Teachers How to control tomato root knot nematodes

Expert answers. 1) Tomato root-knot nematode symptoms show that tomato root-knot nematode mainly harms the underground roots of plants, and fibrous roots and lateral roots are particularly seriously damaged. The diseased root is swollen and boil-like, and the vegetable farmers commonly call it "sweet potato", which is yellowish-white at first, then yellowish-brown to black-brown, and finally rots.

There were no obvious symptoms in the early stage of the shoots of the diseased plants, and only when the root absorption and induction functions were seriously damaged, the leaves turned yellow and even wilted and died. The appearance of root disease is asymptomatic, such as the appearance of furuncularoid neomatous milky white and nearly transparent pear-shaped granules (female nematode body) can be corroborated by the diagnosis.

2) The pathogen is plant parasitic root-knot nematodes, which are common in southern root-knot nematodes, and Java root-knot nematodes. The eggs or 2nd infect larvae of pathogenic nematodes survive and overwinter with the diseased residue left in the soil. It can be transmitted with the help of diseased seedlings, diseased soil, irrigation water, agricultural tools, and human and animal activities.

The larvae hatched from the eggs are the infecting larvae of the second instar, which mostly invade from the root apex after touching the host root and settle in the root tissue.

3) Prevention and control methods: reasonable crop rotation. Conditional implementation of water and drought rotation, with onions, garlic leeks or grass crops, or with susceptible but lightly damaged fast-growing vegetables, in order to reduce the amount of nematodes in the soil, control the disease or alleviate the disease.

Seedlings are raised with disease-free soil. Seedlings are raised with grass or paddy soil or seedbed soil disinfection to cultivate disease-free and strong seedlings and prevent planting diseased seedlings.

Soil disinfection. Before planting, 1 ml of avermectin EC was used for m2, and 6 kg of water was used to irrigate the roots; or irrigate the roots with 500 800 times of 40% chlorpyrifos EC; Or use 3% chlorazophos granules per 667 meters 24 6 kg, mixed with 50 kg of fine soil sprinkled, furrow or hole application, planted and slowed seedlings and then used avermectin 1000 1500 times solution, every 10 15 days to irrigate the roots 1 2 times, has a better control effect.

Apply fully decomposed organic fertilizer, reasonable irrigation, enhance plant disease resistance, remove weeds in time, and reduce nematode reproduction.

Thoroughly clean the field, after harvesting, the diseased remains will be buried or burned deeply, the soil will be turned deeper than 20 cm, and the soil will be watered thoroughly, so that the nematodes will suffocate and die due to lack of oxygen.

Tip board. Tomato root-knot nematodes mainly damage the roots of plants, and the above-ground symptoms are not obvious, and often cannot attract the attention of vegetable farmers. When there are obvious symptoms in the aboveground part, it is no longer meaningful to carry out prevention and control, and the seeds can only be destroyed and restarted, so the soil should be thoroughly disinfected during the annual fallow season.

Root nematode control: Before sowing or planting, soil disinfection is carried out, and 667m2 is sprinkled with 3% methylisothion granules 10-15kg. When the greenhouse tomato is planted, 5kg of 10% Limanku granules, or 300-400 grams of 50% gram of linear phosphorus granules, or 3-5kg of 95% cotton long are applied to 667m2 holes.

The main measures to control tomato root-knot nematode disease are:

First, agricultural prevention and control.

Proper crop rotation. Crop rotation with non-host plants, preferably water-upland rotation for more than 2 to 3 years. Choose disease-free soil for seedlings raising.

Turn the soil deeply. Root-knot nematodes are mostly distributed in the 3 9 cm topsoil layer, and deep turning can reduce the damage. Strengthen field management.

If nematodes occur during the growth of tomatoes, the diseased residues should be thoroughly disposed of, burned or buried deeply; Proper fertilization or irrigation to enhance host resistance.

Second, chemical control.

Apply 1 ml of avermectin per square meter when sowing or planting, dilute it with a small amount of water and spray it on the ground when using it, and immediately turn it into the soil.

He mainly harms the root system of the crop, and a lot of nodules grow on the root system when infected. When the damage is more serious, the plants on the ground will slowly become very slow to develop, and the leaves will become dull and yellow, which will directly affect the yield of the later fruits. There are also some roots that will rot, causing the plant to die, which is really very harmful.

The prevention and control has high temperature prevention and control, and the high temperature stuffy shed will kill all the bacteria and harmful bacteria in the soil.

Chemical control of avermectin has a fast effect, but there are pesticide residues, and it is easy to produce resistance, and the effect is becoming less and less obvious.

Although the effect of biological control and control line is not as fast as chemical control, there is no pesticide residue.

1. For tomato plots with serious root-knot nematodes, take 1 kg of bacillus, first dilute and soak with three to five liters of water for more than 12 hours to ensure that the effective substances are decomposed from the carrier into water, and the roots can be diluted after adding 150 liters of water.

2. 15 days before tomato sowing or planting, select 10% thiazolephos granules, turn deep into the soil after sprinkling, and use 3 to 5 kg per mu, or use strip or ditch application, open a ditch in the middle before planting, apply 2 to kg of the above agent per mu, and then cover the soil steadily, form a medicine belt, if the use of holes, 1 to 2 kg of the above agent per mu, after application, attention should be paid to mixing soil to prevent and control plant roots and direct contact with the agent.

Use nematode crack to apply in the hole before planting, and use 160-200g per mu, that is, the package can be. It is especially reminded that nematodes can only be prevented, and once the disease occurs on a large area of crops, no medicine can cure it. Therefore, it is recommended that even if the nematode has not been found, it is also advisable to use the nematode crack hole to prevent it, and use 40-50g bags per mu.

Tomato root-knot nematode is a particularly common pest and disease, which should be prevented in advance from the beginning of planting, especially in the field of heavy cropping.

1. Planting: 150-300 times dilution of R. solanacearum + 100-150 times dilution of Diliwang + 2 g of Penicillium lilac dipped in roots or bubble trays for planting;

2. Irrigation of seedling water for the first time: 5-10 bottles of Diliwang mu + 10 g mu of Penicillium lavender are irrigated together.

3. The second irrigation: 1-3 bottles of R. solanacium Rick 4. Seedling spray: R. solanacillum Rick 300 times + Wofonsu 600 times dilution spray must be prevented in advance.

Tomato is a vegetable with high multiple cropping index, and long-term continuous cropping and heavy cropping are easy to cause tomato root-knot nematode disease, which is caused by root-knot nematode infecting the roots of tomatoes, and root-knot nematodes will use sharp needles to puncture tomatoes when they invade tomatoes, causing mechanical damage, and a large number of pathogens infect crops through the "wounds". At the same time, the exudates (saliva) of root-knot nematodes will produce chemical effects after entering the root tissues, causing the roots to form nodules, hindering the absorption of nutrients and water by the roots, resulting in poor growth of aboveground plants and reduced tomato yield and quality.

As for how to prevent and control it, it is recommended that vegetable farmers use a combination of agricultural, physical and chemical control methods in order to achieve the best control effect. Specific measures include the following: selection of disease-resistant varieties and raising seedlings in disease-free soils; Before planting, the soil should be deeply ploughed, and slaked lime should be sprinkled to disinfect the soil before sowing; Crop rotation and stubble, if conditions permit, it is recommended to carry out water-drought rotation in re-diseased field areas; Strengthen field management, increase the application of organic fertilizer, increase the content of organic matter in the soil, promote the growth of new roots of crops, and enhance the disease resistance of plants.

In terms of pesticides, it is recommended that vegetable farmers choose Yinghui threadicide.

Vegetable farmers only need to apply avermectin granules such as Ligan sand and wireless in Yinghui threadicide in furrow, hole or whole field before crop sowing or transplanting, and the control effect can last for up to 2-3 months; If the crop is damaged by tomato root-knot nematode during the growth period, it can be irrigated with blue root sand mixed with water and flushed.

After harvesting the crops on the high-temperature stuffy shed, remove the rhizomes, dead branches, and fallen leaves, and plough them in the high temperature season in time

& 41 cm above; About 300 kg of broken straw per mu is applied, carefully pick up the root knots, smooth the sugar, cover the mulch, and irrigate.

After sufficient water, press the front porch and columns tightly, and then cover the shed film tightly, and use the sun to expose it to 20-30 days to make the soil.

The ground temperature at 5 cm reaches 60-70 during the day, and the ground temperature at a depth of 10 cm reaches more than 50, which can be killed.

Root-knot nematode disease and other pathogens and pests in dead soil. Soil pyrolysis must be completed half a month before planting.

and remove the mulch, open the tuyere, and reduce the soil temperature. Before sowing, it is necessary to apply fully decomposed organic fertilizer or raw.

Microbial fertilizers to promote the reproduction of beneficial microbial communities.

Before planting, soil treatment is used with 10% Fuqi multi-granulant kilogram per mu, mixed with 60 80 thousand fine soil.

gram, evenly sprinkled on the surface of the soil, and then turned into a 20 cm layer, can also be evenly sprinkled in the ditch or planting hole, and then shallow.

Mulching, sowing or planting can be done on the same day after application, and the interval between application and sowing and planting can be shortened as much as possible.

After the planting of the root crops with pesticides, combined with the prevention of other diseases, immediately with 70% Emila & 40; Imidacloprid&

g plus 70% antesheng & 40; Zinc & 41; 1 bag & 40; 25 g & 41; Gaprik & 40; Downy mildewcarb & 41; 1 bag & 40; 20 ml & 41; Add.

30% Remittoqing & 40; Nail Frost &; Evil Mildew& 41; 1 bag of water agent & 40; 8 ml & 41; , irrigated roots with 15 kg of water & 40; Can be irrigated 3 4 ridges each.

Fill at least one paper cup of liquid medicine &; 41; to prevent diseases, treat insects, supplement zinc, and promote roots.

Over the years, with the continuous expansion of the tomato area of continuous cropping greenhouses, the number of root-knot nematodes in the soil has gradually increased, making the tomato root-knot nematode disease increasingly serious, and how to prevent and control tomato root-knot nematodes has become an urgent problem for vegetable farmers.

Root-knot nematodes are parasitic pests of plants, and the root-knot nematodes of greenhouse tomatoes are mainly southern root-knot nematodes, which mainly damage tomato roots, with lateral roots being the most serious. The roots of diseased plants affected by the disease will form many nodular-like root knots of different shapes and sizes, which are milky white at the beginning, then turn black-brown, and often rot.

The mechanical damage caused by root-knot nematodes when they harm the roots of tomatoes will reduce the disease resistance of tomatoes, which is conducive to the invasion of other diseases and pathogens (bacterial wilt, wilt, root rot, etc.), and aggravate the disease and lead to serious yield reduction.

Because the tomato root-knot nematode is in the underground damage to the root system, in the early stage of the disease symptoms are not obvious, when the typical symptoms of the disease are manifested, the harm has been quite serious, has missed the key period of prevention and control, therefore, the control of tomato money worm disease should focus on the whole growth period of crop control, to create a non-toxic cultivation environment for tomato, emphasizing comprehensive control measures, mainly agricultural control, supplemented by chemical control.

How to treat tomato root-knot nematode disease, see the following comprehensive control measures:

selection of disease-resistant varieties and raising seedlings in disease-free soils; Before planting, the soil should be deeply ploughed, and slaked lime should be sprinkled to disinfect the soil before sowing; Crop rotation and stubble, if conditions permit, it is recommended to carry out water-drought rotation in re-diseased field areas; Strengthen field management, increase the application of organic fertilizer, increase the content of organic matter in the soil, promote the growth of new roots of crops, and enhance the disease resistance of plants.

In terms of agents, it is recommended to use Yinghui threadicide. Before sowing or transplanting tomatoes, the control effect lasts for up to 2-3 months with avermectin granules such as Ligan sand and wireless in Yinghui threadicide, hole application or whole field sprinkling; If the tomato is damaged by the tomato root-knot nematode during the growth period, the root can be irrigated with blue root sand mixed with water and flushed.

For the tomato plot where root-knot nematodes occur, take 1 kg of bacillus and dilute and soak it with three to five liters of water for more than 12 hours to ensure that the active substance is decomposed from the carrier into water, and the roots can be diluted after adding 150 liters of water.

Speaking of tomato high-yield killers, tomato root-knot nematode disease has to have a name, the disease is caused by the southern root-knot nematode, a plant parasitic nematode, rapid reproduction, strong infectivity, great harm, generally caused tomato yield reduction of 10%, serious yield reduction of more than 40%.

It is understood that the insect overwinters with 2nd instar larvae or eggs left in the soil with the diseased residue, and can survive in the soil for 1-3 years, and the eggs hatch into larvae when the conditions are suitable, continue to develop and invade the host. In the field, it is mainly transmitted by carrying insects and diseased plant residues, farm tools, etc., and can also be transmitted through water flow and farm tools. After invasion, its exudates (saliva) will produce chemical effects after entering the root tissue, causing the roots to form nodules, hindering the absorption of nutrients and water by the roots, causing the diseased plants to underdevelop, grow slowly, and be relatively shorter than normal plants, and the leaves of the plants will be yellow in color and wilt and droop, and even die.

How to understand it?

Root-knot nematodes are aerobic, and sandy soils with high and dry terrain, loose structure, low salt content and neutral reaction are suitable for root-knot nematode activities, so the disease is serious, and the incidence is mild; The longer the continuous cropping period, the more soil insect populations, and the more serious the damage. Unreasonable fertilization leads to the decrease of the content of beneficial bacteria in the soil, the increase of the number of non-beneficial bacteria and the increase of harmful nematodes in the soil.

Therefore, in the prevention and control of tomato root-knot nematode disease, it is recommended that vegetable farmers comprehensively use agricultural, physical and chemical control methods to achieve the best control effect.

1. Crop rotation and stubble, if conditions permit, it is recommended to carry out water-drought rotation in re-diseased fields.

Second, strictly control the seedlings, because the diseased soil manure and agricultural operations are important transmission routes for root-knot nematodes, therefore, after the stubble is changed, start from the source and strictly control the sowing and seedling cultivation. Resolutely put an end to the organic fertilizer made from diseased soil, it is strictly forbidden to bring diseased seedlings into the shed, and the ditching machine after the operation of the sick area should be cleaned before changing the land (field) to open the ditch and cut off the way of nematode transmission through agricultural operations.

3. Strengthen field management, root-knot nematodes generally move in 10 20cm deep soil layer, which can be combined with land preparation to turn the topsoil to less than 30cm, which can effectively control the damage of root-knot nematodes. Increase the application of organic fertilizer to increase the organic matter content in the soil, promote the growth of new roots of crops, and enhance the disease resistance of plants.

Fourth, the combination of drugs. Before crop sowing or transplanting, the control effect can last up to 2-3 months if the avermectin granules such as Ligan sand and wireless in Yinghui threadicide are applied in furrows, holes or whole fields; If the crop is damaged by tomato root-knot nematode during the growth period, it can be irrigated with blue root sand mixed with water and flushed.