What does a cucumber root knot nematode look like? What to do?

What does a cucumber root-knot nematode look like? What to do? The symptoms of cucumber root-knot nematode disease are mainly manifested in the roots.

The symptoms of mildly diseased plants are not obvious, while the severely diseased plants are short, stunted, and have poor fruiting. In drought conditions, they wilt at noon. After the diseased seedlings are removed, nodules of different sizes will appear on the lateral roots or fibrous roots.

Some look like beads, making the roots thicker. Dissect the root knot and you will find a small milky white root knot nematode in the diseased tissue. Prevention and control:

Methods such as deep ploughing, drying soil, idle irrigation, and increasing the application of decomposed organic fertilizer can be adopted.

Symptoms of root-knot nematodes.

Cucumber root-knot nematode is a soil-borne disease that usually occurs on the lateral and fibrous roots of cucumber roots. We can see with the naked eye that the cucumber roots with root-knot nematodes are thickened and have nodules of varying sizes on them. At the same time, cucumber plants are relatively short and weak, and there are not many cucumbers, and they are relatively small, which is a bit like cucumber plants lack water and fertilizer.

Conditions of activity in cucumber root-knot nematodes.

The symptoms of cucumber root-knot nematode were mentioned earlier. Now, let's talk about the conditions for root-knot nematode disease. In general, cucumber continuous cropping fields and plots with long continuous cropping period are more prone to root-knot nematode disease without corresponding control measures.

The suitable temperature for root-knot nematode reproduction is generally around 26 30. When the soil temperature is above 40 or below 5, the activity of root-knot nematodes is relatively small.

How root-knot nematodes are transmitted.

Root-knot nematodes are usually spread by bacteria carried from water during diseased soil, seedlings, or irrigation. When the pathogen of root-knot nematode is brought into the soil, it overwinters in the soil. When the temperature rises the following year, when the temperature reaches its active conditions, it invades the roots of the cucumber and then forms root nodules.

This affects the growth of cucumber roots and the absorption of nutrients.

Prevention and control methods of cucumber root-knot nematode disease.

1. Implement crop rotation: when planting cucumbers, they are generally not continuous cropping in the same plot, but they can be rotated with vegetable crops such as garlic, onions, peppers, and leeks. For example, if the previous crop was a plot for growing rice or aquatic vegetables, it is better to use it to grow cucumbers.

Therefore, when planting cucumbers, they are generally rotated with other crops to reduce the occurrence of pests and diseases.

2. Field management: cucumber seed seedlings should choose disease-free soil as a seedbed for seed seedling. When applying farmyard manure on cucumbers, it should be applied after it has been fully fermented and ripe.

After harvesting cucumbers, removing weeds and diseased plants from the field and turning the field deep to dry out the soil can also reduce pests and diseases.

It will lead to stunted growth, the plant is relatively short, there will be some nodulous, we must use pesticides on time, and we need to pay attention to the treatment of the soil.

There may be some tumors on the roots, and there may be some decaying places, so it is necessary to disperse the chemical agent in time, and also pay attention to remove the problematic part.

It's a southern root-knot nematode. You can remove it by disinfecting or anti-inflammatory injections, or you can use some pesticides to treat it.

Cucumber root nematodes can be irrigated with ivermectin, thiazolephos, and Bacillus thuringiensis, and the use of chitin can inhibit the occurrence of nematodes.

Yes, how many cases there were, what severity, what were used. It's in the middle of the year.

Cucumbers have nematodes** Relatively some pesticides** are still OK, other words should not work, specifically pesticides** can.

Introduction: With the development of the times and the improvement of the quality of life, people are more and more concerned about food safety. And want to eat greener and healthier organic vegetables, then according to the current economic development, organic vegetables are in short supply, so farmers around the country have risen to plant greenhouse vegetables, in order to better promote the operation of the market.

Recently, some careful netizens have found that many greenhouse vegetables and cucumbers have root-knot nematode disease. <>

One:Why do cucumber root-knot nematodes appear in greenhouse vegetables

We all know that greenhouse vegetables are for the supply of the market. However, recently, the disease problem of greenhouse vegetables has become more and more seriousSeriously,Here's whyBecauseIt is caused by the occurrence of cucumber root-knot nematode infestation。Egg-sacked clumps or scattered root knots excreted by the older larvae of root-knot nematode ants overwinter in the soil.

The larvae that can hatch from eggs are very active, but the temperature in Dapeng is close to 20, and he begins to damage the root knot of cucumbers, and if the soil water is always permeable and the root knot nematode is even more powerful. This led to the greenhouse of vegetablesThe losses are huge.

Two: HowScientific and effective prevention and controlRoot-knot nematode infestation?

In order to better restore the greenhouse vegetable economy and better cater to the market operation. It is necessary to use scientific and effective prevention and control measures to stop losses in time. In preventing the harm of cucumber root-knot nematodes can be carried out on the soil to be deeply disinfected, using high temperature to kill nematodes, and adoptedAn airtight canopy partyAct

And then againAdopt the application of organic fertilizer, make good use of livestock manure, and cooperate with crushed straw as organic fertilizer to improve soil structure and improvementSoil pH。to ensure the health of the epidermal tissue of cucumber roots and whiskers, and to resist the erosion of nematodes. It is also necessary to strengthen pastoral management, concentrate on burning or burying pathogens, and reduce the occurrence of insect pests.

To a certain extent, it can be prevented with the help of pharmaceuticals, which is the so-called right medicine. However, it is not recommended to use pesticides in large areas, which will affect the food safety of crops. <>

Three: we should also grasp the prevention and control of cucumber root-knot nematodesBest time.

SummerWhen the high temperature state can be used to stuff the shed, so as to achieve high temperature sterilization. Large-scale areas are cultivated in rotation. We must grasp the best time to prevent and control clean and ready-made, that is, the summer level, because the summer level is hot and the root-knot nematode is afraid of high temperatures to take the stuffy shed method, resulting in the highest temperature in the shed At this time, the root-knot nematode is the best season.

Pesticides are used for prevention and control, pesticides can solve a lot of problems of pests and diseases, and can also play a good role in prevention and control.

It should be watered frequently, pests and diseases should be paid attention to, and reasonable nutrition should be obtained, or some pig manure, cow dung, tangled with some wilted branches and leaves, etc., these are all ways to control it.

Cleaning up the field, crop rotation, deep ploughing and drying, timely removal of diseased residues, cultivation of disease-free and strong seedlings, etc., all of which can prevent cucumber root-knot nematodes.

Prevention and control methods.

1) Flooding. In areas where conditions permit, 10 cm or more of the soil layer can be silted for several months, which can play a role in preventing the infestation, reproduction and growth of root-knot nematodes.

2) Deep flipping. Root-knot nematodes are mostly distributed in the 3 9 cm topsoil layer, which can be reduced after deep turning.

3) Implement crop rotation. Choose disease-free soil for seedlings raising. Celery, cucumber, and tomato are high-sensitivity vegetables, and green onions, leeks, and peppers are disease-resistant vegetables. Disease-resistant vegetables can be planted in diseased fields to reduce losses.

4) Soil disinfection. This method is mainly used in seedbeds. The agent should be applied to the soil 15 25cm deep from the soil surface 2 3 weeks before sowing, and should be kept moist before application, and the soil should be compacted after application to achieve the purpose of fumigation and insecticide.

The effective agent is 80% dibromochlorohydrin EC 1:10 times liquid, 2 3 ml dilution or stock solution per hole, or 20% Yishuibao granules. For nematodes during the growth period of cucumbers, 50% phoxanthion EC weight 500 times liquid, 80% dichlorvos EC 1000 times liquid, 99% trichlorfon crystals 800 times liquid to irrigate the roots, each plant is filled with kilograms, generally 1 time.

5) Application of lime nitrogen, in recent years, the application of lime nitrogen in the facility, and the stuffing shed, has received a certain effect, but because the lime nitrogen is too alkaline, we must pay attention to safety when applying, and at the same time, because the application of lime nitrogen is easy to cause the increase of soil alkalinity, it is necessary to carry out proper management.

6) Strengthen cultivation management, thoroughly deal with diseased and residual plants, and concentrate on deep burial; Reasonable fertilization and irrigation can delay the symptomatic manifestations of diseased plants or reduce losses.

Symptoms: cucumber root-knot nematode disease mainly harms the root of cucumber, after the damage can form large and small nodulous root knots, which begin to be milky white, turn into light brown in the later stage, cut the root knots, there are very small milky white nematodes, and its aboveground symptoms are plant dwarf, stunted development, and wilting can appear around noon when drought and water ** are insufficient. In general, weak new roots can grow on the root knots, and if they are infected again, root knot-like tumors will be formed.

Cucumber root-knot nematode disease mostly occurs on lateral roots and fibrous roots, forming nodules of different sizes. The nodules are white and smooth at the beginning, and then turn yellowish-brown to black-brown, with rough or even cracked surfaces, and rot in severe cases. The nodules are asymptomatic in appearance, and a white piriform body (female nematode body) slightly larger than the needle can be seen on autopsy.

The symptoms of the aboveground part of the diseased plant are not obvious in the early stage, and with the aggravation of root damage, the leaves are yellow, like lack of water and fertilizer, and in severe cases, they wilt or even die in case of high temperature. The disease is more severe in sandy soil or continuous cropping (color Figure 9).

Prevention and control methods: 1) If the nematode is a serious area or field, the diseased residue and stump should be removed immediately after harvesting, buried or burned deeply, and the field should be turned over and dried.

2) Nematodes found in the shed protection area should be sterilized at high temperature, and the specific method should be referred to cucumber cataplexy.

3) 150 500 kg of fully decomposed dry chicken manure was applied every 667 m2, which had a high control effect.

4) Pharmaceutical prevention and control. You can use 30% special emulsion to remove the line, 300 350 times the amount of water per 667 meters 2 kilograms of water poured in the sowing ditch, such as using 50% special powder to remove the line, the dosage is the same as above, mixed with 30 kg of fine dry soil, sprinkled in the sowing ditch, and then sown and cover the soil. If nematodes occur during the growth period, they can be combined with cultivated loose soil and applied 1 more medicine.

The dosage was increased by 1 or 2 times compared with before. In order to prevent pesticide damage, it should be tested before use, and then applied in a large area after determining that the variety has no pesticide damage.

(1) Harmful symptoms.

It is mainly harmful to the roots of cucumbers and other melons and vegetable crops such as nightshade and cruciferous. When the lateral roots or fibrous roots of crops are infected, they produce nodular-like root knots of different sizes, ranging from the size of rice grains to mung bean grains, and the size of a ping-pong ball. Dissecting the root knot, there are many tiny milky nematodes in the root knot tissue.

Weak new roots can usually grow on top of the root knots, but they will be parasitic and infected again, forming root knots. After cucumber infection, the aboveground parts show dysplasia, and the symptoms vary according to the severity of the disease. The symptoms of mild diseased plants are not obvious, the growth of severely diseased plants is sluggish, the leaves are gradually yellowed, the plants are dwarfed, wilted at noon, there are few melons, and the growth of melon strips is slow.

When the disease is severe, the leaves gradually dry up until the whole plant dies.

2) Prevention and control methods.

Implement water-drought rotation, grain and vegetable rotation or flooding method. Changing a crop of rice to a seriously diseased vegetable field can completely eradicate residual eggs and live nematodes in the soil. Silting 10 cm of the surface of the ground or deeper soil layer for several months in conditional areas can effectively prevent and control the infestation, reproduction and growth of root-knot nematodes, although root-knot nematodes are not dead, they cannot be infected.

In the fields where root-knot nematodes occur severely, the implementation of 2-year or 5-year rotation with C. japoire can obtain more desirable results. The implementation of vegetable field rotation with corn, wheat, green onions, garlic, etc., can significantly reduce its damage.

In the seriously diseased field, when planting, apply 10% Limanku granules in the hole, 5 kg per mu, or irrigate 1000 1500 times the liquid of 2% avermectin, 100 200 ml per plant, which has a good control effect.

Soil application of biological fungus preparations such as Qi multi-year, biological multi-effect Qi, Wangdefeng, Duolibao, etc., 500 1000 grams per mu, can significantly reduce its damage.

Cucumbers cultivated in protected areas, and when they are stubble changed from mid-July to mid-August to mid-to-late August, they can be completely eliminated by using the high temperature season to carry out high-temperature stuffy sheds. For detailed control methods, please refer to the section on cucumber cultivation in greenhouses.

Cucumber nematode medicine in greenhouses is sold there.

You can pick it up, there are not many good medicines, they are all blown, there is one brocade, self-matched, and the amount is not large.

Absolutely. <>

Cucumber cultivation techniques.

Site preparation. 5 cubic meters of organic fertilizer for land preparation and fertilization, 25 to 30 kg of superphosphate or 10 to 15 kg of diammonium phosphate (5 kg of superphosphate per cubic meter, 2 to 3 kg of diammonium phosphate per cubic meter). Before planting, plough the furrow, the width of the furrow is more than 15 cm, and it is covered with mulch.

Colonization. Determination of planting period: planting as soon as possible on the premise of ensuring that there is no freezing after planting, and planting in Chengde area is generally in late April and early May.

Temperature index requirements: the minimum night temperature is higher than 5, and the soil temperature is higher than 12 at 0 to 10 cm. The cucumber in the autumn dew field adopts the method of live broadcasting.

Planting density: 4000 to 4500 acres, planting in large and small rows, small row spacing 40 cm, large row spacing 80 cm, plant spacing 25 to 30 cm, planting with dark water method.

Manage. Sockets. After planting, the shelf should be planted as soon as possible, and the seedling should be pumped by wind, and the shelf can be a flower stand or a herringbone frame, about 8 to 10 cm away from the root.

Tie vines. The "8" method is used to tie vines to prevent abrasion of stems and vines and sagging stems. Every 2 to 3 knots are tied, should be carried out in the afternoon, the stem vine is easy to break in the morning, the tightness of the vine should be suppressed and the weak should be strengthened, and the growth of the plant should be tied a little tighter, and the height of the growth point is consistent.

Pruning and pinching. For the main vine, all the side branches should be removed, and one or two leaves should be left after the side vine is fruitful, and all the tendrils should be removed. When the stem exceeds the head of the shelf, it is necessary to pinch the tip in time to promote the growth of the lower melon, and the method of twisting the tip can also be used to inhibit the growth of the upper part.

Fertilizer and water management. Timely watering and cultivating, the amount and frequency of water depends on the weather and growing period. Slow seedling water is watered 5 to 7 days after planting; water control, cultivating, and squatting seedlings before sitting on melons; When the root melon is 10 to 12 cm long, water the melon; Watering during the fruiting period is done every 5 to 7 days.

The principle of top dressing is that the front is light and heavy, a small amount of many times, urging melon fertilizer to be applied after the root melon sits, and the melon fertilizer is carried out after the root melon is harvested. Promote the use of organic fertilizer topdressing.