Areca leaf spot is very common, what is the cause of areca leaf spot disease?

With the passage of time, betel nut yellow leaf disease continued to spread in the island, and it became more and more serious, from yellow leaf disease to yellowing disease, betel nut tree.

The whole yellow leaf will infect the whole area, and even the betel nut of the entire city and county will change from yellow leaf disease to yellowing, and the tail will appear bald and die directly. On the basis of tree raising, pay attention to nitrogen and potassium.

It has to be added. Fertilization is applied when the Buddha flame bud is exposed, and the flower bud is in the rapid growth stage at this time, this time it is mainly nitrogen and potassium, with calcium, magnesium and phosphorus fertilizer, and trace elements.

Fertilizers are used together to promote the normal growth of flower buds, and then protect flowers and fruits. The leaves wrapped in betel nut are called wattle leaves.

Also known as the leaf of the pipe, it is a vine plant belonging to the piperaceae family, which is mainly used for chewing and has a spicy taste.

Anthrax. Symptom prevention and treatment of yellowing disease symptoms prevention and control of physiological yellow leaf disease symptoms This disease mainly occurs in fruiting trees. Yellow leaves appeared in all plants of the diseased betel nut orchard at the same time, and there was no obvious central diseased plant.

The plant begins to yellowish from the lowest layer of old leaves, and then develops upwards in an orderly manner, and the ants on the betel nut can be removed with pesticides, but it is harmful to human health after consumption. It is recommended that you use lime, sprinkle lime on the betel nut tree, and the ants will be gone.

After betel nut infection with phytoplasma pathogens, the leaves below began to appear mottled and greenish (as if it was deficient), and the leaves were exposed to light at the beginning of the disease, and the mesophyll was light and the leaf veins were green, and the leaves gradually yellowed, the roots turned black, and the growth began to be slow, resulting in low fruit yield, and various data were inferred. However, according to the analysis of industry insiders, the disease is likely to be caused by weather and management deficiencies. If the weather is dry, the root water supply is insufficient, resulting in short and yellow leaves, and for a long time, it will cause weakness and disease, and form bacterial infection.

Occasionally, black lines are closed into small circles. In the later stages of the disease, the root and neck lesions produce fruiting bodies. The fruiting body is flattened, clinging to the diseased area, like a plaster, white at first, then gradually grayish-green, soft in texture, and finally black, charcoal, and brittle. The prevention and control methods are the same as those of betel nut brown root disease.

There are some pests and diseases, and they are not watered in time, they are not exposed to enough light, and the land is particularly dry, so betel leaf spot appears.

It may be that there is no timely watering, no timely fertilization, there may be pest infestation, etc., which will lead to betel nut leaf spot disease.

Brown dots appear on the leaves at the beginning of the disease, and betel nut leaf spot, also known as leaf blight, is one of the common leaf diseases of betel nut. At the beginning of the disease, the leaves of the affected areca nut appear small yellow spots that fade green, and then develop into round or oval brown lesions with black-brown edges and obvious yellow halos on the periphery. After the confluence of multiple lesions turned grayish-white, the leaf tissue was necrotic in a large area, resulting in the weakening of betel nut growth.

In the later stage, there are many small black spots scattered in the lesions, and in the later stage, they expand into irregular formations or long brown spots, with dark brown necrosis lines on the edges, but the lesions are not whorl-shaped, and there are no yellow halos. Usually there are many small black spots on the foliage, that is, the conidia disc of the pathogenic bacteria, which overwinters on the diseased residue with mycelium and conidia, and spreads by wind and rain. The growth of the plant is weak and susceptible to disease.

This disease is particularly severe on the leaflets at the seedling stage, and can occur in Guangdong, Hainan and other places in August and December. <>

The pathogenesis of areca nut stem spot leaf spot is as follows: betel nut orchards are out of control and barren, there are more weeds, poor ventilation and light transmission, and more cases occur in betel nut orchards with high humidity. Generally in young betel nut trees.

The onset is severe. <>

1. Strengthen the daily management of the betel nut orchard, cut down the tall grass and shrubs in the garden, and make the betel nut orchard ventilated and transparent. 2. Increase fertilizer to improve the disease resistance of betel nut plants. 3. After cutting off the seriously diseased leaves in the seriously ill betel nut orchard, use 1% Bordeaux solution.

or carbendazim. or 75% chlorothalonil.

and other fungicide spray control. Betel nut likes high temperatures, and the average annual temperature is 24 26; When the temperature is 16, the old leaves fall off in advance, the plants begin to suffer cold damage at 5, the fruits are black and die at 3, individual plants die, and the plants die severely. For example, in the winter of 1975, Tunchang County, Hainan Province.

In some mountainous areas, the temperature dropped to 60% of 1,1 2-year-old seedlings, 40% to 50% of 3-year-old seedlings, and 20% of adult mother trees. Areca nut likes rainy and humid climate, requiring sufficient and evenly distributed precipitation, and avoiding stagnant water. Relative humidity.

At 60% 80% is beneficial for betel nut growth. The annual rainfall of 1500 2500 mm is suitable for growth, and the area with annual rainfall of 1700 2200 mm and the relative humidity of the air is maintained above 80%. If the annual rainfall is 1200 to 1500 mm, it is necessary to strengthen drought prevention in the winter and spring dry seasons to grow better.

There will be yellowing of the leaves, and there will be a lot of spots on the surface of the leaves, as well as a lot of small holes that have been bitten by insects, and it will also lead to a decrease in betel nut production.

There will be some small brown spots on the leaves of betel nut, which will expand into long strips of brown spots in the later stage, and there will also be dark brown necrotic lines on the edges.

The leaves will have some round lesions, and the leaves will die badly, and the leaves will turn black. The rhizome will become extraordinarily thin.

You can use mancozeb, azoxystrobin, chlorothalonil, allicin, mesomycin and so on. The effect of these drugs is very good, and it can be very good for the leaf spot disease of betel nut.

Allicin, Seaweed Magic Protein Liquid, Plant Disease Clearing, you need to dilute these three drugs together before use, the effect will be more obvious.

In fact, many times we have a certain understanding of the planting of some plants, but when he has some abnormal phenomena, we should take necessary measures when we go in. What are the prevention and control measures? For this problem, for example, pesticides can be used or production can be reduced, let's take a closer look.

1. Spray pesticides

I believe that everyone has a certain understanding of betel nut dental implants, when we can see on the Internet that in some tropical areas, it itself is the main high-yield place of betel nut, and in such an environment, betel nut can grow smoothly, we all know that its growth requires a certain temperature, but if there are some abnormal phenomena, it will lead to more pests and diseases, at this time we can go accordingly. Go to the store to buy some pesticides, and now many pesticides will have a good prevention and control effect on the harm of these pests and diseases.

2 Reduce production

Because if the number of betel nuts planted on a tree is relatively large, it is not only the betel nuts that will compete with each other for these nutrients, but also cause a lot of pests and diseases, because their demand for temperature itself is very high, if they do not get the necessary light. Or if the rainy weather is very frequent, it will lead to a lot of diseased weeds invading, so at this time, we can remove some betel nuts to reduce the yield appropriately.

Therefore, we should pay more attention to this aspect of the problem in our daily life, especially for these growers who plant betel nut, we should have a better understanding of the situation of these areca nut breeding, and we should also take necessary measures in the event of such emergencies.

The simplest and quickest control measures are to prescribe the right medicine, timely spraying can eliminate pests and diseases of pesticides, you can improve the harm of pests and diseases to betel nut, and in ordinary times also need to water and fertilize more, so that betel nut can absorb enough nutrients, can also effectively resist some pests and diseases.

First of all, when planting, you must choose land with relatively fertile and wide soil, and when fertilizing, you must choose farmhouse fertilizer, and do not use fertilizer bought outside. It is also necessary to water more often, to prevent the occurrence of pests and diseases, and if there are small bugs, then be sure to spray insecticides.

You can clean up the garden frequently to ensure that the soil is fertile and of high quality, you can also buy some pesticides to prevent pests and diseases, check the growth of crops, take care of betel nuts more, drive away the surrounding pests, and so on.

Generally, they will choose to kill insects in time, spray some pesticides or apply some organic fertilizers, and sometimes they will choose phosphate fertilizers, nitrogen fertilizers or farm fertilizers.

The symptoms of this disease, Shi Binglan will not overflow yellow or dark yellow pusular ingredients, the leaves will be dark green, the root system will appear to a certain degree of decay, and there will be 1 2 mm spots on the betel nut, the degree of betel nut rot is more serious, and the diffusion area is larger, and the diffusion speed is faster.

The disease mainly infects the leaves of betel nut, causing small dark green or light brown spots on the leaves, and many streaks appear, gradually turning dark brown, and oozing mucus droplets, which eventually leads to the death of betel nut. Leaf.

This disease mainly infects betel nut leaves, so that the leaves have dark green or light brown small spots, and many spots will appear, slowly turning dark brown, will ooze viscous droplets, and finally cause the leaves to die.

The betel nut is inherently unhealthy, and the betel nut pickled in betel nut Hunan is even more tasty, and the numbers written on the packaging are all incomprehensible to the common people. And a lot. I don't think the experts can remember what the numbers are.

There will be some black spots on the leaves of the betel nut, and there will be some pale yellow water behind the spots, and the leaves will wilt from green to light brown, and the betel nut plant will not grow much, and it will be difficult to bear fruit and flower.

The initial symptoms of the leaves are dark green to light brown water-stained oval small spots or short stripes 1 4 mm wide and 5 10 mm long, which are densely arranged into a fence shape when the stripes are often clustered, or converge into irregularly shaped large lesions, with obvious yellow halo circles around them, and the lesions penetrate <>

Blades on both sides. Under suitable conditions, the lesions can expand along the leaf veins to form long spots 1 cm wide and more than 10 cm long, and the lesions become dark brown in the later stage. Under humid conditions, pale yellow, mucous gelatinous droplets (pus) are oozing from the back of the lesions, and the diseased leaves of the seriously diseased plants are cracked, browned and die.

The petiole is damaged, the lesion is brown, oblong or irregularly shaped, the edge is not yellow, the lesion is 2 5 mm deep into the petiole tissue, and its vascular bundles turn brown.

The leaf sheath lesions are brown to dark brown, penetrating both sides of the leaf sheath, no yellow halo, slightly convex, the lesions are nearly round or irregularly shaped, and when the disease is severe, the leaf sheath lesions are accumulated, resulting in the death of the entire compound leaves. The diseased tissue is removed and observed under a microscope, and a large amount of bacteria gushing out of the parenchyma at the incision site can be seen. Diseased seedlings, diseased plants in the field and their residues are the main infections of pathogens**.

Pathogenic bacteria lurk in diseased tissues, and the bacteria overflow from diseased tissues when spring rains begin in the following year, and are spread by rainwater, running water and dew, and <> from betel nut leaves

Invasion of wounds and natural orifices causes morbidity; Insects, contaminated farm tools and farming practices can also transmit disease. Diseased seedlings are deployed for long-distance transmission. The occurrence of this disease is serious in rainy weather, especially in typhoon rain or storm season, which is conducive to the reproduction, spread and infection of pathogenic bacteria, and the disease develops rapidly.

Cultivate or select disease-free and robust seedlings. Strengthen the <> of betel nut plantations

Management, eliminate barrenness, eliminate stagnant water, reasonable fertilization, timely remove the dead plants and their remains in the field for deep burial or burning. Initial insistence is given 1% Bordeaux solution or 500 mg of streptomycin or tetracycline every two weeks. For betel nut orchards with a history of illness, spray with the above agents 1 2 times in time after the typhoon rain.

Some pesticides should be used to prevent pests and diseases, and weeding should also be done frequently, watering should be taken care of, sun exposure should be paid attention to, adequate nutrition should be maintained, etc., so that betel nut bacterial streak disease can be prevented.

Strengthen field management, rational fertilization, prevent partial application of nitrogen fertilizer, remove stagnant water, and remove diseased plant residues; In the early stage of the disease, the following agents and concentrations are generally used: 25% green milk copper 600 times; 72% agricultural streptomycin 3000 times; 25% 600 times of inocracylene; 30% copper oxychloride 500 times, etc., 1 time every 1 day, a total of 2 3 times.

It can be inhibited with drugs, and 72% agricultural streptomycin can be used 3000 times to water betel nut, so that it can effectively prevent betel nut bacterial streak disease.

When planting, we first pour some targeted drugs for this disease in the soil, and then we plant the seedlings well, and then observe its growth cycle, and then continue to spray pesticides.

1.There are many types of betel nut leaf spot disease. Leaf spotted leaf spot leaf spot is a grayish-brown irregular spot that extends from the leaf** to the base, with a dark brown outer ring.

Polychaete leaf spot disease occurs at the tip and edge of the leaf, and then causes tissue death. Anthrax leaves are irregular gray-brown spots with ring stripes. The leaves of the stem spot leaf spot have light brown irregular lesions with dark brown bands on the edges.

Prevention and control methods: pay attention to clearing the garden, often remove dead branches and fallen leaves and burn them, and reduce the source of bacteria; During the occurrence period, it is sprayed with 1 1 150 Bordeaux solution or treated with Ruixin mold; Pay attention to ventilation and light transmission at the seedling stage, and should not be too dense or too shady.

2.Fruit rot causes the green fruit to rot with brown color, resulting in fruit drop. The prevention and control method is the same as that of leaf spot.

3.Fruit spike wilt disease is harmful to the ears and fruits, making them brown and rotten, and small black spots (pathogenic bacteria conidia) are born. Prevention and control methods: immediately remove fallen fruits and leaves on the ground, concentrate on burning, and spray and control with anthrax Fumei and carbendazim during the period of young fruits and green fruits.

4.Root rot is a pest of seedlings, causing their rhizomes to rot in a black-brown color and cause death. Control methods: control soil moisture, irrigate roots with 800 1000 times of 5% carbendazim wettable powder during the occurrence period, and immediately uproot the diseased plants and disinfect the disease holes with lime.

5.The red-veined ear borer is an important pest of betel nut, in addition to coconut and oil palm. Adults lay eggs in the cracks and folds of flower buds, wounds, flower bracts, fruit pedicles, etc.

The first hatched larvae eat flowers and fruits, and can eat up the flower spikes and empty the kernels. The larvae spin silk and make insect feces and rodent chips into worm tunnels, which hide in them. The flowering period and the young fruit stage are the most harmful, resulting in fruit drop.

The insect is common in the betel nut production area of Hainan, and the young trees that have just borne fruit are particularly harmful, causing a direct threat to the yield, according to rough estimates, the loss caused by the insect can be as high as 40% or more. More than 8 generations are born on Hainan betel nut trees every year, and there is no obvious overwintering and summer stage. In autumn and winter, after the betel nut is harvested with green fruits, under the condition of poor food conditions, it will damage the heart leaves, causing baldness or death.

Prevention and control methods: pay attention to picking up fallen fruits at any time, especially after harvesting fruits in autumn and winter, combined with clearing the garden, clearing the fallen fruits and dead branches and leaves out of the garden and burning them to reduce the source of insects; In the case of serious plots, combined with fertilization in spring, 3% carbofuran granules are applied kilogram plants (small trees can be reduced), which can basically control the flowering and young fruit stages, and can also control other pests. Or spray twice a month and a month, with BT emulsion 100 times plus 3% neem oil or BT emulsion 100 times plus 10% 10 microliters of dibaco spray.