How to improve the fine leaf yellow of leek seedlings?

1. Before transplanting or sowing, it is necessary to apply foot fertilizer, especially to pay attention to the application of organic fertilizer 2, to cover the manure before returning to green in spring 3, reasonable top dressing Now that it is autumn, autumn management is very important for leeks. First of all, leeks should be harvested in a timely and appropriate amount to prevent excessive consumption of plant nutrients

The root system of leeks is fibrous root system, there is no main and lateral roots, and there are few root hairs on the root system, resulting in a very weak absorption capacity of the root system. Among the common vegetables, the ability of onion and garlic vegetables with fibrous roots to absorb water and nutrients is much lower than that of vegetables with straight roots such as nightshades and melons.

Therefore, if you want to grow leeks well, you must choose a suitable planting plot with sufficient sunlight. The soil is best loam, the soil layer is rich in organic matter, the tillage layer is larger than 30cm, and the water and fertilizer retention is also good. It has good irrigation conditions and is conducive to irrigation.

The leek seedlings are too fine after many harvests, and the nutrients are not supplemented, which will cause them to be too fine; The yellowing of the leaves is caused by a lack of water, so make sure that the growing soil is moist and permeable.

There may be many reasons why leek leaves are yellow, withered, and dry and thorny. It is recommended that you take the following measures to prevent it:

Reasonable watering: Leeks should be kept moderately moist, but not too wet. Too much water may lead to a lack of oxygen in the roots, which can cause yellowing, dry hearts, dry tips and other phenomena in the leaves. Therefore, you need to control the amount and frequency of watering and avoid overwatering.

Pay attention to the amount and timing of fertilizer use: if there is a long-term lack of fertilizer, it will also lead to yellowing, dry hearts, dry tips and other conditions of leeks. You can spray compound fertilizer or organic fertilizer every 10-15 days in spring and summer, and pay attention to the amount of fertilizer used, not overuse.

Control room temperature and air humidity: The temperature suitable for the growth of leeks is about 15 -20, and at the same time, moderate air humidity should be maintained. Too low temperature and humidity may cause yellowing, withering, dry tips and other phenomena of leaves.

Timely removal of pests and diseases: Leeks are susceptible to pests and germs, such as leaf rot, discoloration, etc., should be removed in time.

I hope you can help you with the above measures, and you can continue to consult me if necessary.

The reason for the yellow leaves of leeks is that the temperature rises in summer, and they need to be watered in time to keep the soil moist and ensure air circulation. In the growing season of leeks, phosphorus and potassium fertilizer is applied once every half month, and when we use too much fertilizer, the concentration is too high, so that there is a fertilizer damage in the leek, resulting in dry tips and yellow leaves. Therefore, when we fertilize, we must fertilize according to the needs of fertilizer.

Do a good job of supplementing the nutrients of leeks.

1. Leek leaves are yellowed with 100 insect powder leeks in the process of growth, it is easy to suffer from the harm of leek maggots, the leaves will gradually turn yellow, and insecticides need to be sprayed in time. In the morning of each day, spray the diluted 100 worm powder solution, water in time, promote the absorption of leek roots, ensure air circulation, and the leek leaves will gradually improve.

Second, the reason for the yellow leaves of leeks Leeks like a warm environment, and when the temperature exceeds 35 in summer, leeks will stop growing. The environment is dry, the air is not well circulated, and bacteria and insect pests breed in large numbers. In summer, you need to water in time to ensure that the soil is in a moist state, and you can sprinkle more water in the leek leaves and air to cool down and moisturize.

The growth of leeks is inseparable from sufficient nutrients, and if the nutrients are insufficient, the leeks will appear yellow leaves. Ensuring the slight acidity of the soil can promote the continuous growth of leeks. In the growing season of leeks, phosphorus and potassium fertilizers can be applied at a frequency of once a month, which can continuously promote the growth of leek leaves, which are not only green but also dense.

Prevention and control methods should be rescued according to the cause:

1.Disease. Mainly blight and gray mold. It can be carried out with the corresponding pesticides**.

Disease prevention and control methods.

1 Crop rotation. The cultivation land and seedling land should choose a plot that has not been planted with onion and garlic vegetables within 3 years.

2 Level the land. Renovate the drainage system in a timely manner, so that there is no water accumulation in the furrow after heavy rain, and the waterlogging pits are eliminated.

3. Cultivate robust plants. If you take cultivation measures such as selecting strong seedlings when planting seedlings, removing diseased seedlings, paying attention to raising roots, not harvesting too much, topdressing after harvesting, and controlling irrigation after summer, the plants can grow robustly.

4 bunches of leaves Before the summer rainfall, the lower yellow leaves should be removed, the green leaves should be pulled up, and tied with horse grass pine to prevent the nine leaves from touching the ground, so that the plants can be ventilated and prevent diseases.

5 pesticide prevention and control from mid-July to early August, use 600 to 800 times of 25% methacryl wettable powder, 500 times of 64% anti-virus alum wettable powder, 0 1% to 0 2% copper sulfate solution to irrigate the roots and stems of plants, or use the above liquid to dip the roots when planting.

Botrytis control methods.

In the early stage of the disease: it is necessary to use 1000 times of 70% methyl tobuzine wettable powder and 50% carbendazim wettable powder 500 times of liquid, plus 1500 times of the liquid of promethexin, 1000 times of 50% of Suclin wettable powder, 50% of the liquid of Pythium 1200, 50% of the gray mold rather than 500 times of the liquid, etc. In addition, if you give the medicine once every 1 week, you can take it twice in a short period of time to relieve the condition.

Severe disease period: 50 ml of mildew can be added to 10 to 15 grams of 40% pyrimecoamine suspension per mu, and then there are about 15 to 20 40% Pythium wettable powder, about 15 kg of water is added, and 800 times of azoxycyclamine can be used once every 3 to 5 days, and the number of sprays is appropriately changed according to the different conditions of the development of the disease. Spraying needs to be used in windless weather, if it rains after spraying, it should be sprayed again after rain, which can also effectively prevent and control gray mold fungus and achieve the purpose of increasing production and income.

2.Pest. Mainly nine maggots and thrips. Timely application of medication.

Nine maggots a, spray 50% phosphine emulsifiable concentrate 800 times or 50% cyanocyanide chloride emulsifiable concentrate 3000 times in the peak stage of adult emergence, and the best effect is applied at 9 to 10 in the morning;

B, in the larval pest period, when the tip of the leaves of nine vegetables began to turn yellow, soft, and gradually lodging to the ground, that is, should be treated with medicine, you can choose to use 50% phosphine emulsifiable concentrate 1000 times liquid or 80% trichlorfon soluble powder 1000 times liquid watering.

Thrips: Irrigate the roots 3000 to 5000 times using 25% thiamethoxam water dispersible granules.

3.Trace element deficiencies can also cause dry-pointed yellow leaves. If there is a lack of calcium, boron, iron, zinc and other trace elements, you can spray sea foliar fertilizer to supplement trace elements and increase nutrients.

1. Improper watering.

Reason: The amount of watering should be controlled, if watering too often will cause too much soil moisture, resulting in root damage, and the leaves will also be a little yellow. If there is a lack of water, the old leaves will appear dry and yellow.

Treatment: When there is too much water, if it is not serious, immediately stop watering and draining. If it causes rotten roots, it needs to be cut off and replanted. If there is too little water, it is necessary to water it in time and replenish it gradually.

2. Excessive fertilization.

Reason: Leeks need limited fertilizer to grow, if too much fertilizer is applied, the root system can not be fully absorbed, burning the root system, causing the leaves to turn yellow.

Treatment: Water the soil to drain excess fertilizer, or rinse the roots, then change the soil and replant. Also, be careful not to use too much acidic fertilizer.

3. Pests. Reason: The main pest of leeks is leek maggots, which are harmful to plants, reducing the absorption capacity of the root system, yellow-brown leaves, and even causing plant death in severe cases.

Treatment method: High-efficiency and low-toxicity insecticides, such as trichlorfon powder, phosphine emulsifiable concentrate, etc., can be used to reduce the harm of leek maggots.

Why do leeks get thinner and thinner? What to do if leek leaves turn yellow? The main reasons why leeks are getting thinner and thinner are as follows:

1。If fertilizer is not applied in time after each harvest, the lack of fertilizer and water will lead to poor growth of the next crop of leeks. The leek leaves will weaken and turn yellow.

If you harvest it too often, the leeks will weaken. When harvesting leeks, it is advisable to harvest 4-6 times a year with 6 leaves as the harvesting standard. If the quality of the leeks is poor, the harvest can be postponed, and the leek stems should be removed in time to reduce nutrient consumption.

3. Root system problems: low ground temperature in autumn and winter leads to fragile leek roots, or maggots destroy the leek root system, resulting in poor nutrient absorption of leek roots, and one crop grows thinner than another.

The more the leeks are cut, the finer the solution will be.

1. Timely top dressing. After cutting a stubble of leeks, you can bury some rotten chicken manure in a ditch and cover it with *. In this way, when watering, the fertility penetrates and the nutrients are transferred directly to the root system of the leek, so that there are enough nutrients to support the continued growth of the leek in the next crop.

In addition, plant ash can be sprayed to add various nutrients to the soil.

2. When the root guard is just cut with leeks, don't pour a lot of water. Too much watering can easily lead to root rot. In addition, if the old roots are forked, the old roots should also be cut off in time, leaving only the new roots for cultivation.

3. Reasonable cultivation * can be carried out within 3-5 days after the harvest of leeks*, generally 2 cm thick sand * can be sprinkled directly on the top, which can promote the continuous tillering of the storage roots of leeks, the growth and development of the root system, and is conducive to the absorption of nutrients.

4. On the one hand, maggot control can timely clean up the remaining branches, dead leaves and weeds on the edge of vegetables, thereby reducing the hatching rate of larvae and the emergence rate of adults. On the other hand, in the adult emergence, 2500 3000 times of low-toxicity pyrethroid pesticide or 1000 times of 75% phoxanthion can be sprayed on the boundary surface, which can directly kill the adult insects. In general, the more chives are cut, the finer they become.

The main reason is mismanagement. Every time you cut a leek, you should promote its rejuvenation. At the same time, do not harvest too often to ensure the quality of the leeks.

It is because the frequency of straightening in the process of growth is becoming less and less, so it will lead to thinner and thinner. It may be that there are some diseases, which can be carried out with some corresponding drugs**, and crop rotation can also be carried out, and more watering and fertilization can be carried out.

It may be caused by a lack of nutrients, we must water more and fertilize more, so that we can better solve the problem, most of the yellowing is caused by a lack of elements.

If each stubble of leeks is not topdressed in time after harvesting, it is easy to cause poor growth of the next stubble of leeks. Leek leaves will become thinner and yellow. Low ground temperature in autumn and winter leads to weak root system of leeks, or maggots damage the root system of leeks, resulting in poor nutrient absorption of leek roots, and one stubble is thinner than the other.

1. Reasons for the yellowing of leek leavesSoil acidificationLeeks prefer neutral soil. If acidic fertilizers such as cake fertilizer, ammonium sulfate, and superphosphate are applied for a long time, it will cause soil acidification, making leeks grow slowly, slender, and yellowish leaves. Harmful gases harm a large amount of ammonium bicarbonate before buckling the shed, spraying urea on the ground after buckling the shed, and applying ammonium sulfate to alkaline soil, which is easy to produce ammonia gas when decomposing, causing ammonia damage, and excessive nitrite accumulation can also cause gas poisoning.

High and low temperature damage When the spraying temperature is above 35 degrees for a long time and the air is dry, it is easy to cause leaf burning. Sometimes, the sudden sunshine after a rainy day, or the sudden invasion of cold air into the high temperature, will make the leeks turn yellow at night or on the whole leaf. In addition to nitrogen, phosphorus, and potassium, the growth of leeks needs a variety of trace elements.

Once these elements are missing, yellow leaves appear. For example, zinc deficiency can lead to new leaves, magnesium deficiency can lead to yellow leaves, and boron deficiency can lead to yellow leaves of the heart. Increase the application rate of organic fertilizer with nitrogen, phosphorus and potassium fertilizer, supplement trace elements, ensure the uniform and sufficient nutrition of plants, according to the characteristics of leek fertilizer, pay attention to the application of nitrogen, phosphorus, potassium and trace elements in the stubble period.

From September to October, or before closing, 50-75 kg of potassium sulfate compound fertilizer can be applied per mu, 10-15 kg of trace elements can be applied, and foliar fertilizer can be sprayed 2-3 times during the growth period. Timely wateringReduce the frequency and amount of watering while ensuring soil moisture in the field. Generally, the watering interval of sandy soil is shorter, and the watering interval of cohesive soil is longer.

After watering, the soil is loosened by tillage and increases soil permeability. The use of high-efficiency and low-toxicity pesticides for insect disease prevention can reduce the harm of leek maggots. Pesticides can be poured every 3-5 days from August to September or before closing.

When the leeks grow to 5-10 cm, apply the round pesticide to the ground. At the peak of the pest, sprinkle trichlorfon powder along the ridges, and sprinkle kilograms per mu. Or use water to dilute the dust to release phosphine and chlorpyrifos, and then irrigate the roots of leeks, the effect is better, and effectively reduce the yellow leaf phenomenon caused by pests and diseases.