Use these medicines well for your succulents, and you will never have to fear death again
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Text and images: Curator
Many succulent growers who have only recently been exposed to succulents for a while often do not quite understand why so many people online need to sterilize their succulents and also need to kill insects, and what is sooty mold, what is black spot, and what are scale insects and root mealybugs, while they themselves seem to have no such needs at all. Could it be that they are exceptionally gifted and are truly experts at growing succulents, so they have no such troubles?
Of course that is not the case. The outbreak of pests and diseases usually takes time and accumulates over time. This is also one of the reasons why farmers practice crop rotation on the same field: to avoid the worsening of infection by a certain pest or disease of a certain crop. So even if you are not yet troubled by various fungal diseases, you should still honestly save this article, because as long as succulents are grown for one or two years, as long as you do not use medicine, sooty mold is basically unavoidable. The author below, Xiaoxixi Ya Diandiantou, has put together a relatively practical set of fungicides for succulents and introduced the usage and dosage in detail, while also pointing out the dangers of some pesticides. It is truly worth referring to.
From soil mix to leaf propagation, it seems that every step of succulent growing has a standard procedure, and as long as you follow it, nothing will go wrong. In fact, illness ultimately comes down to external causes. Everyone knows that too much water causes rot, liquefaction and black rot, so water must be controlled. But the culprit behind liquefaction and black rot is fungi. Too much water causes fungi to multiply massively, and it also causes soil oxygen deficiency, leading to malignant fungal growth, which finally breaks down the plant's surface defenses and invades the body. Since most plants have no immunity, once pathogens enter the plant body they can move unchecked, hence the legend of black rot killing overnight. So besides controlling water, what other way is there to prevent disease? That is sterilization. If growing methods can prevent disease at the source, then medicine is like blocking the enemy midway. Not only that, medicines are divided into many types. Besides fungicides and insecticides for disease and pest control, there are also medicines for regulating plant growth, and fertilizers as well. First are fungicides, then insecticides, and finally plant regulators and fertilizers. This article not only introduces usage and dosage, but also explains some common knowledge, which is very helpful for succulent growers who want to go deeper into succulent growing. My major is law, so my wording is objective and stiff. Please do not mind, and if there are shortcomings, experts are welcome to point them out. The following begins the main topic.
Overview of pesticide precautions:
1. Choice of pesticides There are many pesticide varieties on the market, pesticide quality varies greatly, and target pests and diseases also differ enormously. Therefore, pesticides must be chosen according to the target to be controlled, so that the medicine matches the problem, and do not use medicine blindly. Fungal infections use fungicides, pests use insecticides, nutrient deficiency uses fertilizers, and regulating plant growth uses plant growth regulators (such as rooting powder). Try to stick to major brands, such as Guoguang, Limin, Kesheng, DuPont...
2. Preparation of pesticides First, accurately weigh the amount of medicine and the amount of water, do not arbitrarily increase or decrease the concentration, and mix strictly according to the instructions. Plant growth regulators in particular are very sensitive to concentration. First use a small amount of water to make a stock solution, then dilute it.
3. Application of pesticides First, choose suitable equipment. For example, when spraying fungicides, choose a nozzle with smaller droplets; when spraying insecticides, a slightly larger nozzle can be chosen. Second, apply according to the weather. Do not spray in strong wind or rain; do not spray before rain; do not spray when there is dew; do not spray under high temperature and strong sun. Under high temperature, pesticides are highly volatile, and the medicine can enter the human body through breathing and skin pores, easily causing poisoning of the operator. Try to choose sunny and windless conditions, generally 8-10 a.m. (after dew has dried) and 5-7 p.m. (around sunset), and choose the time when pests are most active for spraying. Third, adopt corresponding application techniques according to different control targets. For example, pathogens are generally on the back of crop leaves, so when applying, be sure to spray the back of the leaves evenly; aphids generally occur on tender tips; mites are mostly on the back of older leaves in the inner canopy; and scale insect larvae are all on the roots. In addition, fungicides can generally be applied directly to plant wounds.
4. Safety protection Pesticides are toxic, so always pay attention to protecting yourself during use to prevent poisoning. Wear necessary protective equipment such as masks, gloves, protective clothing, and so on; no smoking, eating, or drinking during application; when applying, stand upwind; after application, promptly wash your body and change clothes.
5. Waste disposal After application, the remaining liquid and the wastewater used to wash sprayers should be properly handled and must not be dumped randomly. Under no circumstances should they be poured into rivers, lakes, seas, ponds, or fish ponds. Attention must be paid to environmental protection.
6. Avoid resistance Fungicides and insecticides should often be rotated with other medicines that have different mechanisms of action, to reduce the development of resistance.
7. Pesticides fully prohibited for use (23 types) Hexachlorocyclohexane (HCH), dichlorodiphenyltrichloroethane (DDT), toxaphene, dibromochloropropane, chlordimeform, ethylene dibromide (EDB), nitrofen, aldrin, dieldrin, mercury preparations, arsenic compounds, lead compounds, dithianon, fluoroacetamide, glucoflor, tetramine, sodium fluoroacetate, silatrane, methamidophos, parathion, methyl parathion, monocrotophos, phosphamidon.
8. Pesticides with restricted use (18 types) Omethoate is prohibited for use on cabbage; dicofol and fenvalerate are prohibited for use on tea trees; daminozide (B-nine) is prohibited for use on peanuts; terbufos is prohibited for use on sugarcane; phorate, isofenphos-methyl, terbufos, mephosfolan-methyl, phosfolan, demeton, carbofuran, aldicarb (the main culprit in the Shandong "toxic ginger" incident), ethoprophos, phosfolan, coumaphos, fonofos, chlorpyrifos, and fenamiphos are prohibited for use on vegetables, fruit trees, tea, and Chinese medicinal herbs.
Detailed description of commonly used fungicides:
1. Carbendazim Carbendazim is a highly effective, low-toxicity systemic fungicide with systemic therapeutic and protective effects. It is low in toxicity to humans, livestock, fish, bees, and so on. It is irritating to the skin and eyes. Oral poisoning causes dizziness, nausea, and vomiting. No carcinogenic, teratogenic, or mutagenic effects have been observed (this point is very important; try not to use carcinogenic medicines, and households with pregnant women must not come into contact with teratogenic or mutagenic medicines). Main formulations: 25% and 50% wettable powders, 40% and 50% suspension concentrates, 80% water-dispersible granules. Usage and dosage: (based on 50% wettable powder, with other concentrations calculated proportionally; this should not need to be taught, and those who do not know it should probably not read further) (1) Spraying: for household use, use 50% carbendazim at 800-1000 times dilution. The number of sprays and the amount should be determined according to disease development, spraying once every 7-10 days. (2) Root drenching: the concentration is the same as for spraying, drenching once every 10 days or so, and 2-3 consecutive drenches are enough. (3) Soil mixing: use 1 gram added to 1 liter of soil to make medicinal soil for planting. (4) Seed dressing and seed soaking: use 1 gram to dress every 100 grams of seeds. A seed soaking method may also be used: dilute 500 times, using 2 grams of carbendazim mixed with 1 liter of water, and soak the seeds for 2 hours. Precautions: (1) Spraying should preferably be done on cloudy days or on sunny afternoons, and if it rains within 6 hours after spraying, it should be reapplied. (2) Carbendazim can be mixed with general fungicides, but when mixed with insecticides or acaricides, it should be used immediately after mixing. (3) It cannot be mixed with alkaline medicinal fertilizers or copper preparations. (4) Diluted liquid, if not used temporarily, will show layering and needs to be shaken evenly before use. (5) For carbendazim, Guoguang is most recommended and is recognized as the best domestically. I also feel it is indeed good in use. To give just one example, other brands easily stick to the bottom when dissolving and easily precipitate after dissolving, while Guoguang dissolves as soon as it is rinsed and never sticks to the bottom, with no obvious precipitation even after standing for half an hour. Easy dissolution and little precipitation indicate that the powder is fine, so it is less likely to clog nozzles and damage spray bottles.
2. Chlorothalonil Chlorothalonil is a broad-spectrum, protective fungicide with no systemic conductive effect, but after being sprayed onto the plant, it has good adhesion on the surface and is not easily washed off by rain, so its efficacy lasts longer. Chlorothalonil is a low-toxicity fungicide, has an irritating effect on the skin of a small number of people, has an obvious irritating effect on the eyes of some people, and is highly toxic to fish (those who keep fish and shrimp at home must be extremely careful). Under experimental conditions it has no teratogenic or mutagenic effects. Main formulations: 40% suspension concentrate, 50% and 75% wettable powders, 75% water-dispersible granules, 10% oil miscible liquid, 5% and 25% granules, 2.5%, 10%, 30%, and 45% smoke agents, 5% dustable powder. Usage and dosage: (based on 75% wettable powder) Spraying: dilute 500-800 times. Depending on disease occurrence, apply once every 7 days or so, and it can be used continuously 2-3 times. When applying, spray evenly and thoroughly. Because it is a protective fungicide, equivalent to forming a protective film on the plant surface, it must evenly cover every leaf and branch, and especially do not forget the back of the leaves. Precautions: (1) For diseases that have developed resistance to carbendazim, switching to chlorothalonil gives better results. (In my years of experience, carbendazim + chlorothalonil can be called invincible.) (2) It should be used cautiously in fishery aquaculture. (3) When using, note that it cannot be mixed with alkaline pesticides such as Bordeaux mixture or lime sulfur mixture. (4) Chlorothalonil is an essential medicine for roses, used to control various fungal diseases such as black spot, brown spot, rust, powdery mildew, downy mildew, gray mold, anthracnose, leaf blight, leaf scorch, scab, leaf curl, and shot hole, practically all-purpose.
3. Triadimefon Also called Fenxiuning and Bailitong, it is the first widely used triazole fungicide. It has special effects on powdery mildew, rust, and smut, and thus earned the fine name "Fenxiuning". Triadimefon is a highly effective, low-toxicity, low-residue, long-lasting, strongly systemic triazole fungicide. It has preventive, eradicative, and therapeutic effects on rust and powdery mildew (the eradicative effect means complete cure, the strongest). It has a mild irritating effect on the skin, moderate toxicity to fish, and is harmless to bees and birds. Within experimental doses it has no carcinogenic, teratogenic, or mutagenic effects. Main formulations: 5%, 15%, and 25% wettable powders, 25%, 20%, and 10% emulsifiable concentrates, 20% paste, 25% colloidal suspension concentrate, 0.5%, 1%, and 10% dustable powders, 15% smoke agent. Usage and dosage: (based on 15% wettable powder) (1) Spraying: 15% wettable powder at 500-2000 times dilution. I recommend 1500 times, and 1000 times for severe disease. Determine the number of sprays and the amount according to disease development, spraying once every 7-10 days. (2) Seed dressing: use 1 gram of medicine to dress every 300 grams of seeds (not recommended). Precautions: (1) Triadimefon can be mixed with alkaline medicines, but cannot be mixed with copper preparations. (2) Seed dressing may delay seedling emergence by 1-2 days, but does not affect the emergence rate or later growth. (3) There is no specific antidote, and only symptomatic treatment is possible. (Now you know how formidable it is.) (4) Keep medication away from aquaculture areas, and it is prohibited to wash application equipment in rivers, ponds, and other water bodies; avoid contaminating water sources with the liquid. (5) Guoguang is still most recommended, for the same reason as with carbendazim.
4. Hymexazol Hymexazol, also called Tujunxiao, is a new type of systemic soil fungal fungicide and plant growth regulator. Its mechanism of action is unique. After entering the soil, it is absorbed by the soil and interacts with inorganic metal salts in the soil, more effectively inhibiting the germination of pathogen spores and the growth of mycelium. At the same time, it can promote plant growth, root tillering, root hair growth, increased root activity, enhanced cold resistance of seedlings, and improved seedling quality, achieving the effects of healthy seedlings and strong seedlings. Hymexazol has an extremely high penetration rate, moving to the stem in two hours and to the whole plant in 20 hours. Hymexazol is recognized as a pollution-free pesticide, and its various physical and chemical performance indicators fully meet environmental protection requirements. Main formulations: 8%, 15%, and 30% aqueous solutions, 15%, 70%, 95%, 96%, and 99% wettable powders, 20% emulsifiable concentrate, 70% seed treatment dry powder. Usage and dosage: (based on 30% aqueous solution) (1) Spraying: dilute 1200-1500 times. Determine the number of sprays and the amount according to disease development, spraying once every 7-10 days, 2-3 times is enough. (2) Root drenching: dilute 600-800 times. (3) Seed soaking: dilute 1000 times. Precautions: (1) It can be mixed with general pesticides and mutually increases their effects. (2) Safe, low-toxicity, residue-free, and environmentally friendly fungicide, it is the preferred pesticide for green food. (3) Low toxicity and environmental protection are advantages, but after all it is still toxic, so do not be careless. As for suicide, forget it; low toxicity means dying too slowly and suffering while alive.
5. Mancozeb Mancozeb is an excellent protective fungicide and belongs to low-toxicity pesticides. Because of its broad sterilization range and difficulty in developing resistance, its control effect is clearly superior to other similar fungicides, so its global usage has always been a large-tonnage product. The agent has an irritating effect on the skin and mucous membranes, and is toxic to fish. Main formulations: 70% and 80% mancozeb wettable powders, 80% Pencozeb, Dithane M-45, and Xinwansheng wettable powders. Usage and dosage: (based on 80% wettable powder) Spraying: dilute 800-1000 times. Depending on disease occurrence, apply once every 10-15 days or so, and it can be used continuously 2-3 times. When applying, spray evenly and thoroughly. Because it is a protective fungicide, equivalent to forming a protective film on the plant surface, it must evenly cover every leaf and branch, and especially do not forget the back of the leaves. Precautions: (1) During storage, prevent high temperature and keep it dry, so that under high temperature and humid conditions the agent does not decompose and reduce efficacy. (2) It cannot be mixed with alkaline or copper-containing pesticides. (3) It is toxic to fish, and water sources must not be contaminated. (4) The agent has an irritating effect on the skin and mucous membranes, so pay attention to protection when using it.
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