What is the reason for cucumber yellow leaves? How can it be alleviated?

It could be that the soil is too dry, it could be a lack of fertilizer, it could be a lack of light, it could be that too many drugs are being used, or it could be that the soil is poor. Be sure to pay attention to the external environment, avoid the temperature being too low, and also pay attention to the appropriate reduction of watering amount.

It could be a lack of water, it could be a lack of organic fertilizer, it could be a lack of light, it could be malnutrition. At this time, we must find the root cause of the problem, we must prescribe the right medicine, and we must actively carry out top dressing.

If it is caused by malnutrition, or because of the planting environment, it is necessary to pay attention to light and watering.

Cucumber yellow leaves are because of the shed without excessive watering, improper fertilization, disease caused, the amount of watering each time is not too large, if watering more to drain in time, cucumber fertilizer damage, need to be watered immediately, in addition, when using fertilizer should also pay attention to nutritional balance, cucumber disease, to spray in time**, but also as soon as possible to cut off the branches and leaves of diseases and insects.

Cucumber yellow leaf cause.

1. Overwatering:If the soil is not breathable, there will be water accumulation after watering, so that the roots are soaked in water, and there is a lack of oxygen, then the leaves will be yellow.

2. Improper fertilization:When fertilizing cucumbers, we must pay attention not to apply fertilizer with too high concentration, otherwise it is easy to burn roots, which will lead to yellowing of cucumber leaves, and potassium deficiency during growth, the old leaves of cucumbers will be yellow, lack of iron and calcium, and the young leaves of cucumbers will turn yellow.

3. Occurrence of diseases:Cucumber leaves appear yellow, first of all, you need to observe whether there is a problem with the roots, such as infection with wilt, root rot, etc., cucumber leaves will be yellow, secondly, cucumber downy mildew, horn spot and so on will also cause leaf yellowing, this time need to be timely symptomatic**.

Treatment method for yellowing cucumber leaves.

1. Control wateringIf the cucumber is overwatered, you must pay attention to the drainage work, the amount of watering each time is not too large, if this happens, you can use some rooting agents to promote root recovery.

2. Reasonable fertilizationCucumber fertilizer damage, need to be watered immediately, so that the concentration of fertilizer in the soil can be diluted, in addition, when using fertilizer, we should also pay attention to nutritional balance, timely replenishment of potassium, iron, calcium.

3. Disease prevention:If cucumber is diseased, it is necessary to spray in time**, and cut off the branches and leaves of diseases and insects as soon as possible to reduce the spread of bacteria.

Cucumber and yellow leaf control.

Cucumber likes warm, the temperature suitable for growth is between 25 -32, during the growth period can be watered appropriately, watering once every 3-5 days, cucumber planting needs to be applied enough base fertilizer, during the growth period need to continue to top dressing several times, mainly to the silver fertilizer.

1. Element-deficient yellow leaves.

Element-deficient yellow leaves can be divided into two situations: middle and lower old leaves first yellow and middle and upper young leaves first yellow. The middle and lower leaves are yellow, and the missing elements are mostly the elements that are easy to be reused in the plant, such as nitrogen, potassium, magnesium, zinc, etc. (1) The growth of the whole plant is resisted, and the whole leaf lacks green first, which is nitrogen deficiency.

The control countermeasure is to spray urea solution 2-3 times on the foliar surface. (2) The whole plant grows without obvious resistance to the loss of green and yellow, the loss of green and yellow between the leaf veins, the leaf edge is green, or there are residual green spots, no curl, and magnesium deficiency. The control countermeasure is foliar spraying of 1%-2% magnesium sulfate solution.

3) There is no obvious inhibition of plant growth, and the leaf edge loses green to necrosis, and sometimes there are green to necrotic spots on the leaves, which is potassium deficiency. The control countermeasure is to spray potassium dihydrogen phosphate solution 2-3 times. (4) There is no obvious resistance to plant growth, and the whole leaf has green to necrotic spots or stripes, which is zinc deficiency.

The control countermeasure is foliar spraying of zinc sulfate solution. The middle and upper young leaves are yellow first, and most of the missing elements are elements that are not easy to be reused in the plant, such as calcium, sulfur, iron, etc. (1) The growth point is dead, and the leaves lose green, shrink to necrosis; The root system is underdeveloped, and it rarely bears melons, which is calcium deficiency.

Control measuresFoliar spraying of calcium chloride solution 2 times a week. (2) The growth point does not die, the leaf color is light green, and the stem is small and lacks sulfur. The control countermeasure is foliar spraying of 1% potassium sulfate solution.

3) The growth point does not die, and the leaf color is yellow and white, which is iron deficiency. The control countermeasure is foliar spraying of ferric sulfate solution.

2. Downy mildew yellow leaves.

Downy mildew is a common and serious disease that occurs during the growth period of cucumbers. At the seedling stage, the leaves turn green and yellow, and finally die. At the adult stage, the leaves are diseased, and they begin to appear water-stained yellow round spots on the back of the leaves, especially in the morning, and gradually develop into yellow-brown polygonal lesions with yellow-green edges.

Under high temperature conditions, a gray-brown mold layer grows on the back of the lesions, and in severe cases, the lesions become patches, the whole leaves are yellow-brown, and the leaf margins are curled and wilted. The prevention and control countermeasure is to use 500 times of Ruixinhua, manganese-zinc 58% wettable powder or 75% chlorothalonil wettable powder, 50% lysohydrate wettable powder 600 times liquid for foliar spraying, once every 7 days, generally spraying 3-4 times.

3. Yellow leaves of wilt.

Fusarium wilt is commonly known as "dead seedling". In the early stage of the disease, some leaves wilt at noon, and can recover in the morning and evening, and do not recover after a few days. The leaf color gradually changes from yellow-green to yellow-brown, and gradually expands to the whole plant from bottom to top.

The main vine near the ground is brown and water-stained and rotten, thinning or longitudinally cracked, gradually drying up, and the whole plant is dead. Amber gelatinous flows out of the diseased part of the rhizome, and when the temperature is high, white or pink mold is produced on the surface, and when the stem or taproot is broken, the inside can be seen to turn brown. Prevention and control measures:

It is to irrigate the roots with 50% carbendazim 500 times of cherry wet powder, or 500 times of methyl tobuzine 50% wettable powder, each plant is not less than 250 m l, irrigated once in 5-6 days, and irrigated 2-3 times.

Question: How to prevent and treat cucumber leaf lesions? 2012-08-24 Cucumber downy mildew:

The disease can occur throughout the growth period of cucumbers, mainly affecting leaves. At the beginning of the disease, small water-soaked yellowish spots appear on the back of the leaves, and as the disease progresses, the lesions gradually expand, and polygonal yellow spots are formed due to the restriction of leaf veins. When the disease is severe, the small lesions merge into large lesions, and a gray-black mold layer grows on the back of the lesions under humid conditions.

The diseased leaves develop from the bottom up, and the whole leaves die in severe cases.

Cucumber powdery mildew: This disease mainly affects leaves. At the beginning of the disease, the dorsal and surface of the leaves produce white round powdery spots, which expand into patches, grow a layer of white powder, and gradually turn gray-white, and the leaves dry up and die after turning yellow, and do not fall off.

Bacterial horn spot in cucumber: This disease mainly affects the leaves, but sometimes it also affects the stems and melons. Cotyledons are damaged, initially water-stained, round or oval depressed spots, and later yellow-brown spots and dry up.

At the beginning of the leaf damage, the needle-sized water-stained spot is produced, and then it becomes light brown, and it is polygonal due to the restriction of the leaf vein, and when the humidity is high, white bacterial pus is produced on the spot on the back of the leaf, and it is a white transparent film after drying.

The cucumber trees are weak and the leaves are yellow, what's going on?

Teach you three tricks to keep the leaves of green plants from yellowing!

1. Reason: Cucumber is a relatively water-loving plant, but too much watering will also cause it to accumulate water, which is a taboo for breeding plants, which will lead to weakened root respiration and affect photosynthesis, resulting in problems such as cucumber and yellow leaves.

2. Treatment method: immediately stop daily watering, loosen the soil and ventilate, let the water dry, and it can get better after a period of time. If the problem is particularly severe, you can dig out a part of the soil without harming the roots, add some dry soil, and repeat it several times to speed up the drying of the soil.

1. Reason: When cucumber pests and diseases occur, most of the problems occur on the leaves of celery at the cucumber growth point, which will cause yellow-green mottled leaves, and then cause the leaves to turn yellow.

2. Treatment method: If pests and diseases have occurred, immediately cut off the leaves that have been infected with insects and spray pesticides on other leaves. Therefore, fungicides can be sprayed on the leaves in daily life, prevention is more important than **, so that pests and diseases can be kept away from it.

1. Reason: Cucumber is a plant that likes fertilizer very much, but too much fertilizer for a long time, especially too much fertilizer applied at one time, it is easy to burn the roots. It is unable to absorb nutrients, resulting in the occurrence of yellow leaves.

2. Treatment method: first irrigate the soil with large water and wash away the fertilizer saved in the area. After that, pause fertilization for a period of time and wait for it to recover.