Symptoms and prevention methods of carrot root knot nematode?

Due to the recent good market of carrots and the relatively simple cultivation management, it has attracted many farmers to plant and cultivate in recent years. However, many growers have been extensively managed for a long time and do not pay attention to the prevention and control of root-knot nematodes, resulting in more and more serious damage to carrot root-knot nematodes. What kind of medicine should be used to control carrot root-knot nematode?

What are the symptoms of carrot root-knot nematode and how to prevent it?

Carrot root-knot nematodes can be transmitted through diseased seedlings, diseased soil, diseased fertilizers, water flows, etc., and the primary source of infection is carrot seedlings carrying root-knot nematodes. Although there is no obvious abnormality in the aboveground growth, many nodulous root knots can form on the nutrient absorption roots. The newly returned larvae can spread a short distance in the soil, invade the root system of the newly transplanted carrot seedlings, parasitize in the root tissue to feed on the damage, and gradually develop into an elderly insect, and then the elderly insect lays eggs, and the larvae invade the root tip, and so on.

After being harmed by carrot root-knot nematode, in addition to the formation of root knot nodules, black roots and root rot will also occur. Root rot is caused by poor root vigor and long-term inability to absorb nutrients; Second, carrot root-knot nematodes cause mechanical damage to the root system when they are invaded, and the wound provides favorable conditions for root rot and other diseases, thereby causing root rot.

Growers can combine dry crops with "root Shangya" fertilizer or soil hole application and whole field application before carrot sowing or fertilization, the control effect can last for 2-3 months, and the control effect on carrot root-knot nematode is better, and the growth recovery is fast.

The symptoms of carrot root nematode are mainly when the carrot is small, and then the root nematode drills into the root, and then the seedling will die.

There are many semicircular nodules on the roots, and there are many irregular galls on the lateral roots, which are white at the beginning of the disease and turn brown after that.

The carrot leaves will have some yellow, and the carrot leaves will also have some black spots, if it is severe, the surface of the carrot will also be uneven, and there will be some brown spots or rotten smell.

After the root is diseased, many swollen semicircular nodules are scattered on the straight roots; multiple nodular irregular round galls on lateral roots; The straight roots are forked and branched. The tumor is white at first, then browns, and is born 5 cm near the ground.

I don't know much about this, because I don't usually know much about this aspect, so you can ask some farmers or professionals.

Root-knot nematode disease occurs in carrots because the underground roots are yellow and weak. After the occurrence of root-knot nematode disease, certain prevention and control methods can also be adopted. For example, when transplanting vaccines, seedlings should be raised with disease-free soil, and when cultivating disease-free seedlings, diseased seedlings should be eliminated during the planting process.

Moreover, the diseased planting land should be rotated with food crops, and the results of water-drought rotation will be better, which can reduce the number of nematodes in the soil and reduce the damage of the next stubble. <>

If there is a premise for turning and drying soil, you can also operate the summer fallow period to carry out turning and drying the field, and carry out turning every 7 10 days or so, lasting 2 or 3 times, and then you can kill the nematodes on the surface. It can also be flooded in the field for a month, which can also kill the nematodes on the surface. Using 50% depowdering agent, according to every 1000 square meters with trillions, kilograms of medicine and rare earth 30 kilograms mixed together, prepared into medicinal soil scattered in the ditch, and then sowing and turning the soil, can also be applied in the process of sowing and planting 10% of the full library granules.

It has a long history of rooting agents for sick pigs during the onset period, which can be used with 50% phoxanthion EC and 1500 times the solution. Generally, it is necessary to water before filling the medicine, which can improve the efficacy of the medicine. Carrots are also called wild carrots and have many names.

The roots of carrots are thick, conical or cylindrical, the flesh is purple or yellow, and the petioles are very long, originally produced in Central Asia, and have a history of more than 4,000 years. <>

At the same time, the nutritional value of carrots is very high, not only can be made into dishes, but also can be eaten raw, and they will be very delicious while making different dishes. However, many children do not particularly like to eat carrots, for the sake of children's health, we must let children have a nature of carrots, after all, there is a great nutritional maintenance for the body.

Generally, the terrain is high and dry, the soil is loose, the salinity is low, and the heavy stubble may make the nematode heavier. The moisture content of the soil in the field is an important condition that affects the hatching of eggs and the reproduction of nematodes, and the nematodes reproduce quickly under the condition of soil moisture of 35 45, which is easy to accumulate in large quantities in the soil.

The reason for this occurrence is that this knot nematode is parasitic in the soil at the beginning, and when the carrot is planted and grows to a certain extent, this knot nematode will enter the carrot's body, causing this carrot root knot nematode disease.

This is because there is a pest and disease in the roots of carrots, there is a lot of water here, the temperature is relatively high, and the roots rot, so this insect is produced.

The stubble arrangement and planting environment of vegetables grown in greenhouses are especially suitable for the survival conditions of root-knot nematodes, which means that the incidence of root-knot nematodes in greenhouse vegetables is relatively large. These diseases and insects mainly attack the root system of tomatoes, when the root system is damaged, the supply of nutrients and water is insufficient, resulting in the dwarf and wilting of the plants, the growth is relatively slow, and the tomatoes produced are small and deformed. If remedial measures are not taken in time, it will lead to red tomato nematoes refers to a kind of nematoes that harm the normal growth of tomatoes, and tomato root nematoes often mainly harm the roots of tomatoes, causing the normal respiratory function of tomatoes to be seriously affected, resulting in the root of tomatoes appearing in the shape of a rosary with milky white nematoes; Infected plants are thin and short, with poor growth and few and small fruits.

<> root-knot nematodes are mostly distributed in soil layers of more than 20 cm. It spreads through diseased soil, watering, and farming activities, so it is necessary to start from the soil layer in order to completely root the nematode. Tomato varieties resistant to root-knot nematodes were selected to reduce the probability of tomato infection after colonization.

At present, tomato seedlings are mainly raised using factory substrate seedlings and individual seedlings of farmers, seedling substrate and seedling soil do a good job of preventing nematodes, cultivate healthy bodies without insect infection, male worms into threads, female worms into pear rows, mostly buried in the host tissue, the roots of crops, dangerous to crops.

The damage is extremely serious, tomatoes are also in it, when tomatoes are harmed by root-knot nematodes, the plant growth gradually weakens, the growth point grows slowly, the lower leaves and roots carry out U-shaped fold to determine the feeding site, after the root feeding and development, the white female worm containing eggs is formed and exposed to the root surface, and then falls off in the soil to form brown sporangia dormant in the soil for overwintering, and other conditions are suitable to start a new round of infection cycle, and the sporangia can be controlled with chemical drugs after the large-scale outbreak of the root-knot nematode in the soil, such as avermectin, However, it can only kill adult insects, treat the symptoms but not the root cause, and will develop resistance. Therefore, after using up the chemical drugs, you can use Penicillium lavender, biological insecticide, and insist on using it.

In agricultural control measures, we strictly control the transmission route of root-knot nematode. For example, agricultural control measures such as removing diseased residues in the field, doing a good job of soil disinfection, selecting disease-free seedlings for sowing, and reducing flood irrigation can effectively reduce the spread of root-knot nematodes and the distance traveled in the soil. Finding insect pests, removing diseased plants in time, and disinfecting the soil near the growth of diseased plants with quicklime can play a role in killing the source of insects.

Finding ways to control the harm of root-knot nematodes to the lowest extent is one of the effective measures in agricultural control.

Increasing some beneficial bacteria in the soil also has a good control effect on carrot root-knot nematodes. On the one hand, it can directly parasitize in root-knot nematode eggs, causing the eggs to not hatch, and can also affect the normal reproduction of female adults, on the other hand, the secretions also have a certain nematicidal effect.

You can go to a professional to arrange how to sow the seeds. There is also the timely spraying of some dichloropropylene.

In recent years, root-knot nematodes have become a big problem for growers, and when root-knot nematodes, not only the investment is high, but also difficult.

Root-knot nematode is a worldwide pest, generally the damage greenhouse can reduce the yield by 20%-30%, the serious greenhouse yield reduction can reach 60%, or even extinction, the degree of harm is quite serious, and once it is difficult to introduce.

So, is there any way to control root-knot nematodes? What kind of medicine is good for root-knot nematodes? Let's take a look.

Prevention and control methods of root-knot nematode 1, rotation of vegetable fields with root-knot nematodes, the implementation of crop rotation, especially rice and onion, garlic and other rotation, the control of root-knot nematodes is better.

Do not rotate with nematode-prone vegetables such as eggplant, tomato, celery, lettuce, carrots and other vegetables.

2. Seedbed disinfection or soilless seedling seedbed is one of the important ways for root-knot nematode transmission, if the seedbed is not treated, it is easy to spread root-knot nematode to the field, and the crop is harmed by root-knot nematode in the early stage of its yield.

The use of soilless seedlings is an important measure to avoid root-knot nematode damage.

If the seedbed area is very large, the seedbed disinfection measures can be adopted, and the 35% Weibaimu water agent (8-10kg mu) is fully mixed with the soil, and then covered with plastic film for fumigation.

3. Irrigation of 10-15cm deep in flooded insecticidal and seriously ill fields for 20-30 days will suffocate nematodes due to lack of oxygen.

This one-season rice plant not only kills nematodes, but also does not cause the field to be barren.

4. Deep turning root knot nematodes are mostly distributed in the topsoil layer, and deep turning can reduce the damage.

Before sowing, deep ploughing is more than 25cm deep, and the possible nematodes are turned deep into the soil, which can reduce the damage.

5. The use of root-knot nematode-resistant varieties or rootstock varieties to choose disease-resistant or disease-resistant vegetable varieties can greatly reduce the damage of various diseases.

In comparison, there are varieties with high resistance to root-knot nematodes in Biyouzhou, and new Israeli tomato varieties FA-593 and FA-1420 are more resistant to nematodes.

What medicine is good for root-knot nematodes, root-knot nematodes can be infected, easy to infect, and can be controlled with Root Sand.

Remove the mound of soil attached to the root system, cut off all the nodules on the root system, and destroy it. Attack.

Prepare the emulsifiable concentrate mixed with 1500 times the water, dilute the roots of the soaked plants, and be careful not to soak on the leaves, so as not to burn the leaves.

After soaking, dry the root system of the plant, prepare a new pot soil for planting, and when potting, the hand cover can be mixed with 2 spoons of root sand granules in the soil to prevent root-knot nematodes**.

1. The insect pests of radish mainly include aphids, cabbage worms, vegetable borers, diamondback moths, yellow bendt jumping beetles, etc.

1. Aphids mainly harm the leaves of radishes. Flocks gather on the back of the leaves and heart leaves to suck the sap, causing the affected leaf margins to curl back, the leaves to shrink, and gradually lose water and wither yellow, so that the plants are short, stunted, until they die, in addition, they can also spread viral diseases. It can be sprayed with 10% imidacloprid wettable powder 1000-2000 times or 50% aphid mist wettable powder 3000-4000 times liquid spray.

2. The adult cabbage worm lays eggs on the back of the leaves, like vertical wheat grains, which harm the vegetable leaves after hatching and eat a lot of nicks. With the increase of insect age, the damage gradually increases, and sometimes only leaf veins remain, affecting the growth and development of plants. And feces contaminate the foliage and spread soft rot.

The 1-3 instar larvae should be treated with pesticides when there are many pesticide controls, sprayed with a high-efficiency emulsion (8000 IU microliters) 1500 times liquid, add human laundry detergent when preparing the liquid, and choose a cloudy day with a light temperature higher than 15, or apply it after 4 pm on a sunny day; Or spray with 5% anti-Taibao emulsifiable concentrate 2000 times.

3. The adult vegetable borer lays eggs on the young leaves such as the heart leaf, and after hatching, the first leaf is harmed, and the second instar wears out the leaf surface to spit the silk and decorate the leaves, so that the heart leaf dies, and the 4-5 instar is bored by the heart leaf or petiole roots, and the victim plant dies. When the eggs are caught in the incubation period and the heart leaves are first damaged, pesticides are applied for prevention and control, and 2500 times of kung fu emulsifiable concentrate is sprayed; or 50% phoxanthion EC 1000 times liquid spray.

4. The young larvae of diamondback moth feed on the mesophyll, leaving the epidermis, and the damaged leaves show transparent spots, and after the 3rd instar, the leaves are eaten into holes and notches, and the whole leaves are eaten into a net when they are serious. The larvae at the seedling stage like to concentrate in the heart leaves, which seriously affects the growth of plants. It can be sprayed alternately with high-efficiency emulsion (8000 IU microliters) 1500 times, 5% anti-Taibao EC 2000 times, and deltamethrin EC 2000 times.

5. The adult bites the leaves, forming many small holes, when the damage is severe, the seedlings die as a whole, and the adults also bite the flower buds and tender English of the radish that are left behind. Fruit stalks, tender shoots, resulting in reduced yields. The larvae eat the root bark and bite the fibrous roots, which affects the growth of the plant and the commerciality of the fleshy roots.

The prevention and control methods are: pay attention to cleaning the countryside after harvesting, and plough the dry fort and frozen fort in time to reduce the source of insects; Spray with 1000 times of 50% phoxanthion emulsifiable concentrate.