When planting sweet potatoes, how can you control grubs?

In the sweet potato root expansion period, the roots can be irrigated with 20 times the tobacco leaf leaching solution, 3500 kg per mu, and the roots can be irrigated about 3 times in a row. This liquid is pure plant and will not cause any pesticide damage to sweet potatoes, so you can use it with confidence. It can also be applied in the sweet potato planting stage, potato tuber expansion stage or larval peak stage after the spore infects the grub larvae, making it lethal, and there is still a certain control effect after three years of fungus soil application.

Grubs are more sensitive to light, and can use flashlights at night, or install some insecticidal lamps and other facilities to eliminate them before the beetles lay eggs. Daily attention to detect the grub in the sweet potato field, when the sprouts appear, timely manual capture, you can also put some poultry or introduce natural enemies to peck, but you need to pay attention to the time and quantity, so as not to cause damage to the sweet potato stems and leaves. In late June, in the summer high temperature and high humidity environment, it is more suitable for the growth and reproduction of grubs, which requires us to spend more time and energy, especially at night to physically control pests and reduce harm.

After the outbreak of grub insect pest in sweet potato, the most effective and direct method is to spray pesticides, which can be sprayed with about 50% octanol emulsifiable concentrate 800 times, about 40% poison silk or 800 times 50% malasulfate emulsifiable concentrate, etc., sprayed once a week or so, and the impact of grubs will be reduced for about a month, especially in the adult outbreak stage. Sometimes after transplanting sweet potato seedlings, prevention will also be carried out in advance, such as mixing some new sulfuric acid emulsifiable concentrate with water and sprinkling it on the field where sweet potatoes are planted, or directly mixing some insecticides with water and acting on the field to prevent grubs in advance.

One is to spray pesticides or insecticides to reduce the growth of grubs, and at the same time, it can also be well prevented in advance. Second, in the daily management of water and fertilizer, appropriate use of fertilizers containing phosphorus or ammonia to strengthen the insect resistance of sweet potatoes.

Because the grub grows in the underground soil, the adult beetle lays eggs in the soil, hatches the larvae, the larvae are relatively fat, white, and have brown patches on the head, hiding underground during the day, and coming out at night to move, biting the rhizomes of edible sweet potato seedlings. This year's sweet potato ** compared with previous years has decreased a lot, on the one hand, the sweet potato planting area has expanded, more importantly, on the other hand, the quality and appearance of sweet potatoes are very bad, grubs like to bite sweet potato seedlings and roots, is one of the biggest pests that harm the yield and quality of sweet potatoes, sweet potato seedlings are bitten by grubs will cause lack of seedlings, broken ridges, dead seedlings, and the potato pieces eaten by grubs are susceptible to infection.

Sweet potato is a crop that is more taboo with stubble, and stubble will have a higher chance of being infected with soil-borne diseases. We need to use scientific management methods to prevent and control it, and then Tianyi combines some experience of growing sweet potatoes at home, starting from the following five aspects, to see how to prevent and control the harm of grubs to sweet potatoes.

Experienced people in the countryside know that when the winter is warm, there will be more pests in the spring of the following year, and the colder the winter, the fewer pests there will be in the spring of the following year. It means that some eggs can be frozen to death in the cold winter. Therefore, spring sweet potatoes must be deeply ploughed and turned over the soil for winter, which can effectively reduce the occurrence of pests.

However, many farmer friends will say that I use more than this, but the effect is very poor, and there are still many insect eyes in the sweet potatoes harvested! Here's the secret, the reason for which manufacturer's product to use. This phenomenon is the result of a typical underground pest damage of sweet potatoes.

The source of underground pests of sweet potatoes is mainly caused by the use of organic fertilizer that has not been thoroughly decomposed and matured through high-temperature fermentation, followed by the emergence of adult insects into the soil in the natural environment to reproduce and soil-borne pests. I have been growing sweet potatoes for many years, and I have summarized some practices to prevent grubs, and I will share them with you below. The pests that bite sweet potatoes are mainly grubs, this guy has a sharp stomach and mouth, powerful teeth, and is particularly tossed, and ordinary drugs can't poison it.

When planting sweet potatoes, avoid heavy cropping, and after harvesting sweet potatoes, remove the vine residues and weeds of sweet potatoes in a centralized manner, and take them out of the field for other treatment. Before planting sweet potatoes and overwintering, the soil in the field is carefully raked to reduce the number of seedlings in the soil.

1. Physical control: Using the characteristics of adult phototaxis and chemotaxis, black lights and sexual attractants can be used to trap and kill adult grubs (beetles). Mid-June to late July is the peak period for adult worms, which is the peak season for sweet potato growth, and black lights can be installed in sweet potato fields to trap and kill adult insects.

2. Agricultural prevention and control: mainly combined with farming measures to control grubs. Potato-wheat rotation is often practiced in the northern potato area, which can be dried in the soil after the wheat harvest in early June, and the chickens can be artificially killed or raised to peck at the larvae.

In October, the summer potatoes are harvested at the same time to complete the deep ploughing of the land, which destroys the living environment of the grub in the soil, and the grub can use irrigation to eliminate the larvae by using the characteristics of the grub to be afraid of flooding.

3. Biological control: At present, the most widely used and most effective is the use of Beauveria bassiana, Metarhizium aeruginosa and other fungal preparations to control grubs, especially Beauveria bassiana in the sweet potato field to control grubs is very successful. After the application of Beauveria bassiana at the planting stage, the tuber swelling stage or the peak larval stage, the spores infected the grub larvae and made them lethal, and the fungus soil still had a certain control effect after three years of application.

This method has the advantages of low resistance to pesticides, less residue and high pathogenicity, and has broad application prospects.

4. Chemical control: This method has the advantages of fast effect, good control effect, economy and practicality, and is still the main means of controlling grubs on sweet potatoes in China.

First, the best time to control grubs, around mid to early July every year is the best time to control grubs, this time is the time when its adults are in full bloom, generally from mid-June. The severity is related to soil temperature and humidity. Normally, the soil temperature is most active when it reaches 13-18, and its activity will intensify when the soil moisture is high.

2. What medicine is good for killing grubs?

1. When killing grubs, you can use 50% octathion emulsifiable concentrate, you can spray the soil mold with 10 times the water to wash, mix the soil with this agent, and then sprinkle the poisonous soil in the ditch, so that the pests can be poisoned. It is also possible to use 3% vepardan, 3% isosulfonate particles, etc.

2. In addition to mixing soil with medicine, it can also be used to mix seeds, you can choose 50% parathion, 50% phosphine, and water, and the ratio of seeds is 1:30:400, so that you can avoid being damaged after planting, and at the same time you can also treat some other pests.

3. Other control measures.

Agricultural control methods can also be used in addition to the control of drugs. In the process of farming, the organic fertilizer of unrotted Hu Bi is not applied, and the soil is pressed in time. In areas where pests are severe, the overwintering larvae are turned over to the ground to dry in autumn and winter, freezing to death or being killed by natural predators.

In addition, physical control methods can be used to set up black light traps to reduce the occurrence of insect pests.

The first point is to find out the whole regularity of it, that is, it will come out once every half a month, and the third point is that the soil should be renovated and sprayed with pesticides regularly.

the implementation of water and drought crop rotation; Timely irrigation during the growth of maize; Do not apply uncooked organic fertilizer; intensive cultivation, timely suppression of the soil, cleaning of weeds in the field; Large-scale spring and autumn ploughing, and plough picking up insects. In areas where the occurrence is severe, the overwintering larvae can be turned to the surface in autumn and winter to dry up, freeze to death or be preyed on by natural enemies, and the mechanical killing and control effect is obvious; At the same time, the use of uncooked organic fertilizers should be avoided to prevent the attraction of adult worms to lay eggs. The adult worms of the grub lay eggs 10 to 15 days after mating, lay in the soft and moist soil, and water the ground more, and each female can lay about 100 eggs.

The number of annual generations of grubs varies from species to species and from place to place. This is an insect with a long life cycle, generally one generation, or one generation in 2 or 3 years, and one generation in 5 or 6 years for the elderly. For example, the great blackgill beetle has one generation in two years, the dark gill beetle and the bronze green beetle have one generation a year, the small cloud-spotted gill beetle has one generation in four years in Qinghai, and the large chestnut gill beetle needs one generation in 5 or 6 years in Ganzi area of Sichuan.

The grub has a total of 3 instars, and the instar period is shorter, and the 3rd instar stage is longer.

1. Prevention and control methods of underground pests.

The control methods of underground pests can be divided into two types: physical control and chemical control. Physical control is now in place, especially for soil-borne pests. As we all know, the eggs of pests can only be safely wintered by hiding in the soil, so they only need to be deeply ploughed and turned deep after winter to destroy the hiding conditions of pests, and the eggs can be frozen to death.

That's why the colder the winter and the cooler the temperature, the fewer pests there will be in the spring of the following year.

Organic fertilizer is fully decomposed to eliminate pests**. Farmers must be fully decomposed according to the requirements when decomposing organic manure, and only after high temperature treatment can the eggs and germs in the manure be killed together, so as to reduce the pests and diseases caused by organic fertilizer. Organic fertilizer can also cause phenomenon such as seedling burning if it is not fully decomposed, which is not conducive to the growth of crops.

2. Chemical control methods for underground pests of sweet potatoes.

Chemical control methods are mainly divided into soil disinfection, seed dressing, root irrigation and other methods. Soil disinfection is mainly combined with deep soil turning, sprinkled with phosphine particles mixed evenly with the soil, and combined with pre-winter irrigation. Or when applying organic fertilizer, it is mixed with phosphine and other agents for disinfection.

Irrigating the roots is a way to kill insects. In the sweet potato root expansion stage, 30 times of superphosphate and plant ash were dissolved in water, and the supernatant was taken for root irrigation after full mixing, and the roots were irrigated once every half month. You can also irrigate the roots with 20 times the tobacco leaf leaching solution, 3500 kg per mu, and irrigate the roots about 3 times in a row.

These two liquids are pure plant and fertilizer type, and will not cause any pesticide damage to sweet potatoes, so they can be used with confidence.

3. In addition to the above methods, foliar spraying can also be used.

That is, spray sweet potato leaves with fertile leaf amino acid foliar fertilizer solution, spray once every 10 days, and spray about 3 times in a row.

The most important thing for the prevention and control of underground pests of sweet potatoes is to do a good job in crop rotation and disinfection of farm fertilizer. In addition, the main edible part of sweet potatoes is the tuber, so it is not recommended to irrigate the roots with chemical pesticides to kill insects, minimize the use of pesticides, and reduce pesticide residues.

The key is to plant sweet potatoes, taro, potatoes, and prevent and control underground pests such as early in the morning, the best way is to grow the law in the ground, and this sweet potato is to prevent pests from using some pesticides, or other should be possible.