Cucumber, what to do if the melon is yellow, what is the reason for the yellowing of cucumber and me

There are many conditions that can cause yellowing of cucumber leaf edges, some occur in the middle and lower leaves, some occur in the new leaves, and some occur in the middle and upper young leaves. But whatever the cause, it's a physiological disease.

The first is due to a deficiency or excess of potassium. Yellowing of leaf edges caused by potassium deficiency or potassium excess, mostly occurs on the middle and lower leaves. Potassium deficiency is rare, and yellow fringes caused by excessive potassium are the most common.

Because cucumber is a fertilizer-loving crop, the amount of fertilizer is very large, so there is generally no yellow edge caused by potassium deficiency. Therefore, most of the causes of yellow fringes are caused by excessive potassium.

Second, the high concentration of soil solution and salinization are also the causes of yellow edges. This situation often leads to the yellowing of cucumbers from the bottom up. The data show that cucumber absorbs nitrate nitrogen quickly, and the absorption of ammonium nitrogen and amide nitrogen is not as good as nitrate nitrogen, while vegetable farmers use mostly ammonium nitrogen, and a large amount of ammonium nitrogen cannot be converted into nitrate nitrogen by soil microorganisms after being applied to the soil, and the accumulation in the soil directly leads to the high concentration of soil solution.

The high content of nitrogen and potassium ions in the soil leads to soil salinization, which inhibits the movement of various elements in the soil, and the high salt concentration will cause the root cells to undergo plasma wall separation, which greatly inhibits the absorption of other trace elements, such as boron, iron, etc., and is also easy to cause leaf yellowing.

Third, calcium deficiency leads to yellowing of leaf margins. The yellow edge caused by calcium deficiency mostly occurs in the young part of the plant, and generally the yellow edge of the young leaf appears more uniformly, and in severe cases, it will expand inward. Due to soil drought or overwatering, cucumber roots are injured, affecting the absorption of calcium by the roots.

Due to the large application of chemical fertilizers, the concentration of soil solution increases, which inhibits the movement of calcium, and the content of nitrogen and potassium in the soil is too high, which plays an antagonistic role in calcium and reduces calcium absorption.

Fourth, drug damage and gas damage can lead to yellow edges. In this case, the middle and lower leaves are mostly damaged, and the leaf margins turn yellow at the beginning and scorch at the later stage. Due to the frequent occurrence of diseases in winter, in order to prevent diseases, many vegetable farmers basically spray pesticides every few days to prevent them.

If a disease occurs, the number of spraying increases significantly, and some take fumigation measures to prevent the humidity in the shed from increasing. If applied for a long time or at a high rate, it will cause the edges of the leaves to turn yellow. A lot of harmful gases will be produced in the process of top dressing and fumigation, and if it is not ventilated in time, it will cause the leaves to be Phnom Penh.

Although it is not a big problem to say that cucumber leaves are inlaid with gold edges, from the perspective of the reasons for this situation, there is a great hidden danger to the growth of cucumbers. Therefore, after finding that the cucumber has yellow edges, it is necessary to analyze the reasons in time and strengthen prevention and control to avoid more serious problems.

Low temperature, less light, large temperature difference caused by low temperature obstacles, must be timely foliar spraying natural brassinin plus Gaomei humic acid active liquid fertilizer plus potassium dihydrogen phosphate plus triacosanol, or sodium nitrate phenol plus amino acid active liquid fertilizer plus Xingpeng phosphorus and potassium No. 1 plus Gaolida light fertilizer for remedy, once every 7 10 days, 2 3 times in a row, in order to speed up the recovery of normal growth.

Poor root development of cucumber is the main cause of yellowing of melon strips, and poor root development will affect the growth and development of the whole plant, so that cucumbers can not get sufficient nutrition, and then cause yellowing of melon strips. Prevention and control change planting methods: Many vegetable farmers often dry first and then water when planting.

The disadvantage of this is that the surface layer is full of water and fertilizer, and the root system develops horizontally in the superficial layer, but it is not conducive to the deep expansion of the root system. If watered thoroughly before planting, it can induce the root system to develop to depth, and at the same time, watering first can also reduce the ground temperature, which is more conducive to root growth and slow down seedlings. Protects leaves and promotes rooting

Most of the nutrients required by the root system are provided by the middle and lower leaves, so the lower leaves should not be removed too early, and leaf diseases should be strictly controlled. Reasonable fertilization, root maintenance and root protection: After the appropriate amount of basal fertilizer is applied in the shallow layer, the biological fertilizer is deeply applied in the planting site, which can improve the soil, prevent diseases, promote the growth of new roots and promote the development of the root system to the depth to form a thick root system.

After the vegetables enter the fruiting period, the vegetative growth and reproductive growth are synchronized, and the fertilizer is applied to ensure that the root system is not harmed.

Reason 1: Changes in the external environment, sudden changes in temperature, humidity and light will cause cucumber leaves to turn yellow.

Solution: Cucumber is a typical thermophilic plant, with a fertility temperature of 10 32. The suitable temperature is higher during the day, about 25 32, and the lower temperature at night, about 15 18.

The appropriate temperature for photosynthesis is 25 32. It is necessary to adjust the temperature of the greenhouse in a timely manner, such as ventilating.

Reason 2: Excessive watering, too much water leads to yellowing of cucumber leaves (water yellow): The leaves of the plant are generally yellow, especially the top leaves are small, the growth is slow, and wilting occurs in severe cases.

Solution: The appropriate soil relative humidity is 85%-90%, cucumber has a strong adaptability to air humidity, and the relative humidity of the air at night can reach 90%-100%, but the humidity is too high and prone to disease, so it is not possible to water cucumber seedlings many times, so as to prevent the root system from growing normally due to excessive water and lack of oxygen.

Reason 3: Too much fertilization, although cucumber planting has a lot of nutrient demand, but it is not possible to arbitrarily increase the amount of fertilizer, too much nutrients will cause excess nutrients in cucumber plants, causing yellow leaves.

SolutionCucumber fertilization should be carried out according to different growth stages, in the middle and late stages of balanced and high potassium fertilizer-based, the seedling stage is generally topdressing once or twice, and the middle and late stages can be applied once at an interval of 10-15 days to meet the nutrient needs, the fast-acting water-soluble fertilizer is faster than the traditional fertilizer absorption, and the yield is obvious, of course, the bottom fertilizer before planting cucumbers is essential.

Reason 4 cucumber deficiency, cucumber demand for trace elements is also a lot, such as magnesium, boron, iron, zinc, calcium, etc., if a large shortage of these elements will reduce the quality of cucumber plants, fruits, etc., for this in the middle and late topdressing process should also take into account the supplement of trace elements.

Solution: Spray cucumber special foliar fertilizer to comprehensively supplement nutrients, improve the quality of cucumber plants and cucumbers, and enhance the resistance to common diseases.

Cause 5 pests and diseases, the symptoms of which mostly occur on the leaves of the cucumber growth point, resulting in yellow-green mottled flowers and leaves.

Solution: The occurrence of cucumber diseases and insect pests will turn the leaves yellow together, and fungicides can be added to it at the same time as daily spraying of foliar fertilizer, so as to kill two birds with one stone and treat the disease at the same time.

Generally speaking, planting cucumbers in a suitable environment, scientific and reasonable bottom fertilizer plus top dressing is an important method to promote cucumber straightening, elongation, top flowers with thorns, standardized planting and scientific management is the most efficient way to increase the yield of greenhouse vegetable crops.

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

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. It is the growth of the whole plant that is inhibited, and the whole leaf of the older leaves lacks green first, which is nitrogen deficiency. The control countermeasure is to apply 1% urea solution 3 times.

The second is that there is no obvious inhibition of the growth of the whole plant, the leaf veins lose green and turn yellow, the leaf edge is green, or there are green spots remaining, not curled, and it is magnesium deficiency.

Causes of yellowing of cucumber seedlings:

1.Moisture management.

The yellowing of the leaves of cucumber seedlings may be related to the amount of watering. If you water less, it will dry out the soil, causing the leaves of cucumber seedlings to turn yellow due to lack of water. If you water too much, it will cause water on the ground to affect the respiration of the root system, which will lead to a lack of oxygen in the root system and yellowing of the leaves.

Cucumber seedlings should be watered about every 3-5 days, as long as the soil is kept moist, remember not to form stagnant water.

2.Fertilization management.

When cucumber is used in the seedling stage, the organic fertilizer or fertilizer amount that is not fully decomposed will cause the root burning of cucumber seedlings, resulting in damage to the root system of cucumber seedlings, so the leaves are yellow. At this time, it is necessary to water and dilute it in time.

3.Temperature management.

When the ambient temperature of cucumber seedlings is too low, it will affect the root growth of cucumber seedlings. It will also cause the leaves of cucumber seedlings to turn yellow, and the temperature of the seedbed needs to be increased at this time. We can choose to cover the mulch film this method to solve the problem of the ambient temperature is too low.

Generally, the temperature at which cucumber seedlings grow normally is between 15-25 degrees Celsius.

4.Soil selection.

If the soil for planting cucumber seedlings is too compacted or too acidic and alkaline, this will affect the growth of the root system, resulting in the yellowing of the leaves.

Causes of yellowing of cucumber seedlings:

1. Temperature change.

Cucumber is a typical thermophilic plant, the growth temperature is 10-32 degrees, when the temperature exceeds this range, the seedlings will be unable to adapt to the changes in the environment and appear yellowing, at this time to do a good job of temperature control.

2. Overwatering.

Cucumber has strong adaptability to air humidity, but if the soil moisture is too large, it will cause the root system of the seedlings to rot, resulting in yellowing of the leaves.

3. Excessive fertilization.

Cucumber seedlings can not be arbitrarily increased fertilizer during the growth period, otherwise it will cause cucumber seedlings to overnutrient and yellow, in the seedling stage of the plant generally only need to apply compound fertilizer once, and the base fertilizer in the soil is enough to support the growth of seedlings.

4. Lack of nutrients.

Cucumber seedlings have a greater demand for trace elements such as magnesium, boron, iron, zinc, calcium, etc., if the seedlings lack these elements during the growth period, it will cause insufficient nutrition and yellowing.

What is the reason for the yellowing of cucumber seedlings.

1. Temperature change: The temperature exceeds the range of 10-32 degrees, and the cucumber seedlings turn yellow because they cannot adapt to the changes in the environment.

2. Excessive watering: excessive soil moisture causes the root rot of cucumber seedlings.

3. Excessive fertilization: increase fertilizer arbitrarily during the growth period of cucumbers.

Cucumber seedlings turn yellow. If you water too much, the roots will be watered, so you can use some rooting agent to get used to it and it will slowly turn green, and it will be fine.

The main reasons: 1. The root system is injured, and after the cucumber root system is injured, it affects the growth and development of the whole plant, often causing the melon to turn yellow, which is called Huagua;

2. Under the influence of drugs, vegetable farmers sprayed pesticides with strong inhibitory effect under inopportune circumstances, causing yellowing of melon strips;

3. Nitrogen and potassium fertilizer are insufficient, nitrogen is a component of many important organic compounds in plants, and potassium is a quality element of plants;

Solution: 1. Leave melons reasonably, generally leave a melon in three leaves, according to the growth of the plant, leave three melons on a plant;

2. Reasonable defoliation to ensure that there are 12 to 15 leaves on the plant, which can meet the needs of organic nutrients such as fruits, stems, and roots;

3. Supplement all nutrients in a balanced manner, apply water-soluble fertilizers with high utilization rate and full nutrients, avoid nutrient imbalance and waste, and meet the needs of large, medium and trace elements in cucumber growth.