dense fibrous roots in the pot, and dark yellow flowers and leaves. At this time, it is necessary to change a large pot, cut off the old leaves of the plant, and change the soil in time if there is a phenomenon of dry knots.

Usually pay attention to the diligent application of thin fertilizer, and you can spray some pica amino acid foliar fertilizer in an appropriate amount.

Sunflowers have a very high demand for sunlight. If there is enough light, the leaves still turn yellow, then it must be the accumulation of a large number of metabolites in the cells after a certain period of physiological activities, such as minerals, causing the decline of physiological functions and death (chlorophyll destruction). It is recommended that you buy a bottle of chlorophyll supplement nutrient solution on **, which is very cheap.

The little aphid-like insects you are talking about will not make the leaves yellow1 3 so much ......Watering flowers to see dry and wet, watering thoroughly, and then waiting for dry watering, each spray a little, the surface is wet, the root may be very serious, and the pot is too small, not suitable for planting sunflowers, even if it is ornamental sunflowers, the root system is also very developed. You need a larger pot, and if the leaves are yellow, spray carbendazim 1000 times solution, whether it is a lot of water or exposure to the sun or the yellowing of the leaves caused by bacterial infection.

When the seedlings turn yellow, you can add some base fertilizer next to the seedlings! It is also a compound fertilizer, far away from the seedlings, otherwise, you can use some foliar fertilizer.

The causes of yellowing of sunflower leaves and the solutions are as follows:

1) Water yellow: the young leaves are pale yellow, and the old leaves are also gradually darkened yellow. The reason is that the water has been wet for a long time, the soil is hypoxic, and some fibrous roots are rotten. Watering should be controlled and fertilization stopped.

2) Fat yellow: the new leaves are thick and shiny, but the leaf surface is uneven, and the old leaves are yellowing and falling off. This is due to over-fertilization. The fertilizer should be stopped immediately, watered more appropriately, sprinkled some radish or cabbage seeds into the pot, and removed a few days after the emergence of seedlings to consume the excess fertilizer in the pot.

3) Dry yellow: the top center and new leaves are normal, and the lower part of the plant and the inner part of the leaves are dry and yellow first. The reason is that the potted flowers are dehydrated due to long-term lack of watering.

It should be watered in moderation to keep the potting soil moist up and down. The small seedlings in the hungry yellow pot are large, the fertilizer and water are insufficient, the fibrous roots in the pot are dense, the soil is very little, and the flowers and leaves turn yellow.

4) Shade yellow: Because potted flowers are placed in the shade for a long time, the light is insufficient. Sunflowers need strong light, and if the light is too weak or they do not see light for a long time, they will fall and the leaves will turn yellow.

Sunflowers can be planted in all seasons, mainly in summer and winter. The flowering period can be more than two weeks. The growth of sunflowers is proportionate and agile, and the flowering period can be more than two weeks, and the growth of sunflowers is closely related to factors such as temperature, moisture, light, and soil.

1) Temperature. Sunflowers are native to the tropics, but they are more adaptable to temperature and are temperature-loving and cold-tolerant crops. Its seeds are very resistant to low temperatures, and the local temperature is stable, and the seeds begin to germinate above 2; 4 5 times, the seed can sprout and take root; When the ground temperature reaches 8 10, it can meet the needs of seed germination. The optimal temperature for germination is 31 37 and the maximum temperature is 38 44.

Sunflowers can grow normally as long as the temperature is not lower than 10 during the whole growth process. In the appropriate temperature range, the higher the temperature, the faster the development.

2) Moisture. Sunflowers are tall plants with many and dense leaves, making them water-intensive crops. It absorbs twice as much water as corn. However, because its growth and development are mostly synchronized with local rain and heat, the contradiction between water supply and demand is not prominent.

The water requirements of sunflowers vary greatly among different growth stages. From sowing to budding, it is relatively drought resistant and does not require much water, only the total water requirement. Proper drought is conducive to root growth and enhances drought resistance.

From budding to flowering, it is the peak water demand, which accounts for about 43% of the total water demand. The lack of water during this period has a great impact on production. This stage coincides with a lot of rainfall, which can basically meet the water needs of sunflower growth and development.

If it is too dry, it needs to be replenished with irrigation. It also requires more water from flowering to maturity, accounting for about 38% of the total water volume. If the moisture is insufficient, it will not only affect the yield, but also reduce the oil content.

3) Lighting. Sunflowers are short-day crops. But it is not very sensitive to sunlight. For example, under the sunshine conditions of Tianjin, it can bloom and mature normally without special treatment.

Sunflowers prefer full sunlight and have strong phototropism in their seedlings, leaves, and flower discs. Sufficient sunshine and strong seedlings can prevent growth; Sufficient sunshine in the middle stage of growth can promote the vigorous growth of stems and leaves, normal flowering and pollination, and improve the seed setting rate. In the later stage of growth, the sunshine is sufficient, and the seeds are full and full.

Hello dear, 1Improper watering and lack of water often cause sunflower leaves to turn yellow and wilt, and prolonged lack of water can cause sunflower plants to die. Workaround:

Watering the sunflower in moderation and placing it in a cool place, its leaves will fall naturally, and when the sunflower grows new leaves, it will be able to receive light. When the weather is hot, water twice a week, and the sunflower stove will slowly come back to life. 2.

Lack of light Sunflower is a light-loving plant, in the growth period to get enough light, long-term placed in a cool place, very easy to appear leaf yellowing and wilting. Solution: Because the sunflower has less sunshine time in the early stage, do not expose it directly to the sun.

Gradually increase the amount of light to avoid burning the shoots. When the sunflowers return to normal, they can bask in the sun every day.

Lack of light. Sunflower is a very light-loving plant, seedlings, leaf type Qi roll and flower disc have strong phototropism, need sufficient sunlight during growth, if placed in a shaded environment for a long time, the leaves see insufficient light, photosynthesis can not be carried out smoothly, it is difficult to synthesize nutrients, the whole leaf yellowing, falling off. Buyu sunflowers should be planted in a sunny place, and the things that block the sun should be removed, and if the natural light is insufficient, the fluorescent lamp can be used to fill the light.

Sunflower precautions.

Sunflowers are propagated by seeds, and peat soil is preferable for sowing. Before sowing, the new high-fat film is used to dress the seeds, which can repel the pests under the ground boys, isolate the virus infection, and improve the germination rate of seeds. Sunflowers have a high demand for light and a wide range of temperature tolerance.

Soil: Sunflowers are not strict on soil and can grow on all kinds of soils, from fertile soils to dryland, barren and saline-alkali lands. It has strong salt and alkali resistance.

If the sunflower lacks nutrients, it will cause a lack of fertilizer yellow, the leaves are dark yellow, and the sunflower is too much fertilizer or too concentrated, which will lead to root burning, the leaves are dull, uneven, and the old leaves fall off. If the sunflower lacks fertilizer, you can pay attention to the thin fertilizer applied frequently, if the sunflower fertilizer is too much, stop fertilizing immediately, and water and rinse appropriately.

Sunflower Planting Management:

First, timely top dressing.

Sunflower is a plant that needs more fertilizer, partial application of a certain fertilizer or only a certain kind can not meet the needs of sunflower flowering, timely top dressing is very necessary, generally before sunflower buds. Top dressing is used to green water-soluble fertilizer, which can be applied in furrows or holes, generally applied at 10 cm to 15 cm at the root, but nitrogen fertilizer should not be applied in the later stage of sunflower growth, because it may cause a reduction in yield.

2. Scientific watering.

Sunflowers not only need a large amount of fertilizer, but also a large amount of water, growers should replenish water in time according to the weather, soil and the growth of sunflower plants, but do not carry out large watering, after watering, they should also be cultivated in time to loosen the soil, so as to avoid soil compaction and water evaporation.

3. Prune and prune in time.

Sunflowers will grow excess branches during the flowering period, in order not to consume too much nutrients, farmers should remove the branches in time, usually the earlier the better. Between budding and flowering, it is generally done two or three times in a row.

4. Artificially assisted pollination.

Sunflowers are typical cross-pollinating crops that rely mainly on bees and insects for pollination. In the case of insufficient bee sources and insects, artificial assisted pollination should be used to improve the pollination and seed setting rate of sunflowers. Artificially assisted pollination should be selected at about 9 a.m. after the dew subsides to before 12 o'clock when the pollen grains are more and the vitality is vigorous, generally 2-3 times in a row, the first time in the flower disc when half of the flowers are open, the first.

2. The third time is when the flowers of the flower plate ** are open. This can greatly reduce the empty shell rate, increase the fullness of seeds, and increase the yield of sunflowers.

There are two methods of artificially assisted pollination: one is the pollen beat pollination method, that is, the cardboard is cut into a disc as large as the flower plate, the cotton wool is paddled to make the ** part slightly convex, wrapped with flannel or gauze, and a handle is tied on the back to make a pollination puff, when pollinating, hold the pollination puff with pollen in one hand, hold the flower plate with one hand, press the flower plate with the pollination puff and gently pat it a few times, so that the pollen can fall on the stigma; The second is the flower disc contact method: that is, in the full flowering period of the sunflower, the two adjacent flower discs "face to face" are gently rubbed a few times to achieve the purpose of mutual pollination.

1. Insufficient light:Sunflowers love light, and if they lack light, if they are left in a shaded environment for a long time, insufficient light will cause yellow leaves.

2. Improper watering: Sunflowers need to be watered appropriately, once the watering is insufficient or too much watering, it will lead to yellow leaves.

3. Improper fertilization: long-term insufficient fertilization or fertilizer damage will also lead to poor growth and yellow leaves.

4. Pests and diseases: After sunflowers are infected with pests and diseases, they will also cause yellow leaves.

Sunflower precautions.

Breeding potted sunflowers should pay attention to the appropriate fertilizer water, watering to follow the principle of "dry and wet", sowing to budding can maintain slightly dry soil, which is more conducive to the growth and development of sunflower roots, but in the flowering period of the plant to add enough water. During the growth period, nitrogen fertilizer needs to be applied once every 7 to 10 days, and phosphorus and potassium fertilizer should be applied after budding.

Sunflowers are very sensitive to sunlight and need plenty of light for their plants to grow healthier. If it is exposed to rainy days or a shady environment for a long time, sunflowers will have drooping leaves and yellow-green color. And the most suitable temperature for sunflower growth is 18 30, the minimum temperature shall not exceed 10, and when the temperature is higher than 25, pay attention to ventilation.

1.The cause of yellowing and wilting of sunflower leaves.

As a very popular summer ornamental plant, sunflowers encounter various problems during their growth. One of them is the yellowing and wilting of the leaves. For this to happen, in general, there are several reasons that can lead to:

Lack of water. Undernutrition.

Pest. Over-irradiation.

2.What to do if sunflowers are short of water?

Lack of water is a major cause of yellowing and wilting of sunflower leaves. Therefore, staying hydrated** is the key to solving the problem. In the summer, sunflowers need plenty of water every day, so they should be watered every day.

If you observe that the leaves have started to turn yellow, it means that the plant has been dehydrated for some time. In this case, you need to increase the number of times you water the plants and, if necessary, make appropriate changes to the watering method.

3.What about nutritional deficiencies?

Sunflowers need adequate nutrients to grow properly. If your sunflower is deficient in nutrients, its leaves will appear yellowing. To avoid this, you need to increase the nutrients of sunflowers**.

You can add some nitrogen, phosphorus, and potassium fertilizers to the plants to ensure that the plants can get enough nutrients. However, it is important to note that excessive fertilization can also have a negative impact on sunflowers. Therefore, if you are not sure how much fertilizer you should apply, it is best to consult a professional.

4.How to deal with pest and disease problems?

Pests and diseases are also one of the reasons why sunflower leaves turn yellow and wilt. If you notice that your sunflower leaves are turning yellow and you also notice signs of pests and diseases, then you need to take timely steps to protect the plant.

The best way to do this is to use organic pesticides or fungicides to help address pests and diseases. At the same time, you can also turn up the soil to completely remove the pests and diseases. It is also important to inspect the plants regularly and identify problems in a timely manner so that necessary interventions can be made before the problem becomes more serious.

5.How to prevent sunflower overexposure?

The best environment for growing sunflowers is in a sunny and well-ventilated area. However, if the sun shines too much, it can cause damage to the sunflowers.

So, if your sunflower leaves become wilted and you suspect that it may be due to excessive exposure, you need to keep the plant away from the scorching sun and provide proper shade if necessary. If you're planting potted sunflowers, you can move them to a more suitable location.

6.Conclusion: Sunflower is a very beautiful plant, but it is prone to encounter various problems in the process of growth.

In order for sunflowers to grow healthily, we need to identify problems in time and solve them in time. For the causes of yellowing and wilting of sunflower leaves, we can protect the plants by replenishing enough water, nutrients, chemicals, and strengthening the prevention of pests and diseases. Only then can we have a thriving sunflower!