What is the reason for the yellowing of rape leaves, and the reason for the whitening of rape leaves

1.Natural consumption.

Reason: Rape flowers consume some of their own stored nutrients during the winter, and then they will show local yellowing of leaves.

Measures: The yellowing of the leaves caused by natural consumption is generally not too large, don't worry, just continue the normal maintenance. If the yellowing area is relatively large, this cause can be ruled out and other factors can be considered.

2.Disease problems.

Causes: Common diseases of rape flowers include downy mildew, white rust, etc., which can easily cause a large area of leaves to turn yellow. Downy mildew can cause some polygonal yellow spots on the leaves of rape flowers, and in severe cases, the whole leaf will turn yellow.

White rust causes white raised blisters on the back of the leaves, and in severe cases, yellowing of the leaves.

Measures: At the beginning of the disease, you can spray the whole plant with 50% methyl copper wettable powder 600 times or 58% manganese zinc wettable powder 800 times to the whole plant**, once every seven to ten days, spray two or three times in a row to get better.

3.Lack of phosphorus and potassium fertilizers.

Reason: Rape flowers have a large area of yellow leaves, which may be due to the lack of phosphorus and potassium fertilizers in the soil. This condition causes the edges of the leaves to appear burnt brown and then slowly turn yellow.

Measures: Some phosphorus and potassium fertilizers can be applied in an appropriate amount to supplement the nutrients in the soil. However, if it is a potted rape flower, you can pour a little fermented rice washing water into it, and the problem of yellow leaves can be alleviated.

4.Lack of trace elements.

Cause: When there is a large area of yellow leaves, if the above causes are ruled out, then it may be due to a lack of trace elements. The yellowing of the old leaves at the base of the plant is usually due to a lack of magnesium, and the yellowing of the new leaves may be due to the lack of a variety of trace elements.

Measures: You can apply some micro-tonic root force calcium + energy + punch magnesium at the bottom of the plant, and at the same time spray some micro-tonic fruit power + Bili to the foliar surface to supplement the calcium and phosphorus elements required for plant growth and promote the recovery and growth of rape flowers.

The yellowing of canola leaves can be caused by cold weather, and in winter, the temperature is very low, but the plant needs the right temperature to grow. Yellowing of canola oil is normal and is usually caused by severe frost or extreme cold.

Abstract Hello, there are two cases of rape leaves turning white. The first is caused by the common white rust of rapeseed, which will harm the leaves, stems, flowers and horns, etc., and the symptoms on the leaves are mainly small pale green spots, which turn yellow after turning yellow, and the leaves will slowly wither and fall off; The second is caused by the freezing of rapeseed at the bottom of the temperature.

Causes of whitish rape leaves.

Hello, there are two cases of rape leaves turning white. The first is caused by the common white rust of rapeseed, which will harm the leaves, stems, flowers and horns, etc., and the symptoms on the leaves are mainly small pale green spots, which turn yellow after turning yellow, and the leaves will slowly wither and fall off; The second is caused by the freezing of rapeseed at the bottom of the temperature.

Hello, there are two cases of rape leaves turning white. The first is caused by the common white rust of rapeseed, which will harm the leaves, stems, flowers and horns, etc., and the symptoms on the leaves are mainly small pale green spots, which turn yellow after turning yellow, and the leaves will slowly wither and fall off; The second is caused by the freezing of rapeseed at the bottom of the temperature.

There are many reasons for the yellowing of rape leaves, and there may be a lack of water; There may be a lack of fertilizer; It may be caused by low temperatures.

The main diseases that occur when the leaves of rape are yellowing are downy mildew and white rust. The manifestation of downy mildew is the appearance of polygonal yellow lesions on the front of the leaves, which are yellow and scorched in severe cases, and white mold layer on the back of the leaves when wet; White rust is a white raised blister on the back of the leaf, which breaks when it matures, emitting a white powder, and in severe cases, the whole patch is yellow.

Rapeseed fertilization technology <>

1.Pre-fertilization.

Cultivating strong seedlings before winter is the key to high yield of rapeseed, rapeseed fertilization should adopt the strategy of promoting stability before and after, generally, two-thirds of all nitrogen fertilizer and all phosphorus and potassium fertilizer and boron fertilizer base application, or seedling application, the rest of the nitrogen fertilizer is applied as rapeseed moss fertilizer, in the seedling period of rape in November generally more rainy days, less light, seedling inconsistency, etc. In order to obtain strong seedlings, rape before the five-leaf stage was topped with water-soluble fertilizer for vines per mu.

2.Fertilize during flowering.

The flowering period of rape is longer than the flowering period of general plants, flowering and poding period, the flowering period can be as long as about 30 days, the consumption and transformation of nutrients in this period is the largest, so the water and fertilizer should be timely in the flowering period of the sprout, and the topdressing time should be appropriately advanced to the bud period. Foliar fertilizer is a simple and effective way to top dressing outside the roots, in the flowering and podding stage, with urea aqueous solution, add potassium dihydrogen phosphate, add boric acid solution foliar spray 1-2 times, avoid the morning pollination period.

3.Fertilization at the pod stage.

The sensitivity to phosphorus fertilizer in the middle and late stages of rape is very high, and the lack of phosphorus in the later stage has a great impact on the yield and fertility demand of rapeseed, and the method of foliar spraying is generally used in the later stage, and in the pod maturity period, foliar spraying of 2 3% superphosphate aqueous solution or potassium dihydrogen phosphate aqueous solution is used to improve the quality of rapeseed, which has a very good positive effect.

There are probably four reasons for the yellow leaves of rape flowers. If it is due to natural consumption in winter, don't worry, just continue normal maintenance; If it is because of the disease, it is necessary to spray a specific drug**; If it is because of the lack of phosphorus and potassium fertilizer, it is necessary to apply some phosphorus and potassium fertilizer in an appropriate amount to supplement the nutrients in the soil. If it is due to a lack of trace elements, it is necessary to supplement the trace elements for different parts of the plant.

Flower Encyclopedia.

The yellowing of the leaf edges and the green veins of the mesophyll may be due to the lack of potassium in the green disease, which will affect the transfer of nutrients produced by photosynthesis of the leaves to rapeseed. Foliar sprays of potassium dihydrogen phosphate.

The causes of yellowing of vegetable leaves include root problems, nutritional problems, and insect pests, which can be controlled according to the problems. The details are as follows:

1. Root problems

One of the most common reasons is that plants rely on their roots to grow and absorb nutrients, and if there is a problem with the roots, the natural plants will not grow. The mild manifestation is yellowing, and when it is more severe, it may begin to slowly wither and die.

Do not use a lot of fertilizer, pay attention to a cold protection work, for example, the root system is not very developed, or if the roots are very shallow, it is difficult to overwinter.

2. Unbalanced nutrition

For crops, it is necessary to pay attention to sufficient ** to achieve a state of equilibrium between supply and demand. However, many people are prone to misunderstandings in the use of fertilizers, such as using a lot of those large elements, thinking that the effect is more obvious, and ignoring some small elements will easily cause yellowing.

Pay attention to the nutrition of plants, especially the ** of small elements, which will reduce the yellowing.

3. Caused by disease

There are also a lot of diseases that plants can be infected with, sometimes it seems that they are okay on the surface, but in fact, those diseases are all in the plants, harming the root system of plants, and slowly causing the plants to turn yellow.

Before planting, be sure to disinfect the land to a certain extent, and pay more attention to it in normal times. If there are insects, pay attention to the use of pesticides, this should be proportioned according to the regulations, and the ratio is too strong to make the crops yellow.

Disease symptoms of yellow leaf disease of cabbage vegetables

Chinese cabbage, small cabbage, and yellow leaf diseases such as cabbage and yellow sprouts occur from north to south. Onset is seen at the seedling stage. After the seedlings are set or planted, the growth is slow, half of the leaves fade green, causing half or the whole plant to wilt, as if lacking water, pulling out diseased plants, few fibrous roots, cutting the taproot, vascular bundles.

Browning. After the rosette to the early stage of the center, the leaves begin to yellow, and enter the middle stage of the center, the old leaves fade and turn yellow between the veins, and the veins around the veins remain dark green, and the posterior leaf margins lose water and shrink and curl inward, causing the plants to shrank or die.

The above information refers to Encyclopedia - Yellow Leaf Disease of Cabbage Vegetables.

Summary. Frost damage, the drop in temperature in the past few days caused frostbite on some rape leaves.

Insufficient water and fertilizer, sudden changes in weather, and frost damage will be caused.

The whitening of rapeseed leaves should consider the harm of white spot disease.

The whitish leaves of rapeseed should be caused by insufficient fertilizer and water or low temperature frost damage.

When the temperature is low, it is necessary to control water and fertilizer, prevent pests and diseases, and do a good job of weeding.

Frost damage, the temperature dropped a few days ago, and the staring was dismantled into some rape leaves with frostbite. Insufficient water and fertilizer, sudden changes in weather, and frost damage will be caused. When rape is old, the leaves are white, and the harm of white spot disease should be considered.

The whitish leaves of rapeseed should be caused by insufficient fertilizer and water or low temperature frost damage. When the temperature is low, it is necessary to control water and fertilizer, prevent pests and diseases, and do a good job of weeding.

Summary. The reasons for the appearance of yellow leaves of rape are as follows: 1. Nitrogen deficiency of yellow leaves: If the nitrogen fertilizer is insufficient at the seedling stage of rapeseed, the plant is dwarf, the leaves are small, the new leaves are born slowly, the leaf color gradually turns yellow-green or yellow, and sometimes the leaf edges of the lower stem are yellow, and gradually expand to the leaf veins.

Control measures: 15 20 kg of ammonium bicarbonate per mu can be applied, and foliar sprays can also be carried out with 1% 2% urea solution. 2. Sulfur deficiency yellow leaves:

Sulfur-deficient yellow leaves are different from nitrogen-deficient yellow leaves, in that sulfur deficiency starts to turn yellow from young leaves, while nitrogen deficiency develops from old leaves to new leaves. Control measures: 10 kg of gypsum powder per mu can be applied to sulfur-deficient rape in combination with cultivation to promote the change of leaf color.

Excuse me, what is the cause of yellowing of rape leaves and how to prevent it?

What is the reason why the leaves turn yellow and fall off shortly after the rape is planted? How to govern it?

Don't copy and paste! Let's get a practical answer.

The reasons for the appearance of yellow leaves of rape are as follows: 1. Nitrogen deficiency of yellow leaves: If the nitrogen fertilizer is insufficient at the seedling stage of rapeseed, the plant is short, the leaves are small, the new leaves are born slowly, and the leaf color gradually turns yellow-green or yellow. Prevention and control measures:

15 20 kg of ammonium bicarbonate per mu can be added, and foliar spraying can also be carried out with 1% 2% urea solution. 2. Sulfur-deficient yellow leaves: sulfur-deficient yellow leaves are different from nitrogen-deficient yellow leaves, sulfur deficiency is from young leaves to yellowing, while nitrogen deficiency is the development of old leaves to new leaves.

Control measures: 10 kg of gypsum powder per mu can be applied to sulfur-deficient rape in combination with cultivation to promote the change of leaf color.

The main thing to look at is the specific ** first yellow.

It is also known that there is a kind of acid damage to the yellow leaves, which is manifested as the new leaves are only yellow and do not wither, and then fall off. Prevention and control measures: 50 kg of lime and 50 kg of grass ash can be applied per mu to neutralize soil acidity and eliminate acid damage.

The edges of the leaves are yellow at first, and then fall off.

After the yellow, it withered.

A little. It can tell whether it is a new leaf or an old leaf.

Old. There is a high probability that it is a nitrogen deficiency.

Oh. It is not the new leaves that exclude the second kind.

Apply some nitrogen fertilizer, add 15 20 kg of ammonium bicarbonate per mu, and can also use 1% 2% urea solution for foliar spraying.

Well. Just transplant, be careful not to overdose.

Excuse me, what is the cause of yellowing of rape leaves and how to prevent it?

Hello dear, there are these reasons: 1. Insufficient nitrogen fertilizer at the seedling stage of nitrogen deficiency yellow leaves will cause the leaves of rape to become smaller, the new leaves to turn yellow, and the lower leaves of the stem will turn yellow, and will expand to the leaf veins, ammonium bicarbonate can be applied for remedy, and foliar sprays can be carried out with 1%-2% urea solution. 2. Sulfur deficiency in yellow leaves is the yellowing of young leaves, which is essentially different from the yellowing caused by nitrogen deficiency, and gypsum powder can be appropriately applied to promote the transformation of leaf color. 3. After the occurrence of acid damage to yellow leaves, the new leaves are only yellow and not withered, and then fall off.

Quicklime and plant ash can be applied for remediation, neutralizing soil acidity and eliminating acid damage. 4. Boron deficiency in yellow leaves will cause rape leaves to become smaller and uneven. Timely topdressing of boron fertilizer is required for recovery.