How to control common diseases and insect pests of Magnolia

Common diseases of Cymbidium and their control methods:

1. Soft rot: also known as rot disease, wiping head disease and so on. Most of them occurred on the lower leaves, and at the beginning, the disease spots showed dark green water stains, and then the disease spots spread into pieces, and the diseased leaves rotted and became soft and sagging, spreading to the roots, resulting in lodging of the whole plant and shedding of the heart leaves.

Prevention and control methods: soil disinfection should be carried out before planting and changing pots, watering should be appropriate, fertilization should be fully mature, and attention should be paid to ventilation and cooling in high temperature and humid season. In the early stage of the disease, 5000-fold diluted solution of penicillin, streptomycin, oxytetracycline and other antibiotics can be used to spray the leaves or the affected area, or 70% methyl topiramate wettable powder 800-1000 times, once every 7 days, 2-3 times continuously. For the rotten root and diseased plants, pour the seedlings into the basin, shake off the soil, remove the rotten parts, and promote the roots after disinfection.

two。 Anthrax: after the onset of anthrax, there are small moist brown spots on the leaves, which gradually expand into round, oval or semicircular spots with wheel lines and black particles scattered on the spots. The disease is a common disease in rainy and humid seasons, especially when watering in the evening and plant placement are too dense.

Prevention and treatment: when the disease occurs, cut off the diseased leaves in time, remove and destroy the diseased body. Spray control with 1000 times of thiophanate methyl, 800 times of carbendazim, and 600 times of anthrax.

3. White silk disease: also known as sclerotia root rot. The disease occurred near the soil, resulting in waterlogged brown soft rot, white silky hyphae covered in the diseased site, mycelium spread on the soil surface, mostly radiant, and sclerotia formed in the later stage. When the damage was serious, the base of the plant rotted and withered and died. The disease often occurs at high temperature and high humidity.

Control method: remove the diseased part, disinfect the base of the plant with 0.1% mercury solution for 5 minutes for 8 minutes, then wash it, soak it in only 50 mg / kg of mononaphthalene acetic acid for a few hours, and replant it in the sterilized wet sand to urge the root. Sterilized culture soil should be used when changing basin soil. At the initial stage of the disease, 50% tophan wettable powder 500 times solution or 50% carbendazim wettable powder 500 times solution was irrigated every 7 to 10 days.

4. Leaf spot disease: at the initial stage of the injury, the leaves appeared brown spots, and then gradually enlarged with large yellow-brown irregular disease spots, sunken, and the edge slightly raised. In the later stage, the disease spot is dry and there are black dots on it.

Prevention and treatment: get rid of the disease and burn it. Foliar spray 50% carbendazim wettable powder 500 times, or 50% carbendazim wettable powder 800 times 1000 times, or 75% chlorothalonil wettable powder 600 times 1000 times, once every 7 days, 3 times in a row. In addition, strengthen management, increase the application of phosphorus and potassium fertilizer, control nitrogen fertilizer, and improve plant disease resistance.

5. Sunburn disease: also known as sunburn disease, mainly due to excessive sunlight directly shining on the leaf surface, killing the leaf cells, light leaf edge whitening, serious leaf tissue necrosis, leaf injury zoom. It often occurs in hot summer or in late summer and early autumn.

Prevention and treatment: in summer, we must pay attention to shading, prevent direct sunlight, pay attention to ventilation and cooling.

The insect pests of Cymbidium are mainly shell insects and some molluscs. The scale insects harmful to Cymbidium are cotton blowing scale, red round scale, brown soft scale and so on. The scale insects gather at the leaf and leaf sheath, prick and suck juice, resulting in withered and yellow leaves and poor plant growth. In addition to eggs, adults secrete wax and induce coal fouling disease. In addition, they are also vectors for the transmission of plant viruses.

Prevention and control methods: gently remove the scale insects from the plant with bamboo needles, toothpicks and matches, or brush them off with sponges or brushes, wipe them off with a wet cloth and coal fouling disease, or wash them with water. During the peak incubation period of nymphs, spray 40% omethoate EC 1000 × 1200 times, or 50% malathion EC 1000 times 1500 times, once every 7 days, 2 times continuously.

Prevention and control methods of common diseases and insect pests in Cymbidium

Many people do not know how to breed magnolia orchids, or improper farming, which often causes the invasion of germs or insect pests, resulting in white silk disease, soft rot, anthrax, and some diseases and insect pests, so how should we deal with them? Next, I will tell you about the common diseases and insect pests and the prevention and control methods of diseases and insect pests.

Leaf Fusarium wilt

The occurrence site is the tip of the tender leaf, and the symptoms develop from top to bottom. In severe cases, the whole leaf turns yellow and wilts. This disease is caused by root neck rot, also known as root rot, which is caused by a fungus that invades the root. It is mainly a physiological disease caused by excessive fertilization or excessive watering of the rhizosphere (root neck) and the cortex and phloem of the stem on the nearby ground.

Prevention and control methods:

1. If it is hypertrophic, it is necessary to change the basin soil and put a layer of fine sand under the root. The basin soil should be loose and rotten leaf soil, and the pH should be neutral.

2. If the water is large, the amount of water should be controlled and the yellow leaves should be removed, and the plant can still return to normal growth.

2. White silk disease

When the disease occurs, the stem near the root appears watery brown irregular spot, cortical soft rot, and then white silk mycelium spreads in the rhizosphere soil surface, then becomes small sclerotia in the later stage, and finally becomes rapeseed, which expands to rot and necrosis at the whole base.

Prevention and control methods:

1. Disinfect the cultivated soil before putting it into the pot. A relatively simple method is to put the culture soil at a temperature of 60 ℃ for 24 hours.

2. Always pay attention to observe the soil surface, find that the white bacteria line is picked out and burned, and sprinkle some lime powder around the disease hole to disinfect it.

3. In the early stage of the disease, 50% carbendazim wettable powder was irrigated on the base of the stem and the soil around the base of the plant, once a week, 2-3 times.

3. Soft rot

Germs often invade from the wound. When the disease occurs, light yellow watery spots appear on the leaves, and then expand into regular disease spots, so that the leaves become brown soft rot ingredients, and there is an outflow of bacterial fluid from the wound.

Prevention and control methods:

1. Once the disease is found, the diseased plant should be separated immediately, the culture soil around the plant should be removed, the diseased part should be exposed, the rotten leaves should be broken, the rotten part should be scraped off with a disinfection knife, and the sun should be exposed properly to keep it ventilated and dry.

2. If there are many rotten plants, all the diseased tissues should be removed, soaked in 5% potassium permanganate solution for 1 hour, rinsed with clean water to dry, plant ash on the cut, plant in a new pot, and placed in a ventilated place where the temperature is not high.

3. Drug treatment can be sprayed or smeared with penicillin or streptomycin or oxytetracycline plus 4000 times aqueous solution, which has a certain curative effect.

IV. Anthrax

The disease often occurs in the rainy, humid and muggy season, and the site of the disease is mostly at the tip and edge of the leaf. At the initial stage, the leaves appeared moist brown spots, and then expanded into an oval and the same wave of the main disease spot, surrounded by yellow, and gradually shrunk and withered in the later stage. The basin soil is too wet and excessive nitrogen fertilizer is easy to cause the disease.

Prevention and control methods:

1. Give flowerpots a well-ventilated and well-lit environment. The pot soil should only be moist and should not be watered too closely. Increase phosphorus and potassium fertilizer and control nitrogen fertilizer.

2. When you find a sign of illness, you should immediately use 50% wettable carbendazim powder plus 800x water to make a solution, or spray with 1000 times water solution of anthrax Fumeijia, spray once in about 6 days, spray 3-5 times will be effective.

Leaf spot

Is the occurrence of small yellow spots on the leaves, disease spots increase, the diameter can reach about 3-5 mm, round; disease spots spread into one, the leaves will wither and yellow. Another kind is on the leaf disease spot is big, the shape is irregular, the yellow brown to the beige, has the wheel pattern slightly, the later stage disease spot back appears the black dot. The above two diseases are due to poor ventilation and parasitism of shell insects, resulting in the weakening of plant growth.

Prevention and control methods:

1. Smear the disease spot with 0.5% potassium permanganate solution, or spray with 50% carbendazim 1000 times solution.

2. When the disease is serious, the injured leaves should be removed, burned, and dried with aseptic skimmed cotton at the wound.

VI. High fever

It is caused by bacterial infection, also known as "wiping head disease". It is most likely to occur in the season of high temperature and humidity.

Prevention and control methods:

The main thing is to pay attention to the cultivation environment. Once the disease occurs, the salvage measure is to scrub the central leaf with cold water so that its temperature no longer rises.

7. Common insect pests

The common pest of Cymbidium is shell insect. When insect pests occur, shell insects often gather on the tender shoots of leaves, absorb leaf juice, secrete a large number of bacteria, make stems and leaves become mildew black, cause soot disease, and make leaves wither. This insect has strong fecundity and can occur for many generations a year. A female adult can often reproduce hundreds of them, which can cause death if no timely control measures are taken.

Prevention and control methods:

Prevention should be given priority to. Usually, we should always pay attention to check the plant, find insect pests, control as soon as possible, in order to prevent spread. In addition to the control of shell insects, both artificial and medicine can be used at the same time. If only one or two leaf tips find pests, they can be manually scraped, sharpened with thin sticks or removed with bamboo cuttings. If there are a large number of nymphs, 25% imidophos emulsion can be sprayed without 1000 times liquid, or 40% omethoate emulsion can be sprayed with 1000-1500 times water solution. Generally, it can be killed by spraying 1-2 times.

Earthworms can also become pests of magnolia. In the young period of the orchid plant, its fleshy root is very weak. If there are earthworms in the basin soil, it will often drill everywhere, injuring the tender root, destroying the function of absorbing nutrition, stopping the growth and development of the plant or causing rotten root.

Prevention and control methods:

Always pay attention to whether there are round soil particles (that is, earthworm excrement) on the surface of the basin soil. if found, you can immediately irrigate it with 50% dichlorvos emulsion and 1500-2000 times water. If there are earthworms drilled after irrigation, remove them immediately; do the same again every other week, and then get rid of the earthworms.

The above is for you to introduce the common diseases and insect pests and their control methods, hope to help you, more household knowledge, please pay attention.

Orchid common pest control originated in the tropical regions of southern Africa, growing under the tree, so it is not only afraid of heat but not cold-resistant, like semi-shady and humid environment, afraid of strong direct sunlight, the best temperature for growth is between 18 and 28 ℃, below 10 ℃, above 30 ℃, growth is inhibited. The gentleman orchid likes the ventilated environment, likes the deep, fertile and loose soil, and is suitable to grow in the loose and fertile slightly acidic organic matter soil. Magnolia is a famous greenhouse flower, which is suitable for indoor cultivation. Cymbidium is often threatened by diseases and insect pests in the process of growing. Zuihua net has sorted out the common diseases and insect pests and their solutions. 1. Disease 1. When the disease occurs, the stem near the root appears watery brown irregular spot, cortical soft rot, and then white silk mycelium spreads in the rhizosphere soil surface, then becomes small sclerotia in the later stage, and finally becomes colored rapeseed-shaped. Expand to rot and necrosis at the whole base. Cause the gentleman orchid to wipe his head. Prevention and treatment methods: the cultured soil should be disinfected before ① is put on the pot. A relatively simple way is to mature the soil. That is, the rotten leaf soil is mixed well with an appropriate amount of water and covered with a plastic film to ferment it, and the heat generated by laughter is enough to kill the bacteria. ② often pays attention to the soil surface and finds that the white bacteria line is picked out and burned, and some lime powder is sprinkled around the disease hole; in the early stage of ③, 50% carbendazim wettable powder is irrigated on and around the base of the plant stem, once a week and 3 times a week. 2. Soft rot pathogens often invade from the wound. When the disease occurs, light yellow water stains appear on the leaves, and then expand into regular disease spots, so that the leaves become as hot as boiling water, and there is an outflow of bacterial fluid from the disease spot wound. Prevention and control methods: 1. Soil disinfection: in order to prevent the occurrence of soft rot in advance, disinfect the potted soil planted with flowers before transplanting. The soil can be disinfected with 0.5% Murray 1% formalin, about 10g per square meter; it can also be disinfected with chloropicrin 60--120g/ square meters or 70% pentachloronitrobenzene 8--10g/ square meters. Used flowerpots and contaminated tools should also be cleaned and sterilized with 1% copper sulfate before use. Do not water too much at ordinary times, lest the basin soil is too wet. 2. Agricultural prevention and control: timely cutting or pulling out the diseased plants and destroying them; do not touch the plants during planting and transplanting to avoid wound infection; pay attention to drainage during the onset of the disease to keep the rhizomes dry so as not to damage the roots, rhizomes and bulbs. 3. Chemical prevention and treatment: 1000 times of agricultural streptomycin or 150 Mel 200 times Bordeaux should be sprayed every 1 month or so to control the spread of the disease. At the same time, when insect pests are found, it is necessary to prevent and control them in time to reduce the wound and reduce the incidence. 3. Anthrax mostly occurs in the rainy, humid and muggy season, and the disease occurs at the leaf tip and the edge of the leaf. Early leaves appear moist brown spots, and then expand into oval and the same wave main disease spot, surrounded by yellow control methods: ① gives flowerpots with good ventilation and light environment, pot soil should only be moist, should not be watered too much and too dense. Increase phosphorus and potassium fertilizer and control nitrogen fertilizer. When ② finds signs of illness, it should immediately use 50% wettable carbendazim powder plus 800x water to make a solution, or spray with 60% anthrax Fumei plus 1000 times water solution, about 6 days spray once, spray 3 Mel 5 times can be effective. In short, the comprehensive prevention and control of these diseases is regular spraying of carbendazim, methyl tobramycin, chlorothalonil, plant streptomycin and so on. Take precautions as a priority. 4. the incidence rule of leaf spot: Cymbidium leaf spot generally occurs in spring and autumn, but it can occur in four seasons in greenhouse. Excessive close planting, poor ventilation and excessive humidity are all conducive to the disease. The disease can also occur if the raw soil that is not yet mature is changed, the unfermented fertilizer is used, the basin soil is not changed for a long time, the fertilizer nitrogen, phosphorus and potassium are not balanced, the amount of fertilizer applied is too large, and so on. Under the condition of high temperature and drying, or when it is seriously damaged by shell insects, the bacteria are easy to invade from stomata or wounds, resulting in the occurrence of diseases. The damaged parts usually occur at the base or edge of the leaf. In the early stage of the disease, there are small yellow spots on the leaf surface, and then the color of the spot gradually deepens, the spot area continues to expand, the edge is raised, there is beige spherical bacterial glial fluid flow, and even sinking, and finally fester, and even rot off the whole plant. Prevention and treatment methods: (1) remove the diseased tissue in time and burn it centrally. (2) change the basin soil in time. (3) it is not easy to spray the plant. (4) spraying from the early stage of the disease to prevent the spread of the disease. The commonly used agents are 25% carbendazim 300 times 600 times (1000 times 50%, 40% suspension 600 times), 50% topiramate 1000 times, 70% mancozeb 500 times, 80% mancozeb 500 times, and so on. Pay attention to the alternate use of agents to prevent bacteria from developing drug resistance. (5) manual disinfestation. The operation should be meticulous and meticulous to minimize trauma and prevent germs from invading the internal tissue of Magnolia. Preventive measures: do not use raw soil, raw fertilizer, fertilization concentration is not easy to be too high, solid fertilizer can not directly contact the root. 5. The incidence law of high fever: this disease is easy to occur in the humid and hot season. The main reason is that germs are brought into the leaves by spraying water or rotten roots and stem tips are caused by long-term wet basin soil. In the early stage of the disease, the root tip growth point first rot, and then gradually spread, causing stem tip and heart leaf rot. After the rotten roots of Cymbidium, the normal physiological function and absorption function of the plant are destroyed, resulting in the increase of temperature in the body, so it is called high fever. The disease develops rapidly, usually within 1-2 days, even within a few hours, the plant temperature can rise from 25 ℃ to 35-40 ℃, and the stem tip of Cymbidium can rot in half a day. Prevention and treatment: if the temperature of the base tissue and leaf seat of Cymbidium is tested with the back of the hand, it is found that it is higher than or equal to the human body temperature, then it means that the orchid suffers from high fever. At this time, rescue measures should be taken to scrub the central leaves with cold water. At the same time, you can also take the orchid out of the basin, rinse the root with cold water, and then put it in a cool and ventilated place to continue to observe whether the temperature at the base of the plant is rising. If it continues to rise, surgery must be taken. The practice is to use a disinfection sharp knife on both sides of the bulb of the central leaf, cut a small crack vertically, then rinse the central leaf one by one with cold water for 10 minutes, and then still observe in a cool and ventilated place. If the temperature does not continue to rise, it means that the problem has been solved, as long as the management is strengthened, the disease will not continue to spread. If the temperature is still rising, it is necessary to check the center blade to see if it has broken heart. 6. the incidence rule of erythema: the back of the leaves showed white or pink yellow and apricot dots at the initial stage of the disease. After discovering the disease, if measures are not taken in time, the spots become bigger and bigger, the color deepens gradually, the spots are sunken and rotten, and the light spots are linked together to rot the leaves, resulting in "wiping the head". The cause of the disease is mostly caused by virus infection. To investigate the source of the virus, most of the fertilizer is not fully fermented and ripened, and the raw fertilizer rots in the soil, resulting in more microorganisms and viruses multiplying in the stem and root base of Cymbidium. These microbes and viruses stick to the root system of Cymbidium to absorb nutrients, which hinders the physiological function of Cymbidium and causes the leaves to show red spots. Prevention and treatment: the red spot of Cymbidium mostly comes from the root. After changing the basin, it is appropriate to use magnetized water to irrigate. 7. The incidence rule of white silk disease: the sclerotia can survive for more than 4 years, so as to survive the adverse environmental conditions, and the disease is serious in the high temperature and humid season. When potting, if the soil is unsterilized garbage soil and vegetable garden soil, the disease will be serious. The disease mainly occurs at the base of the stem near the ground, with brown soft rot, white silky hyphae covering the diseased site and spreading on the soil surface. Later, some of the hyphae were tangled into sclerotia, the sclerotia was white at first, and then turned yellow, reddish brown to dark brown, the size of rapeseed. In serious cases, the whole plant is killed and is easy to pull up. Prevention and control methods: (1) improve cultivation management. Contaminated soil should be taken out of the greenhouse and destroyed. (2) Pesticide control. 8. The incidence rule of soot disease: purple-brown spots appeared in the affected site at the beginning, and then gradually spread into dark brown patches with diameter 1~2cm. At this time, soot appeared in the diseased part, which closely covered the affected area, and the photosynthesis and respiration of the plant were blocked. Prevention and treatment: at the initial stage of suffering from soot disease, Duofu mixture (carbendazim 5% plus thiram 5%) plus 500 × 800 times water can be used to make a solution, which can be sprayed every 10 to 12 days. If the scale insect is found, it can also be made into a solution of No. 20 petroleum emulsion and 50 times 200 times water to kill the shell worm and prevent the disease from spreading. 9. The incidence law of Botrytis cinerea: the pathogen overwintered with the residual plants in the soil, the disease was serious when the greenhouse was poorly ventilated and the humidity was too high, and it was easy to get serious when it was placed too dense, too much nitrogen fertilizer, and the plant tissue became soft, which easily led to the severity of the disease. Perianth, pedicel and leaf can all be damaged. When the perianth is damaged, it produces a waterlogged spot with a diameter of 1 "2", which soon expands and becomes brown and rotten. When it occurs on the pedicel, brown soft rot often falls from the diseased site, affecting seed maturation. Damage to the leaves, often from the edge of the brown soft spots, the surface has wheel wrinkles, can be extended to the whole leaf. When it is wet, it produces a gray mildew layer, and then turns yellowish. Prevention and control methods: use pathogen-free new soil, or soil disinfection after basin soil cultivation, to avoid placing too dense. The greenhouse should be properly heated in winter to avoid excessive humidity. Remove diseased leaves and flowers immediately and dispose of them centrally. Watering or fertilizing should not be too much, it is best to inject water from the edge of the basin. 2. Insect pests (1) scale insects: the shell insects that harm Cymbidium are mainly blown cotton scale, red round scale, brown soft scale and Kang's pink scale. The shell insects live in the leaves and leaf sheaths, pricking and sucking juice, which leads to the withering and yellowing of the leaves and poor plant growth. In addition to eggs, shell insects secrete wax and induce coal fouling disease. In addition, they are also vectors for the transmission of plant viruses. Prevention and control methods: brush off the shell insects with a brush, or wipe off the scale insects and coal fouling disease with wet gauze, or wash them with water. During the peak incubation period of nymphs, 1000-1200 times of omethoate EC was sprayed on the leaves, once every 7-8 days, 2-3 times in a row, or 1500 times of crystal trichlorfon. (2) soft snails: the damaged leaves are bitten into holes or lacerations, making the leaves tilted and crooked, leaving glowing mucus traces where they crawl. The heart leaves of heavy seedlings are eaten, resulting in no growth point, lack of plants and short seedlings, which is a common harmful mollusk in solar greenhouse. The adult flesh of the soft snail is exposed, and the muscle tissue is rich in a variety of glands to secrete transparent mucus. Soft snails like damp and dark, hide in basins and bricks during the day, come out at night to look for food hazards and spawn and reproduce; hermaphroditic. Prevention and control method: kill in the dark and damp place near the victimized magnolia at night; in the soft snail's dangerous period, spread cochlear nematodes in the dark place where the soft snail lives; or use Wanling spray to kill the soft snail. (3) female squirrel: the adult larva lurks inside and outside the basin surface soil and the drainage hole at the bottom of the basin, eats the young new root of Magnolia or bites off the fleshy root, eats the tender leaves and buds on the ground, forms local fester, causes irregular engraving, makes the leaves yellowing, growth damage, lack of short seedlings, and affects the ornamental effect. It is one of the main harmful arthropods in the solar greenhouse. Like dampness, can not bear drought. There is a "false death", in which the worm curls up into a sphere under the collision of external objects. It is motionless and can resume its activity under the direct light or after the removal of the touch of external objects. There is a harmful habit of sleeping during the day and going out at night, which is common under the basin. Prevention and control methods: make use of the habits of squirrel women who are not tolerant to drought, like moisture and afraid of light, clear the excess bricks and broken pots in the gentleman orchid solar greenhouse, pull out the weeds that can be used for concealment, and sprinkle lime around the basin. For severely damaged plants, 2.5% dimethrin EC 2000 times or 20% fenvalerate EC 1000-2000 times could be sprayed. (4) earthworms: although earthworms are beneficial insects of field crops, they are pests for orchid cultivation. Earthworms drill indiscriminately in flowerpots and become fine soil in a short period of time, resulting in soil consolidation. In addition, earthworms can also damage the root system, cause damage to young roots and root hair, affect the absorption of nutrients, and hinder the growth. Control method: spraying dichlorvos 1500-2000 times liquid, or watering with Wanling, can kill the earthworms in the basin. In short, large-scale farming is now mainly for prevention, using avermectin 1500 times liquid sprayed twice every 2 months (7 days apart). I believe that after you have mastered these measures for the prevention and control of diseases and insect pests of Cymbidium, you will certainly be able to breed Cymbidium which is growing well.