Magnolia leaves only have leaf veins and no mesophyll, what pest harms?

Magnolia is a disease-resistant tree species, and the main diseases are anthracnose, yellowing and leaf burn. You and I look at it as the second type.

Symptoms and rules of yellowing disease: firstly, the leaves fade green, the chlorophyll gradually decreases, the leaves are yellow or light yellow, the leaf veins are still green, the whole leaf turns yellow after the disease expands, and then gradually turns white, the plant growth gradually declines, and finally dies.

Prevention and control methods: yellowing is a physiological disease, mainly caused by excessive soil viscosity, excessive pH value, and insufficient iron. Ferrous sulfate solution can be used to irrigate the roots, ferrous sulfate solution can also be used for leaf spraying, and more farm fertilizer should be applied.

It should be soft rot and can be sprayed**.

1. Prepare the seedbed.

About 4 days before the broccoli seeds are planted, the seedbed should be prepared. Do a good job of disinfection of the seedbed, sprinkle the seedbed with methyl tobuzin and other agents, and then apply sufficient farmhouse fertilizer, refine the soil and rake it, and fully mix the fertilizer with the soil. If it is a newly developed planting area, it is best to sprinkle some nutrient soil to improve the fertility of the soil.

And also ensure that there is sufficient sunlight and suitable temperature. The most important thing is to have a clean enough water source to provide enough water for the broccoli during the planting process.

2. Sow seeds and raise seedlings.

Before sowing, the seeds of broccoli should be disinfected and germinated, and the seeds should be dressed with Fumei double agents to eliminate germs. Then soak the seeds in warm water for about 3 hours, and the water level of the soak should ensure that the left and right seeds are submerged. It is then placed at about 22 degrees Celsius for germination, and when most of the seeds are exposed, they can be sown.

When sowing, we should pay attention to controlling the planting density, cover the soil after sowing to see the seeds is appropriate, and finally cover the soil with film to improve the thermal insulation ability of the soil and promote the germination of seeds.

3. Transplanting and colonization.

Before the seedlings emerge, the temperature should be controlled at about 23 degrees during the day, and the temperature should not be lower than 13 degrees at night. Then, when the broccoli seedlings are unearthed, the seedlings can be managed well, and when the seedlings grow about 5 true leaves, the planting work can be carried out within a month. First of all, it is necessary to prepare the field, remove the branches and weeds left in the field in time, and carry out land preparation and fertilization.

Before transplanting, it is necessary to water enough to prevent root injury and control the planting density. After planting, the surrounding soil is compacted and the rooting water is watered again.

4. Water and fertilizer management.

Within 2-3 weeks after planting, broccoli should be topdressed, and the fertilizer is mainly urea. It is necessary to pay attention to the control of the dosage, not too much or too little, too little can not meet the growth nutrition, too much is easy to cause broccoli fertilizer. The nutritional demand of broccoli is very large, and we must also control the nutrient ratio, among which the nitrogen fertilizer demand is the largest, mainly phosphorus and potassium, and we should also pay attention to the supplementation of boron and magnesium and other trace elements that can be sprayed with boron fertilizer.

Broccoli also requires a lot of water, especially during important periods such as broccoli balling, so keep the soil moist at all times. However, the water should not be too much, if there is too much water in the seedling stage, it is easy to cause broccoli diseases and pests.

1. Broccoli disease - soft rot.

1. Symptoms. It is a bacterial disease, and broccoli is prone to occur when it encounters more rain in the later stage of growth. The lesions are water-stained, gradually softening and decaying, producing a foul smell; Germs invade from wounds on roots, stems, and leaves.

2. Prevention and control methods. Avoid co-cropping with cruciferous vegetables, especially cabbage and cabbage. Strengthen field management and cultivate strong seedlings.

Avoid injuries and pay attention to drainage after rain. At the beginning of the disease, spray streptomycin sulfate, or 72% agricultural streptomycin wettable powder 3000 4000 times, or new phytomycin 4000 times.

2. Broccoli disease - downy mildew.

1. Symptoms. It is a fungal disease, which is more obvious in the development process of flower bulbs, the old leaves first develop the disease, and then spread to the young leaves, and the lack of green and the yellowing of the leaves appear in the early stage of the disease. When dry, the leaves dry out, and when wet, mold appears on the back of the leaves.

2. Prevention and control methods. Choose varieties that are highly resistant to disease. Avoid continuous cropping, the soil should be turned deep and whitened, and an appropriate amount of lime should be applied to improve. At the beginning of the disease, spray with 600 800 times of 70% mancozeb wettable powder, or 400 600 times of methamphene.

Note: Discontinue the use of pesticides 10-15 days before harvesting.

3. Broccoli insect pest - diamondback moth.

1. Symptoms. The first instar larvae can only feed on the mesophyll, leaving a transparent epidermis, and the 3 to 4 instar larvae can eat the leaves into holes, and in severe cases, the whole leaves are eaten into a net.

2. Prevention and control methods. At the beginning of the disease, black light is used to trap and kill adult insects. It can also be sprayed with 500 1000 times of Bacillus thuringiensis preparation, or 1000 2000 times of 50% phosphine emulsifiable concentrate.

Note: Stop using pesticides 10 days before harvesting.

Fourth, broccoli insect pest - vegetable aphid.

1. Symptoms. The damaged plants are seriously dehydrated, shrinking, yellowing, twisted and deformed, and the damage of vegetable aphid can also cause soot disease and spread virus diseases.

2. Prevention and control methods. Set up yellow plates to trap aphids in the broccoli field, and 8 yellow plates per mu. Hang silver-gray membrane strips to avoid aphids, the membrane width is 12 23 cm, and the height is less than 1 meter.

At the beginning of the disease, spray with 40% dimethoate 1000 times liquid, or 80% dichlorvos emulsifiable concentrate 1000 2000 times liquid.

Note: Discontinue the use of pesticides 15 days before harvesting.

5. Broccoli insect pest - cabbage insect.

1. Symptoms. The larvae eat the mesophyll, leaving only a layer of transparent epidermis, and only leaf veins are left, which is prone to soft rot when harming the flower bulbs, and insect feces will also pollute the flower bulbs and reduce the value of the commodity.

2. Prevention and control methods. At the beginning of the disease, spray with BT emulsion, or 500 800 times of green worm 6 solution, or 1000 times of 50% phoxanthion emulsifiable concentrate, or 3000 4000 times of 20% fenvalerate emulsifiable concentrate. If it rains after spraying, it should be sprayed.

Downy mildew downy mildew is a fungal disease that occurs mainly when broccoli has flower bulbs. In the early stage of downy mildew, it is mainly manifested on the old leaves, and then slowly spreads to the center, and the leaf surface will turn yellow and finally dry up. If there is dew or excessive humidity, mold will appear on the back of the leaves.

Downy mildew is more harmful to broccoli, so we first have to choose resistant varieties, and then use mancozeb wettable powder to control it in the early stage of the disease. However, it should be noted that the agent should not be sprayed within half a month before harvesting.

2. Sclerotinia sclerotiorum.

Sclerotinia sclerotinia occurs mainly when broccoli balls and buds open. This disease first manifests itself in the stems and petioles of the above-ground parts of broccoli, and in the early stages of the disease, the affected areas will turn brown and appear water-stained, and as the disease progresses, the leaves will wither and droop, and if the water in the field is too high, then white sclerotia will appear. The main cause of sclerotinia sclerotinia is actually caused by low temperature and rainfall and excessive humidity in the field.

In general, we can control it by improving the permeability of the field, reducing the humidity in the field, and of course, we can also use chlorothalonil for control.

3. Black rot.

Black rot mainly damages the leaves and bulbs of broccoli, and the initial symptoms of the disease are generally manifested in the leaves of the lower part of the broccoli, and black-brown blight will form on the leaves. With the aggravation of the disease, the dead spots on the leaves will gradually expand, forming irregular large spots, and finally spreading to the bulb of broccoli, showing necrosis, blackening, and rotting. Before sowing, the seeds need to be soaked in ammonium dyssen water; The second is to use calcium copper sulfate or calcium hydroxide for prevention and treatment in the early stage of the disease.

4. Diamondback moth.

Diamondback moth mainly refers to the harm of the larvae of the diamondback moth to broccoli, it mainly harms the leaves of broccoli, causing broccoli leaves to be bald and full of holes, which seriously affects the photosynthesis of broccoli, thus affecting the bud growth of broccoli. Then we can use a black light for booby-trapping, and we can also use phosphine emulsifiable concentrate for spraying.

5. Cabbage worms.

The cabbage insects mainly eat the leaves of broccoli, resulting in only a transparent epidermis of the broccoli leaves. In severe cases, it will also affect the flower bulbs of broccoli, which is one of the reasons for soft rot of broccoli. Then for cabbage insects, we can use green worm fungi or pyrethroid insecticides for control.

6. Aphids. Aphids are one of the most common insect infestations of all vegetables, and they can occur throughout the growing season of broccoli, causing serious effects on the normal growth of broccoli. Under normal circumstances, we can use yellow plate trapping to control aphids, and of course, we can also use dimethoate to control them.

Broccoli pests and diseases:

1. Downy mildew, the symptoms belong to fungal diseases, which are more obvious in the process of flower bulb development, the old leaves first develop the disease, and then spread to the young leaves, the leaves turn yellow in the early stage of the disease, and when the leaves are dry and wet, the leaf surface will appear mildew.

2. Soft rot.

Symptoms, is a bacterial disease, broccoli growth in the late stage of more rain, easy to appear lesions in the form of water stains, gradually softened and rotten, produce odor, germs from the wound of the rhizome and leaves invaded.

3. Diamondback moth.

Symptoms: Chuling larvae can only feed on mesophyll, leaving a transparent epidermis, and the larvae that grow up can eat the leaves into holes, and in severe cases, the whole leaves are eaten into a net.

4. Cabbage worms.

Symptoms: The larvae eat the mesophyll, leaving only a layer of transparent epidermis, and only leaf veins are left, which is prone to soft rot when harming the flower bulbs, and the insect feces will also pollute the balls and reduce the value.

Usually read more books on pest control, with experience and methods, in order to control broccoli pests and diseases.

Use some weak acids, such as sodium carbonate. Add water to it and put the leaves in. The leaves are generally better with magnolia leaves. Mix together and cook for 5 minutes, then cool. Just hit the leaf directly with the front of the toothbrush. Don't slant or brush your teeth like we do.

Or at home, it seems that you can soak the selected leaves in rice washing water for a few days, and then use a toothbrush to brush off the rotten mesophyll. Note: When brushing, avoid breaking the leaf veins.

Or boil it in lime water, and wash and dry the remaining leaf veins, which is both environmentally friendly and convenient.

Or use some weak acid, such as sodium carbonate. Add water to it and put the leaves in.

The leaves are generally better with magnolia leaves. Mix together and cook for 5 minutes, then cool. Just hit the leaf directly with the front of the toothbrush.

Don't slant or brush your teeth like we do.

I've done it before. It's beautiful!

1) Choose leaves with a complete shape, the right size, and a reticulated vein, which is the key to success, and the veins are not hard as if they were boiling leaf soup.

2) Brush the leaves with water and boil them in about 10 pieces of sodium hydroxide solution. When the mesophyll is yellow, remove the leaves and wash the lye on the leaves with water;

3) Lay the leaves flat on a tile or glass plate and slowly brush off the mesophyll with a test tube brush or a soft toothbrush. The remaining veins are gently washed in water, dried slightly, and flattened in the book.

At home, it seems that the selected leaves can be soaked in rice washing water for a few days, and then the rotten mesophyll can be brushed off with a toothbrush. Note: When brushing, avoid breaking the leaf veins. This is what our middle school biology teacher told me, and it should be possible! Hehe.

The leaves can be immersed in a concentrated solution of NaOH or concentrated sulfuric acid.

I once saw in a stream in the wild that the leaves were soaked in water for a long time, and then they rotted and only the veins remained.

Well, let's do it together.

Today, I'm going to make leaf vein bookmarks.

I first took out the pad, toothbrush, osmanthus leaves, colored ink, caustic soda, cups, etc.

Please note that this is no ordinary cup, this is a beaker specifically designed for experiments.

It has a cup mouth that helps pour liquids.

I first poured half of the water into the cup, then added caustic soda, and then put in the osmanthus leaves. Then, I put the cup on the gas and burned it slowly, and gradually, the alkali melted, the leaves turned yellow, and the water turned yellow. After it has cooled slowly, I scoop it up again and rinse it with clean water.

Then, I put the leaves on the pad, carefully brushed the mesophyll with a toothbrush, and after brushing for a while, I found that the mesophyll was full of meridians! Finally, I rinsed the osmanthus leaves, cooled them dry, and then soaked them in colored ink, and made a delicate leaf vein bookmark.

1. Lye boiling; 2. Let the bugs eat!

1) Cooking method.

Choose leaves with thick, fine veins and thick mesophyll for later use. Use a beaker to hold 200ml of water, put 5g of sodium carbonate and 7g of sodium hydroxide in the water, and heat it on the fire. After boiling, put the leaves into the cup and boil for about 10min.

In this process, the blades are gently swung with tweezers so that the blades are evenly corroded. After boiling, the leaves are clamped out, put in a glass jar filled with water, brush off the part of the leaf veins other than the leaf veins with a soft-bristled toothbrush (preferably a bristle toothbrush), expose the leaf veins, and then release the bleaching liquid to bleaching (that is, 8g of bleaching powder is dissolved in 40ml of water, and then 6g of potassium carbonate is dissolved in 30ml of boiling water, then the two liquids are mixed and shaken, and 100ml of water is added after cooling, and it becomes bleach after filtration). After bleaching, the vein specimen can be dyed in a variety of colors as needed.

2) Decay method.

Soak the above-mentioned leaves suitable for making leaf vein specimens in water, taking care to place the soaking device in a warm place, so that bacteria can be used to rot the part of the leaf other than the leaf vein. The next steps are the same as the cooking method. When the water rots, it should be noted that the water should be changed when the immersion is smelly.

This method takes a long time to make, but it is simple and easy to implement.

Steps: Steps:

1. Material selection: select leaves with thick leaf quality, moderate size, flat leaf surface and rich leaf veins (such as osmanthus leaves.

Bodhi leaves), wash with water and set aside.

2. Prepare the solution: weigh 35GNOH and 25GN2CO3 into a beaker, and add 1L of water to miscibility to dissolve.

solution to make a solution.

3. Heating: Put the solution into the electric furnace to heat, and immerse the leaves in the solution when it is near boiling.

Turn the degree down and stir while heating; The length of heating time depends on the blade, and you can take one piece after two or three minutes.

The seeds come out and observe until the leaves turn brown (or the mesophyll is shed).

4. Rinse: stop heating, take out the leaves with tweezers, and rinse them in a small plastic bucket filled with water.

Generally more than twice).

5. Brushing: Put the leaves in a plastic plate, add a layer of water, and tilt the toothbrush (about the same level as the horizontal plane.

at a 45-degree angle), gently brush the flesh along the veins, and pay attention when brushing: brush only in one direction (absolutely not back and forth.

brush) so as not to break the leaf veins. When brushing, start from the back, brush the back and then brush the front, and the edge of the main leaf vein.

Use the knock-out method. Brush and dry on absorbent paper (or straw paper).

6. Bleaching: Bleach the leaf veins with 20% hydrogen peroxide (or bleaching powder).

7. Dyeing drawing: You can use red potion, purple potion, magenta and dyes to dye the leaf veins.

to draw on the veins.

8. Pasting and gluing: After drying, it can be glued with paper and glued for preservation.