When does the radish aphid infestation usually occur? How to prevent it?

In September, many radishes planted by farmers have also sprouted and are about to start germinating. Due to the high yield of radish, many farmers think that in the management of water and fertilizer management during the succulent root expansion period, farmers think that nitrogen fertilizer can be used more to achieve high yield, in fact, radish and other vegetables are very different. When fertilizing is applied, the farmer has changed.

At the beginning of the use of a single nitrogen fertilizer, I found that the inside was very empty and the taste was not good, and now it is the period of swelling of fleshy roots, supplementing a variety of nutrients. In addition to this, there is another important period for the high yield of turnips, which is the extended sitting period of turnips. Many farmers say that when is the meditation period for turnips?

The leaves of the rosette stage are laid on the ground, and the fleshy roots have been formed and are gradually entering the fleshy root expansion stage. In the middle stage of growth, in order to expand the fleshy roots in the later stage, it is necessary to do a good job in three aspects.

1. Prevention and control of pests and diseases. The insect pests of radish are mainly powdery mildew, aphids, moths, etc., and the diseases are mainly black rot, virus diseases, etc. In plots with frequent diseases, several injections of the drug often have no effect, so it is recommended to inject the drug in advance during the sit-down period.

One injection of medicine on a sit-in device works well. At a later stage, a lot of effort will be saved when preventing pests and diseases, and the quality of the radish will not be affected. Specific drugs can be selected according to the type of pest and disease occurrence.

2. Prevent cracks. Cracks in radishes are also a common problem and can reduce commerciality. The swelling of the fleshy roots of radish requires more nitrogen and potassium, as well as a certain amount of boron and calcium, and the soil has less nutrients or less drought, and the roots will crack if they are not absorbed.

In addition to fertilizing the soles of the feet, it is best to chase fertilizer once during the rosette period. It is mainly potash fertilizer, and it is better to use it with a small amount of nitrogen fertilizer.

Potassium dihydrogen phosphate, boron, and calcium chelated are sprayed on the leaves. This should be done during the sitting-up period to promote the growth of fleshy roots in the later stages. 3, Wang Zhuang.

After the radish enters the soft sitting stage, the leaves can produce nutrients that provide the growth of fleshy roots. At the beginning of meditation, it is necessary to squat appropriately to reduce the growth of lateral roots, prevent the growth of upper leaves, take root, and increase the single weight of the radish. The crouching saplings are mainly used to regulate the water, and the number of watering should be reduced and the amount of watering should be small.

After the squatting saplings are finished, they should also pour some small water to prevent the water from splitting unevenly. The crouching time should also be determined according to the growth trend of the radish itself. The radish itself has a weak growth momentum and does not have to squat anymore.

When planting radish, it is necessary to pay attention to the management skills of the rosette, lay the foundation for the expansion of soilless roots, and plant radishes with high quality and high yield.

In the north, it can lay eggs on autumn cabbage for overwintering; In the south, it can be parthenogenetic and reproduce continuously throughout the year. In March and April of the following spring, the eggs hatch into a dry mother, and after breeding on the overwintering host for several generations, they produce winged aphids, which are transferred to other vegetables and expand into damage. In late autumn, some of them produce sexual aphids and mate to lay eggs for overwintering.

In the Yangtze River Basin, the peak occurs in spring and autumn every year. Radish aphid has a wide range of adaptation, and at lower temperatures, radish aphids develop faster. There are more weeds in the field, and it occurs severely in dry years.

Choose resistant varieties of diseases and insects. A large area of radish planting is far away from the cruciferous vegetable field, leaving the planting field, paying attention to cleaning the garden, weeding frequently, and combining cultivating the old leaves and yellow leaves. Use silver reflective plastic film or silver-gray insect net to avoid aphids, and you can also use yellow plates to attract aphids.

When selecting pesticides for prevention and control, it is necessary to choose high-efficiency, low-toxicity and low-residue, insecticidal and low-toxicity pesticides. In the early stage of growth, it can be sprayed on the foliar surface 1:50 and irrigated with the roots 1:

500 diluted solution can kill aphids and can effectively control other diseases that occur in radish. The combination of chemical control and agricultural control has a good comprehensive control effect. Cure aphid disease.

Use green bag fertilizer (poisoning non-toxic insecticidal nutrient solution).

In the Yangtze River Basin, the peak occurs in spring and autumn every year. Radish aphid has a wide range of adaptation, and at lower temperatures, radish aphids develop faster. There are more weeds in the field, and it occurs severely in dry years.

In the middle of radish growth, pay attention to check the leaves and growth points, and find that there are radish aphids adsorbed on the leaves and growth points, it is necessary to spray 2-3 times 1000 times 25% imidacloprid aqueous solution, or 800 times 10% acetamiprid aqueous solution, or 1500 times 25% pymetrozine aqueous solution, or 1500 times 20% thiamethoxam aqueous solution, or 1000 times cypermethrin aqueous solution for control, spray once every 10-15 days, evenly spray all leaves, and it is advisable to start with water droplets dripping down. In addition, in the middle and late stages of the growth of the left-seeded radish, it is necessary to pay attention to watering and moisturizing to prevent the leaves from wilting caused by the lack of water of the plant, because the left-seeded radish will be more seriously damaged by radish aphids when the weather is dry.

Select resistant varieties. Large-scale cultivation of radishes should be kept away from cruciferous vegetable plots and leave land. Pay attention to cleaning the countryside, weeding frequently, and combining cultivating old leaves and yellow leaves.

Silver reflective plastic film or silver-gray insect net can be used to avoid aphids, and yellow plates can also be used to attract aphids. Control with aphids, natural enemies, parasitic wasps and aphids. Select pesticides with low toxicity and systemic and contact killing effects.

Spray 40% chrysanthemum emulsifiable concentrate or 40% chrysanthemum emulsifiable concentrate 200 3000 times, 21% synergistic cyanamide emulsifiable concentrate 3000 4000 times, 25% peiqingling 1000 1500 times, pay attention to the heart spray leaf and leaf back.

Agricultural control is an economical and effective measure to prevent and control aphids from harming vegetable seedlings and spreading viral diseases by selecting high-yield and high-quality varieties that are resistant to insects and viruses and raising seedlings in the net room. Cruciferous vegetables can be planted less or no to reduce or cut off the aphids and toxic sources of autumn vegetables. After the vegetables are harvested, the leaves of the residual plants should be treated in time; Clean the garden to kill insects before planting in the reserve; After planting, it should be isolated to prevent aphids from migrating and multiplying.

Growing corn in the open field and using corn as a barrier to prevent the migration and reproduction of winged aphids can reduce and delay the occurrence of viral diseases.

According to the negative tendency of aphids to silver-gray and the positive tendency to yellow, silver-gray plastic film is used to avoid aphids and prevent diseases, and yellow plates are used to trap and kill winged aphids. Protection and utilization of natural enemies in vegetable plots, many natural enemies have a significant inhibitory effect on aphids. When spraying pesticides, pesticides with less killing power against natural enemies should be selected, so that the number of natural enemies in the field should be kept at more than 1% of the total number of aphids.

In the early stage of aphids, the reserve releases aphid cocoon bees, which has a certain control effect. Chemical control, 2% Green Star EC 750 1400ml, avermectin EC, 5% ARIK EC, 5% cypermethrin EC, deltamethrin EC, 25% Actai EC 375ml, Neem WP 500 250g, 10% imidacloprid can be used per hectare, and laundry detergent or other dispersants can be added according to the water consumption to dilute the drug to improve the efficacy.

First of all, it is necessary to choose the right soil and the right temperature, and it is necessary to water regularly and fixedly, and it is necessary to spray some pesticides, and then it is necessary to set up the corresponding insecticide arrangement, and it is necessary to remove weeds in time.

You can increase the light appropriately, these insects are phototaxis, and you can spray some pesticides, and you can also weed frequently, so that it does not have room to grow.

Radish aphid winged female aphid: cephalothorax black, compound eyes russet, frontal nodules insignificant, abdomen yellow-green to green, black spots on both sides of the anterior segments of the abdominal canal, and sometimes a sparse white wax powder on the body. The abdominal canal is dark green and constricted at the apex.

Wingless female aphid: yellow-green with a slight white wax powder on the whole body, and faintly black horizontal markings on each segment of the chest. <>

Radish aphids occur in 10-20 generations a year in the north, and can reproduce all year round in greenhouses. In the absence of cruciferous vegetable growth in summer, parasitism on cruciferous weeds. The radish seedling stage is the period when aphids occur in large numbers, so that the damaged radish plants cannot grow normally.

Aphids can also transmit viral diseases, which can make the skin of radishes rough and affect quality and yield. In addition to harming spring radish in spring and summer, aphids also harm the leaves of seed collection plants, affecting the normal sprouting, flowering and pod-setting of plants on the back of vegetable leaves or the tender shoots and young leaves of the seed plants, resulting in shortening and bending of the internodes, and the deformity and shrinkage of young leaves downward, making the plants dwarf, affecting the core or balling, resulting in reduced yield. The left-behind vegetables are damaged and cannot sprout, flower, and set seeds normally.

At the same time, the transmission of viral diseases causes far more harm than the aphid itself <>

The control methods of radish aphid are as follows:

1.After the harvest of cultivation and control vegetables, clean up the residual plants and leaves in the field in time and eradicate weeds. According to the local radish aphid occurrence. Reasonably determine the planting period to avoid the peak of aphid migration and virus transmission.

2.There are many pesticides for the control of radish aphids, and insecticides that are safe for natural enemies should be selected first to protect natural enemies. Radish aphids are mostly gathered in the heart leaf or the back of the leaf, and the spraying is thoughtful, and the agent with both contact killing, internal absorption and fumigation is selected.

50% anti-aphid wettable powder 2000-3000 times liquid spray, good effect, no killing of natural enemies. When the temperature is higher than 20, the anti-aphid fumigation effect is obvious, and the insecticidal effect is better. You can also choose 2000-3000 times of Uranus EC, or 3000 times of 20% fenvalerate EC, or 5000 times of 21% kill (synergistic cyanima) EC, or 2500 times of 10% imidacloprid wettable powder, or 8000-10000 times of 70% Emele water dispersible granules.

It will affect the yield of radish, as well as the growth rate of carrots, and will cause some damage to seedlings, the most important thing is that it is likely to cause some damage to the roots and leaves of seedlings in this process, which must be cleaned up in time.

Reproduction may be terminated. It affects quality, it affects yield, and it spreads viruses and it can spread. It can harm the leaves of the plant. It also affects the normal amount.

Radish aphid belongs to the family Homoptera, and it is infested by the aggregation of adult aphids and aphids, and it can also cause deformities and shrinkage of young leaves and poor growth.

Moreover, after the plant is damaged, it cannot sprout, bloom and bear fruit normally.

Radish aphids can also transmit viral diseases, which can harm all turnips.

It will cause damage to the leaves at the seedling stage, curl, yellow, slow growth, and death in severe cases.

Viral disease: spray 1000 times of phytoling emulsion once every 7-10 days. Downy mildew:

Radish seedlings should be reasonably irrigated and fertilized, and azoxystrobin should be used for prevention and control after the onset of the disease. Brassica insect: spray with 2000 times of 5% anti-Taibao EC.

Vegetable borer: Spray 2500 times kung fu emulsifiable concentrate for radish.

1. Viral diseases

Radish seedlings are susceptible to viral diseases, the heart leaves have obvious clear pulse disease in the early stage of susceptibility, and gradually form light mosaic leaf mottling, the pathogen is mainly spread by aphids, whiteflies, whiteflies and other pests, after the disease is found, spray 1000 times of plant disease emulsion once every 7-10 days.

2. Downy mildew

Radish in the seedling stage suffered from downy mildew infection, the leaves will die from bottom to top, but generally will not infringe on the leaf center, the seedling stage should be reasonable irrigation and fertilization, to avoid the appearance of high humidity, high fertilizer environment, after the onset of the disease with 80% mancozeb or azoxystrobin for the plant evenly sprayed.

3. Cabbage worms

The cabbage worm adults on the radish will generally lay eggs on the back of the leaves, like vertical wheat grains, injurious to the cabbage leaves after hatching, after the plant produces cabbage worms, spray with 5% anti-Taibao EC 2000 times liquid in time, and the spraying time is better on a cloudy day when the temperature is higher than 15 degrees.

4. Vegetable borer

Vegetable borer adults mainly lay eggs on the young leaves such as the heart leaves of radish seedlings, and when the plant is seriously damaged and die, it is necessary to spray the pests during the incubation period of the eggs and the first sight of the heart leaf damage, and the agent is selected 2500 times the liquid of kung fu emulsifiable concentrate or 1000 times of 50% phosphine emulsifiable concentrate.