What to do if the cucumber leaves are yellow, the stems are thin and the melon is topped

Nitrogen deficiency The plant is thin and weak, with slender and stiff branches, small leaves and small flowers. The leaf color gradually fades from the old leaves to the new leaves, and then appears reddish-purple, until it turns yellow and falls off, and in severe cases, the whole plant loses its green color.

Prevention and control methods Increase the application of well-rotted human feces, cake fertilizer, manure or ammonium sulfate, urea, ammonium nitrate and other fertilizers.

Phosphorus deficiency The leaves turn from dark green to copper, and the veins (especially petioles) are yellow with purple in color. Flower buds are difficult to form, and the flowers are small, few and pale in color, resulting in poor fruit development and even early wilting.

The control method is to increase the application of bone meal, fish meal, poultry fertilizer or superphosphate, ammonium phosphate, potassium phosphate (for phosphorus, potassium compound fertilizer), generally with about 0 10 aqueous solution as root top dressing.

Potassium deficiency Plants are short and have soft stems that are prone to lodging. The leaves are often shrivelled, and the old leaves appear black-brown spots along the leaf edges from the tip of the leaf, and the surrounding leaves turn yellow, while the middle and leaf pulse are still green.

Control methods Increase the application of plant ash, 1 2 potassium chloride aqueous solution (bulbs and tubers and flowers should not be used), 0 30 0 50 potassium nitrate aqueous solution as root top dressing, potassium phosphate and other inorganic fertilizers can also be used.

Calcium deficiency Young leaves are green and shrivelled, the leaf margins are curled with white streaks, the flowers are blocked, and the new leaves are difficult or diseasefully twisted.

Prevention and control methods Half a month before sowing or potting, apply an appropriate amount of calcium chloride in the soil, which can play a role in increasing calcium and disinfection (acidic flowers should not be used), and calcium nitrate can also be used as top dressing.

Magnesium deficiency Plants do not grow vigorously. The old leaves gradually lose green and turn white from bottom to top from the leaf margin to **, and various spots appear on the leaf veins, and finally the whole leaf turns yellow.

Prevention and control method spray 3-4 times continuously with 0 20 0 40 magnesium sulfate aqueous solution, with an interval of 7 10 days each time. Severely magnesium deficient soils are treated with 5 10 kg of magnesium sulfate per mu, which is mixed with basal fertilizer in autumn or winter and applied to the soil.

Sulfur deficiency Young leaves begin to yellowish from the veins, and finally until the whole leaves turn yellow, and the root system is not developed normally.

Iron deficiency yellows from young to old leaves.

Sulfur deficiency and iron deficiency prevention and control methods can be sprayed with 0 30 ferrous sulfate aqueous solution, 3 times in a row, with an interval of 1 week each time, and the fog point should be fine and uniform when spraying. At the same time, 0 20 urea iron solution can be used for extra-root top dressing.

This will help you solve various problems later on.

Hello, I'm glad you about "What should I do if the cucumber roots are thin and don't grow and the leaves are yellow?" ".

This situation is often caused by a lack of nutrients, so you can try to increase fertilization, such as supplementing with an appropriate amount of nitrogen, phosphorus and potassium fertilizers. In addition, it is also possible to choose the right soil, keep the environment warm, increase humidity and temperature, and enrich the soil organisms to ensure that air, water, and nutrients work in harmony in cucumbers.

In addition, you can also try to apply an appropriate amount of pest and disease prevention agents, which can not only slow down the damage of diseases, but also prevent the occurrence of diseases and enhance the disease resistance of cucumbers.

Finally, we must pay attention to keeping the soil moist to avoid the appearance of diseases, watering cucumbers every 3-4 days, the amount of water can be increased or decreased according to the different seasons, nutrients are also equally important, the quality of the soil and nutrients can be increased before farming, and appropriate plant protection technology can effectively reduce the incidence of diseases.

Wishing your cucumbers good growth and happy holidays!

There are several reasons for the yellowing of cucumber leaves:One is to water it too much, the root system will rot due to lack of oxygen in the soil, and yellow leaves will appear.

The second is to apply too much fertilizer to it, and if there is excess nutrition, it will also cause the leaves to turn yellow.

The third is to be directly exposed to the sun by the intensity of summer.

Fourth, there is a lack of trace elements.

Hello! For example, cucumber rod spore leaf spot (also known as cucumber brown spot disease). This disease has occurred more often in Liaoning in recent years. In general, early prevention should be taken. The pesticides used are imimidide and difenoconazole (Shigao).

In addition, if you plant cucumbers again, there are some measures. When grafting cucumbers and pumpkins with seed sterilization, it is necessary to pay attention to the pumpkin seeds that do not carry bacteria. Soak cucumber seeds and grafted black-seeded pumpkin seeds in warm water at 55 for 30 minutes.

Agricultural measures: Diseased fields should be rotated with non-melon crops for more than 2 years. Completely remove the diseased and residual plants in the field and then turn the soil deeply to reduce the source of the initial invasion in the field.

Apply sufficient basal fertilizer, top dressing in a timely manner, avoid partial application of nitrogen fertilizer, increase phosphorus and potassium fertilizer, and apply boron fertilizer appropriately. To prevent premature senescence of cucumber plants, pay attention to wind and dampness after watering, and remove diseased leaves at the beginning of the disease. Pharmaceutical prevention and control:

At the beginning of the disease, use 75% chlorothalonil wettable powder 500 times, or 70% mancozeb wettable powder 500 times, or 50% foomet double wettable powder plus 65% zeb wettable powder (1:1) 500 times, or 75% chlorothalonil wettable powder plus 70% carbendazim wettable powder (1:1) 500 times, or 75% chlorothalonil wettable powder plus 50% sucrin wettable powder (1:

1) 1 000 times liquid and other chemical sprays, once every 7 days, continuous prevention and control 2 3 times.

1.If the old leaves are yellow, if you find that the middle and lower leaves of the cucumber lose green and yellow, and the color of the upper young leaves is normal, this situation often occurs in the middle of growth, the main reason is that the vegetative growth is fast, and the nitrogen fertilizer in the soil is insufficient.

2.Yellowing of new leavesIf the middle and lower leaves of the cucumber are normal, but the newly grown leaves at the top are yellow, this symptom is generally a deficiency symptom, and iron deficiency is usually the most likely. The cause of soil iron deficiency may be excessive soil moisture, especially after heavy rain, waterlogging in the ground, lack of oxygen in the soil roots, and weakened fertilizer absorption ability.

We need to remove water from the soil in a timely manner.

3.Yellow spots on the whole leaf If there are yellow spots on the new and old leaves of cucumbers, it is most likely that a disease has occurred, the most common being downy mildew of cucumbers. Cucumber downy mildew is a frequent disease of cucumbers, once this yellow spot is found, it should be prevented and controlled in time, chlorothalonil, mancozeb can be used in the early stage, and downy mildew can be used in the middle and late stages.

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The top leaves of cucumbers are yellow, the leaves are curled, and the vine buds are hard, what is going on?

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Hello, it is a pleasure to serve you, cucumbers generally have insect infestations, water and nutrient deficiencies can also make the tips of cucumber leaves curl. Cucumber leaf curling is related to mild pesticide damage (crop leaf curling occurs when the concentration of pesticides, fungicides or liquid potato fertilizers is high).

The cucumber sedan chair shouted that the leaf curl was closed, and the pest pests such as aphids and trembling were related. If cucumbers have aphids, red spiders, mites and other pests, they will suck the leaf juice at the top of the leaf, causing the leaf to roll over.

Cucumber leaf curling is associated with the decline of soil moisture. Due to the long period of sunny weather and no rain, the soil moisture decreases, and when the strong Taiqing Empty Talk is exposed to the sun, the water evaporation is large, and the leaves lose water, and the top of the leaves will curl up.

Spray the foliar fertilizer of iron supplementation, and then flush the organic nitrogen fertilizer of the faucet, remove the melon, bent melon, big-headed melon, etc. in time to avoid nutrient waste, potassium fertilizer should be used less or not at all, and foliar fertilizer should be sprayed frequently.

It's time to water, plus flush fertilization....

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 most of the missing elements are 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 of the older leaves lacks green, which is nitrogen deficiency. The control countermeasure is to spray urea solution 2-3 times on the foliar surface.

2) The whole plant growth has no 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, 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 streaks, 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 the elements that are not reused in the body, such as calcium, sulfur, iron, etc.

Solution: 1) The growth point is dead, and the leaves lack green and 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 control countermeasure is to use 500 times of Ruifuxin, manganese zinc 58% WP or 75% chlorothalonil WP, 50% lysophilam WP600 times solution for foliar spraying, once every 7 days, generally spraying 3-4 times.

3. Yellow leaves of blight:

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 WP500 times, or methyl tobujin 50% WP500 times, each plant is not less than 250ml, irrigated once in 5-6 days, and irrigated 2-3 times.