How to use pesticides scientifically? Master these usage techniques
In recent years, as people's living standards have continued to rise, the requirements for the quality of vegetables and fruits have also continued to increase. People want these vegetables and fruits to not only look good, be fresh and delicious, but also hope that the vegetables they eat are healthy and free of contamination, causing no harm to the human body. The demand for the latter is especially strong, and many people, when buying such products, specifically choose ones with slight insect damage, believing that such vegetables or fruits have not been sprayed with pesticides and will not harm the body when eaten. From this it can be seen that modern people are paying more and more attention to improving their quality of life. So how to use pesticides on the fruits and vegetables being grown, and how to use pesticides scientifically and reasonably, has become a issue of greater concern to modern growers. Let's take a specific look below: how to use pesticides scientifically.
1. Chlorothalonil: cannot be mixed with alkaline pesticides such as lime sulfur, for example propanil, Bordeaux mixture, lime sulfur mixture, etc.
2. Carbendazim: can be mixed with general fungicides, but when mixed with insecticides or acaricides it must be used immediately after mixing, and it is not suitable for mixing with alkaline agents.
3. 64% Sandofan: it is made from a mixed formulation of oxadixyl and mancozeb, has systemic conductivity and contact action, controls downy mildew and white rust, is stable on crops, is not likely to cause phytotoxicity, and various crops have high tolerance to Sandofan and will not suffer phytotoxicity. Sandofan mixed with agricultural streptomycin is prohibited during the cucumber seedling stage.
4. Oxadixyl: it has very high control efficacy against pathogens of the order Peronosporales, has protective and curative effects, and has a long residual period. When mixed with mancozeb, its control efficacy is higher than when mixed with folpet or copper preparations, such as 64% oxadixyl · mancozeb wettable powder (Sandofan).
5. Tomato gray leaf spot: for every 667 sq m, 200 g of 15% procymidone smoke fungicide (Sumilex plus chlorothalonil) can be used for fumigation treatment.
6. How to use pesticides to control tomato leaf mold: (1) Broad-spectrum fungicides: such as chlorothalonil (Daconil), iprodione, thiophanate-methyl, etc. The advantages of this type of agent are: broad disease-control spectrum, safety, low price, and good preventive effect. The disadvantage is: poor curative effect. Therefore, it should be used before disease onset, or used together with drugs that have outstanding curative effects. (2) Azole agents: such as myclobutanil, triflumizole, difenoconazole, etc. The advantages are significant curative effect, low dosage, strong systemic action, and long residual period. The disadvantage is: a large dosage will inhibit crop growth. If the number of consecutive applications exceeds three times, it is very likely to cause tomato leaves to become smaller, harder, more brittle, and black, so it should be used with caution, especially in winter low-temperature periods when it should be used even less, except for difenoconazole. When using this type of agent, it can be used together with some growth regulators, such as brassinolide, cytokinins, etc., to reduce its side effect of inhibiting tomato growth. (3) Antibiotic agents: such as kasugamycin, polyoxin, agricultural antibiotic 120, etc. The advantages of these agents are: safety, broad spectrum, strong systemic action, and outstanding preventive effect, but their curative effect is relatively poor. Based on the above characteristics of the agents, when using agents to control tomato leaf mold, the following medication should be used: when leaves have no disease spots or the incidence rate is below 5%, broad-spectrum fungicides, or difenoconazole, or antibiotic fungicides can be selected, and they can also be mixed for use. When the incidence rate is above 5% and there is a trend of spread, azole fungicides should be selected. Of course, they need to be used together with plant growth regulators such as brassinolide and cytokinins. When the disease is especially severe, a comprehensive control method of mixing azole agents with broad-spectrum agents or antibiotic agents can be used.
7. Amistar: azoxystrobin. Amistar has a very broad fungicidal spectrum and is effective against most pathogenic fungi among the four major groups of disease-causing fungi: Ascomycota, Basidiomycota, Deuteromycota, and Oomycota. Treating multiple diseases with one product is a prominent feature of Amistar. Its mode of action differs from existing fungicides, it has high activity, and currently the resistance of pathogens to Amistar is relatively weak. Its strongest advantage is preventive and protective action, not its curative action.
Its preventive and protective effect is more than ten to several dozen times that of ordinary protective fungicides, while its curative effect is almost no different from ordinary systemic curative fungicides. Therefore, to fully realize the effect of Amistar, it must be used before disease onset or in the early stage of disease. When Amistar is used during a severe period of disease, the disease-control effect will not be obviously different from that of other systemic fungicides. In order to fully realize Amistar's disease-control and yield-increasing effects, according to usage experience in various places, using Amistar in the following three periods is most suitable: first, in the seedling stage on seedling beds; second, before flowering; and third, in the early stage of fruit growth. Sufficient spray water volume is also an important factor in ensuring the effect of Amistar. In Shouguang, generally a 50-60 m long greenhouse at the adult plant stage (tomato, cucumber, eggplant, sweet pepper) must spray at least 4 sprayer tanks of water (120 jin), and an 80 m long greenhouse must spray 6-7 sprayer tanks of water. The concentration used is all 1500-fold solution (add 1 packet of Amistar per sprayer tank of water), with a spraying interval of 10-15 days each time, for 2-3 consecutive sprays. Amistar is generally used alone, and special attention must be paid to this.
8. Kocide: it belongs to copper hydroxide, and its trade names are also known as Kocide, Funguran, Blue Shield, etc. On vegetables it can be used to control bacterial diseases. Because of its strong protective action, it can be used before disease onset to control fungal and oomycete diseases. Because it is inorganic copper and also alkaline, it can only be mixed with organic fungicides that are structurally stable, such as chlorothalonil, etc. It cannot be mixed with acidic drugs. It is also not suitable for mixing with drugs containing metal ions or foliar fertilizers. It is also not suitable for mixing with thiram, thiophanate-methyl, carbendazim, diethofencarb, etc., which undergo chemical reactions when mixed, and mixing should also be avoided with those that produce sedimentation, coagulation, or other colloid-destroying phenomena after mixing. For those not yet clear, a test should be done first before determining, so as to avoid phytotoxicity.
9. Zineb: it can control diseases caused by many fungi, but has poor effect on powdery mildew. For controlling tomato early blight, late blight, leaf spot, leaf mold, anthracnose, gray mold, eggplant phytophthora blight, brown spot, etc., note that Cucurbitaceae vegetables are sensitive to zinc, and the concentration must be strictly controlled when using, and cannot be too high.
10. Propineb: it is a broad-spectrum, fast-acting protective fungicide. Another name is Antracol. For controlling Chinese cabbage downy mildew, cucumber downy mildew, tomato early and late blight, propineb is a protective fungicide and must be sprayed before disease onset or in the initial stage. It must not be mixed with copper preparations or alkaline agents.
11. Cymoxanil: its mechanism and characteristics are mainly to prevent pathogen spores from germinating, and it also has a killing effect on pathogens that have invaded the host. It has protective, curative, and systemic action, and is effective against downy mildew and phytophthora blight. Used alone, cymoxanil has a short effective period; mixed with protective fungicides such as propineb, it can prolong the residual period. Suitable crops include cucumber, grape, pepper, potato, tomato, etc. Targets of control include downy mildew and phytophthora blight, etc.
12. Dimethomorph: other Chinese name: Acrobat. It is widely used for control of vegetable downy mildew, phytophthora blight, seedling damping-off, tobacco black shank, and other diseases caused by fungi of the class Oomycota in the phylum Mastigomycotina. It has systemic activity. Without considering resistance of pathogenic fungi, its efficacy is higher than that of metalaxyl, cymoxanil, phosethyl-Al, oxadixyl, etc., which are currently widely used. Used alone, it has a relatively high resistance risk, so it is often compounded with protective fungicides such as mancozeb to delay the development of resistance.
13. Metalaxyl: it mainly controls Phytophthora diseases and is effective against millet downy mildew. Long-term single use of this drug makes pathogens prone to developing resistance. Other names: Apron, Baozhongling, Ridomil, Ridomil, Metalaxyl, Redomil, Aminopropropyl. Systemic fungicide, with protective and curative action, has bidirectional translocation performance, residual period 10-14 days, and soil treatment residual period can exceed 2 months. Scope of application: for timely spraying protection in the early stage of disease of various crop downy mildews, Phytophthora diseases, and rot diseases caused by downy mildew fungi, Phytophthora fungi, and rot fungi in melons, fruits, and vegetables, 25% metalaxyl wettable powder 800-1000-fold solution, 58% metalaxyl mancozeb wettable powder 500-fold solution, 40% phosethyl-Al wettable powder 300-fold solution, 64% Sandofan M8 wettable powder 400-500-fold solution, 77% Kocide wettable microparticle powder 500-fold solution can be selected, sprayed once every 7-10 days, for 2-3 consecutive sprays.
14. Quintozene main: quintozene main is also known as soil fungicide. It is used as soil and seed treatment. It has good control effect on seedling-stage diseases of many vegetables and soil-borne diseases. Mixing quintozene with 50% thiram wettable powder, or 50% carbendazim wettable powder, or 50% captan wettable powder at 1:1 for seed dressing or soil treatment can expand the types of diseases controlled and improve the control effect. When used as soil treatment, in heavy clay soil, the dosage should be appropriately increased to ensure efficacy. However, tomato seedlings, onion, lettuce, etc. are relatively sensitive to quintozene, and excessive amounts easily cause phytotoxicity, so increasing the dosage must be done cautiously. After applying the pesticide in the seedbed, appropriately spray (irrigate) more water to prevent phytotoxicity.
15. Bromothalonil: use is as a broad-spectrum, high-efficiency, low-toxicity fungicide, capable of inhibiting and eradicating the growth of fungi, bacteria, and algae, with good control effect on crop diseases and special efficacy against anthracnose. It is widely suitable for fruit trees, grapes, vegetables, cotton, peanuts, watermelon, tobacco, tea trees, flowers, and many other crops, controlling anthracnose, black spot, scab, powdery mildew, rust, damping-off, seedling blight, root and stem rot, canker, bacterial wilt, angular leaf spot, and many other fungal and bacterial diseases. The application method is flexible; foliar spraying, seed treatment, and soil root irrigation all show good control efficacy. It is also suitable for algae removal in lake environment treatment and improving fishery pond water quality; antisepsis and anti-toxin treatment of textiles, leather, etc.
16. Folpet: it is a broad-spectrum protective fungicide. Folpet has good preventive and protective effects on downy mildew, leaf spot, etc. of many vegetables. For controlling downy mildew and powdery mildew of cucurbits and other vegetables, and early blight and late blight of potato and tomato, spray with 50% wettable powder 500-600-fold solution. (1) It cannot be mixed with alkaline substances or emulsifiable concentrates and oil formulations of insecticides. (2) When the concentration used on tomato is too high, phytotoxicity is likely to occur, so caution is needed when preparing the pesticide.
17. Fosetyl-aluminium: aliases phosethyl-Al, Phytophthora-killing spirit, blight-killing spirit. Phosethyl-Al is an organophosphorus systemic fungicide with protective and curative action. It has very good effects on downy mildew, phytophthora blight, and mold diseases, and is used more on fruit trees. At the same time, it has special efficacy against tobacco black shank, so it is used more on tobacco in the south. But at present, the market awareness of this product is not yet high enough and its application is not broad enough; this is all caused by insufficient promotion. But as far as the product is concerned, it is a low-residue organophosphorus fungicide that can be systemically translocated upward and downward, with significant efficacy, and is a product with great market potential. At present, because trisodium phosphonate is exported in relatively large amounts and there are limited manufacturers, sales of this product in the domestic market are relatively low. This product can be translocated upward and downward within the crop. Apple Phytophthora fruit rot is relatively severe, and the effect is good, but application before bagging in the early stage is not safe for the fruit surface and easily causes mottled fruit, so it is difficult for fruit growers to accept.
The above summarizes the small techniques for using seventeen common pesticides. Among them, some are specifically for vegetables, some are specifically for melon and fruit agricultural products, and some are drugs specifically for a certain pest or a certain type of pathogen. When using them, they must be targeted, and indiscriminate use and excessive spraying must be avoided.