How do vegetables grow aphids? What are the prevention and control methods? What kind of pesticide should I use?

With the development of vegetable planting industry, the harm of vegetable aphids is becoming more and more prominent. So, what about vegetable aphids? What are the control methods for vegetable aphids? What pesticides are good? Today's editor will lead you to understand:

Vegetable aphid damage

There are many kinds of vegetable aphids, including radish aphid, cabbage aphid, tobacco aphid, peach aphid, melon aphid, bean aphid, etc., among which radish aphid, cabbage aphid, tobacco aphid damage vegetables mainly. Aphids occur about 20 generations a year. Aphids often gather on the back of vegetable leaves in groups, mainly sucking vegetable juice, causing serious water loss and malnutrition, which makes them grow slowly and stagnate when they are seriously injured. After the leaves are injured, they show curling, yellowing and deformation; tender stems and pedicels are deformed after being injured, affecting seed setting. Apart from direct damage to vegetables, aphids excrete a large amount of honeydew, which not only affects the yield but also reduces the quality of vegetables. In addition, aphids are the main disseminators of various virus diseases, which can transmit viruses from infected vegetables to healthy plants in a short time, and the losses caused by virus diseases transmitted by aphids are no less than those caused by aphids.

In winter, vegetable aphids continue to damage in protected areas and greenhouses, overwinter in eggs or parthenogenes in (Chinese cabbage) in open vegetable areas, and some overwinter on spinach. From March to April of the next year, the eggs hatch, and after several generations of parasitic reproduction, winged aphids are produced, and then move to cruciferous vegetables, and then gradually spread to Solanaceae vegetables or other vegetables to cause damage, forming a spring damage peak. In summer, due to more rain, high temperature and many natural enemies, it is not conducive to the occurrence of aphids, and the damage is relatively light; in late August, with the temperature gradually decreasing, the rain decreases, which is suitable for the reproduction of aphids, forming the peak of autumn damage. Therefore, autumn is an important period for the control of vegetable aphids. In October, the winged aphids migrate to overwinter, damage the host and reproduce, and produce sexual aphids to mate and lay eggs for overwinter.

Causes of Recurrence of Vegetable Aphids

1. The host range is expanded and the damage period is long.

In recent years, with the increase of vegetable varieties, the area of protected land has expanded. The number of vegetable varieties increased from more than ten to more than 30, which provided sufficient food source and overwintering place for aphids. In the past, aphids overwintered for several months in winter, but with the development of protected areas, aphids no longer overwintered but continued to harm, and the occurrence base of aphids in the next year was large. In spring and autumn, all vegetable varieties were not spared; in addition, excessive application of nitrogen fertilizer and excessive shading of vegetable fields also caused serious aphid occurrence.

2. Large food intake and fast reproduction rate

Both adult and nymph aphids suck the sap of host plants by sucking mouthparts. According to the determination, the weight ingested by an adult aphid in 24 hours is 8 times of its own weight. Aphid fecundity is very strong, each female aphid life can give birth to about 70 aphids, when the field food is abundant, wingless aphids large number, and cluster damage; when the field food shortage or environmental conditions are not appropriate, a large number of winged aphids will appear, and can spread to cause greater losses.

3. Strong drug resistance, difficult to prevent and control, large investment in labor

According to the investigation, the investment, investment and dosage of aphid control accounted for more than 50% of the whole vegetable pest control. Due to the large amount of drugs, prevention and treatment times, human and animal poisoning accidents also occur from time to time.

4. Poor control of natural enemies

Aphids are greatly affected by natural enemies, such as aphids, ladybugs, laceflies, aphids and other natural enemies in the field when the number is large, have a certain inhibitory effect on aphids. However, due to the blind application of vegetable farmers, see insects on the spray, the natural enemies of aphids kill large, so that aphids lose natural control.

5, the impact of temperature and humidity on the occurrence

From the observation in recent years, it is found that temperature and rainfall have great influence on aphid occurrence. The temperature of 20~25℃ is beneficial to aphid occurrence and harm, and the temperature exceeding 30℃ inhibits aphid occurrence. If the winter drought, high temperature, then the next spring heavy, summer high temperature, high humidity weather adverse to aphid occurrence. If autumn drought, autumn damage is serious.

Control methods of vegetable aphids

1. agricultural control

In the farming system, try to implement crop rotation and avoid continuous cropping. After the previous crop of vegetables is harvested, it is necessary to plough and dry the ridge in time to remove the impurities in the field to reduce the aphid source. Aphids like to eat carbohydrates. In the process of vegetable cultivation, more decomposed farm manure should be applied, and chemical fertilizer should be used as little as possible, especially not too much fertilizer at one time, so as to avoid excessive green and excessive growth of vegetable leaves. If the plant has a sudden increase in carbohydrates, aphids will explode in a short time.

2. Natural enemies control aphids

There are many kinds of natural enemies of aphids, mainly including ladybug, ladybug, grass clam, aphid fly and aphid fungus. Pay attention to protecting these beneficial natural enemies and make use of them, so as to eliminate a large number of aphids and control the population of aphids within the number that is not enough to cause large-scale damage. When there are not many aphids in the field and there are a certain number of natural enemies, do not apply pesticides to avoid harming natural enemies and destroying ecological balance. When the aphid damage reaches the control index, it is necessary to apply drugs on the affected parts of the plant, such as the growth point, tender leaves, young stems, leaf backs, etc., so as to fully protect natural enemies.

3. yellow plate aphid trap

The winged adult aphids have a strong tendency to yellow and orange. In production, yellow cardboard of 15 cm ×20 cm can be made, and a layer of No.10 engine oil or pesticides commonly used to control aphids can be coated on the cardboard. The yellow cardboard can be inserted or hung between the rows of vegetables and the top of vegetables. Oil yellow board lured aphids to replace in time, drug yellow board can make aphids touch medicine that is dead.

4. Silver gray film to avoid aphids

Aphids have strong avoidance of silver-gray, and can hang some silver-gray plastic strips in the field or cover vegetables with silver-gray plastic film.

5. urine-washing mixture

Urea, washing powder and clean water are prepared into urine washing mixture according to the ratio of 4:1:400, and evenly and carefully sprayed on both sides of leaves, spraying 60 kilograms of liquid medicine per mu for 2~3 times continuously. Spraying urine-washing mixture not only has good control effect on vegetable aphids, but also has the effect of foliar fertilization to promote growth. However, the urine washing mixture should be prepared now to prevent urea volatilization failure.

6. Plant aphid control

(1) Tobacco is ground into fine powder, and a small amount of lime powder is added for spraying;(2) Chili or wild Artemisia is soaked in water for one day and night, filtered and sprayed;(3) Castor leaves are crushed and sprayed, or soaked in water at a ratio of 1:2 for 10 minutes, filtered and sprayed;(4) Peach leaves are soaked in water for one day and night, and a small amount of quicklime is added, filtered and sprayed.

7. Plant aphid repelling

For example, the smell of leek volatiles has repellent effect on aphids, so planting leek with other vegetables can reduce the density of aphids and reduce the damage of aphids to vegetables.

8. Pig gall solution kills aphids

Adding proper amount of baking soda or washing powder to 10% pig bile solution and spraying it directly on vegetable plants damaged by aphids and cabbage worms can effectively kill pests. Diluted liquid can be maintained for 10 to 12 days without failure.

9. Lime powder kills aphids

Sprinkle lime powder on vegetable leaves with aphids, and aphids will soon be killed.