Recently, high temperature and high humidity, high incidence of cotton, corn, vegetables and other crops, the application of a vitamin salt and avermectin has reached its peak. Both avidin and avermectin are common agents on the market today. Everyone knows that they are biological agents and have a relationship, but do you know how to choose different control objects?
Avermectin is an effective agent that can be used in almost all crops to control almost all pests, and it is a similar agent with a significantly higher activity than avermectin. It can be said that the vitamin A salt is developed on the basis of avermectin and is a reinforced form of avermectin, which has a similar insecticidal spectrum.
The activity of methicillin is much higher than that of avermectin. The insecticidal activity is 1-3 orders of magnitude higher than that of avermectin. It is extremely active against the larvae of lepidopteran and many other pests and mites. It has a stomach poisoning effect and a contact killing effect, and also has a good insecticidal effect at a very low dose. However, a lot of data show that the insecticidal ability of this series of products (especially stomach virulence) has increased with the increase of temperature, but the temperature of methicillin and avermectin increases and the virulence increases. The magnitude is inconsistent.
At 16 ° C, the same content of methicillin is 2-3 times more active than avermectin; when the temperature is raised from 16 ° C to 22 ° C, the virulence of avermectin is increased by about 6 times, and The virulence of the salt is only increased by 2-3 times, so the insecticidal effect of using the same content of avermectin and carbaryl at 16 ° C to 22 ° C is almost equivalent.
At present, the registration data shows that the amount of active ingredients in the avermectin registration is generally higher than that of the vitamin A. This results in the use of avermectin in the actual use is higher than the salt of the vitamin A, so the effect of avermectin is better than that of the methyl salt at about 22 °C.
When the temperature rises above 25 °C, the virulence of the vitamin A salt will increase greatly, and even increase it to more than 1000 times, while the virulence of avermectin can only increase several times to ten times. The insecticidal effect of the salt of the vitamin A is obviously better than that of the avermectin. At this time, the advantage of the salt of the vitamin A is really exerted. Because different pests have different temperature of insect pests due to their own habits, the correct choice of pests should be based on the pest habits.
The occurrence of the leafhopper is generally above 28-30 °C, so the effect of preventing the leafhopper should be the one-dimensional salt is much better than the avermectin; the occurrence of the Spodoptera litura is usually in the high temperature and drought, that is, 7 per year. During the months of October-October (summer), the effect of carbaryl salt is better than avermectin; the optimum temperature of Plutella xylostella is just about 22 °C, which means that Plutella xylostella will occur at this temperature, so It will occur that the prevention of P. xylostella is not as good as that of avermectin.
Detailed knowledge of avidin and avermectin
First, a vitamin salt
(1) Physical and chemical properties:
Colorless transparent liquid, slightly ammonia smell, miscible with water, miscible in ethanol, most organic solvents, flash point 10 ° C, melting point -55.1 ° C boiling point 121-122 ° C, relative density 0.78 (water = 1), stable .
It is a new type of high-efficiency semi-synthetic antibiotic insecticide synthesized from the fermentation product avermectin B1. It has the characteristics of ultra-efficient, low-toxicity (nearly non-toxic), no residue, no pollution and other biological pesticides .
Compared with avermectin, the insecticidal activity is increased by 1-3 orders of magnitude, and the activity of larvae and many other pests and mites of lepidopteran insects is extremely high, both stomach poisoning and contact killing, at very low The dosage (0.084-2g/ha) has a good effect, and it does not harm the beneficial insects in the process of controlling pests, which is beneficial to the comprehensive control of pests, and further expands the insecticidal spectrum and reduces the toxicity to humans and animals.
(2) Applicable crops:
A vitamin salt is highly safe for all crops at protected sites or 10 times the recommended dosage, and has been used in many food crops and cash crops in Western countries.
Consider it is a rare green pesticide. China should first use it on tobacco, tea, cotton and other cash crops and all vegetable crops to control pests.
(3) Mechanism of action:
A vitamin salt can enhance the action of neurotransmitters such as glutamate and gamma-aminobutyric acid (GABA), thereby causing a large amount of chloride ions to enter nerve cells, causing loss of cell function, disturbing nerve conduction, and larvae stop eating immediately after contact. Reversal of paralysis reached the highest mortality rate within 3-4 days.
Because it is tightly combined with soil, does not leaching, does not accumulate in the environment, can be transferred by Translaminar movement, is easily absorbed by the crop and penetrates into the epidermis, so that the crop has long-term residual effect, and appears second in more than 10 days. The killing rate of insecticides is high, and it is rarely affected by environmental factors such as wind and rain.
(4) Prevention and control of pests:
A vitamin salt has many activities unmatched by other pesticides, especially for Lepidoptera, Diptera, and ultra-efficient, such as the red-striped moth, the larvae, the cotton bollworm, the tobacco hawk moth, the diamondback moth, the beet Noctuid moth, Dryland moth, Rhododendron chinensis, Brassica chinensis, Cabbage butterfly, Cabbage, Cabbage, Tomato hawk moth, Potato beetle, Mexican ladybug, etc.
1, beet armyworm
The activity of avidin on the larvae of Spodoptera exigua is 13 times that of avermectin (3rd instar larvae, the same below), 53 times that of cypermethrin, 57 times that of hexaflumuron, and 119 times that of chlorpyrifos. The gastric toxicity of Awei salt to Beet armyworm is 1500 times higher than that of avermectin.
2, cotton bollworm
The contact toxicity of avidin to Heliothis armigera is 146.7 times that of beta-cypermethrin and 210.7 times that of methyl parathion. The gastric toxicity of the methyl sulphate to cotton bollworm is 4,721 times that of methyl parathion. 0.2% Awei salt oil diluted 4000 times to prevent 4th instar cotton bollworm, the mortality rate was 98.5%, significantly higher than 50% methyl parathion EC 2000 times (30.5%), 0.2% avermectin 1000 times (45.5%) The control effect.
The use of 1% can be used to control cotton bollworm, the duration of action can be as long as 10d, and the control effect is higher than that of octyl chloride emulsifiable concentrate under the condition of 1% methyl salt EC 30 ml, 60 ml, 90 ml. No adverse effects on cotton growth.
3. Plutella xylostella
Plutella xylostella, which has been resistant to organophosphorus, carbamate, organochlorine, pyrethroid, and chitin inhibitors, has a good control effect on it. However, Plutella xylostella, which has been resistant to avermectin, should be used with caution.
The Plutella xylostella was diluted 3000 times with 0.5% KM salt oil, and the insecticidal effect on 7d was 98.4%. Using 1.0% Awei salt oil diluted 8000 times to control Plutella xylostella, 6d insecticidal effect was 86.51%, diluted 6000 times to control Plutella xylostella, 6d insecticidal effect was 91.45%. The 4.50% beta-cypermethrin emulsion diluted 1667 times against Plutella xylostella was only 69.04%
4, vegetable pests
The larvae of the cabbage larvae (Pieris rapae) was diluted 8000 times with 1.0% gamma salt oil. The insecticidal effect was 86.03% on 8 days, and the Phytophthora sinensis was diluted 6,000 times. The insecticidal effect on 8 days was 96.85%.
1% of the vitamin A can be diluted 6,000 times for the control of Pieris rapae, and the effect is equivalent to the insecticidal effect of 4.56% dilution of 4.5% beta-cypermethrin.
5, Awei salt has high activity on leaf-feeding pest larvae and cotton red leaves and alfalfa, but the effect on aphids is slightly worse.
According to foreign reports, 1% of the vitamin A is mainly used to control the following vegetable pests: Cabbage, wild worm, Spodoptera, Plutella xylostella, cabbage, thin-winged wild pheasant, cabbage caterpillar, tobacco budworm, soybean Spodoptera litura, Brassica chinensis and Liriomyza. The general dosage is 8.4-16.8 g (ai)/hm2, and the duration of effect is more than 10d.
According to foreign special reports
The effect of avidin on the southern gray-winged moth is 1166 times that of avermectin, 43 times that of avermectin, and 105 times that of avermectin, and the contact activity. It is 4 times more avermectin, but it is slower to touch. The contact test was 4d, and the effect on oriental armyworm was 168 times that of avermectin.
(5) A vitamin salt has been clinically discovered in use, and it cannot be used continuously during the growth period of the crop. It is best to use it after the first stage of the insect stage, and use the other pesticide interval during the second stage of the insect stage!
(6) Notes:
1. Take protective measures when applying the medicine, wear a mask, etc.
2, high toxicity to fish, should avoid pollution of water sources and ponds.
3. Toxic to bees, do not apply during flowering.
2. Avermectin
(1) Physical and chemical properties:
The original powder is white or yellow crystal (including B1a ≥ 90%), vapor pressure <200nPa, melting point 150-155 ° C, solubility at 21 ° C in water 7.8 μg / liter, acetone in 100, toluene 350, isopropanol 70, chloroform 25 (g / L) is not easy to decompose at room temperature.
There is no decomposition in the solution at 25 ° C, pH 5-9. The commonly used pesticide is called avermectin ointment, which is an accessory of avermectin refined powder. It is a xylene-soluble emulsifiable concentrate with a content of 3-7%.
(2) Mode of action and characteristics:
Touch, stomach poison, strong penetration. It is a macrolide disaccharide compound. It is a natural product isolated from soil microorganisms. It has a contact and stomach toxicity effect on insects and acarids, and has a weak fumigation effect, and has no systemic action.
However, it has a strong osmotic effect on the leaves, which can kill the pests under the epidermis and has a long residual effect. It does not kill eggs.
Its mechanism of action differs from that of general insecticides in that it interferes with neurophysiological activities and stimulates the release of r-aminobutyric acid, while r-aminobutyric acid inhibits the nerve conduction of arthropods, such as mites, mites and insects. The larvae appear paralyzed after contact with the agent, inactive and do not feed, and die after 2-4 days.
It does not cause rapid dehydration of insects, so its lethal effect is slower. However, although there is a direct killing effect on predatory and parasitic natural enemies, the damage to beneficial insects is small due to the small residual surface of the plants. It has obvious effects on root-knot nematodes.
(3) Symptoms of poisoning:
Early symptoms are dilated pupils, dysfunctional movements, and muscle tremors. It generally causes the patient to be highly comatose.
First-aid treatment: Oral: Immediately induce vomiting and give patients vomit syrup or ephedrine, but do not induce vomiting or filling anything in a comatose patient. Avoid using drugs that enhance gamma-aminobutyric acid activity such as barbital, valproic acid, etc. during rescue.
(4) Notes:
1. Take protective measures when applying the medicine, wear a mask, etc.
2, high toxicity to fish, should avoid pollution of water sources and ponds.
3, the silkworm is highly toxic, and the mulberry leaves have obvious poisonous silkworm killing effect 40 days after spraying.
4. Toxic to bees, do not apply during flowering.
5. The last application is 20 days from the harvest period.
(5) Toxicity:
The original drug is highly toxic and degrades rapidly in the soil.
(6) dosage form:
0.5%, 0.6%, 1.0%, 1.8%, 2%, 3.2%, 5% emulsifiable concentrate, 0.15%, 0.2% hypertonic, 1%, 1.8% wettable powder, 0.5% hypertonic microemulsion, and the like.
(7) How to use:
1. Control Plutella xylostella and Pieris rapae, use 1000-1500 times 2% avermectin EC + 1000 times 1% KM salt in the young larva stage, which can effectively control the damage of Plutella xylostella 14 days after the drug The effect is still 90-95%, and the control effect against cabbage caterpillar can reach more than 95%.
2. Control pests such as the golden moth, the leaf miner, the leaf miner, the Liriomyza huidobrensis and the vegetable whitefly, and use 3000-5000 times 1.8% avermectin EC +1000 in the egg hatching period and larval stage. Double-chlorine spray, the control effect is still more than 90% after 7-10 days.
3, prevention and control of beet armyworm, with 1000 times 1.8% avermectin EC (Aino 3), 7-10 days after the drug control effect is still more than 90%.
4. Control leafhoppers, alfalfa, sassafras and various resistant mites of fruit trees, vegetables, food and other crops, using 4000-6000 times 1.8% avermectin emulsifiable spray.
5, prevention and control of vegetable root-knot nematode disease, according to the use of 500 ml of Ainuoqing 3 per acre, the effect of 80-90.
(8) Notes:
1. The drug has no systemic action. When spraying, it should be sprayed evenly and carefully.
2, can not be mixed with alkaline pesticides.
3. Do not spray at noon in summer.
4. Store this product away from heat and fire.
5. Stop applying the drug 20 days before harvest.
6. Avoid contact with the skin or splashing into the eyes. If this happens, rinse immediately with clean water and consult a doctor.
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