Sensitivity of Crops to Common Insecticides and Fungicides and Precautions for Use
① Take 200 g of scallions, chop them, soak them in 10 L of water for a day and a night, filter the liquid, and use it to spray the affected plants several times a day for 5 consecutive days. ② Take 200-300 g of garlic, crush it and extract the juice, dilute it with 10 L of water, and use it immediately to spray the plants. ③ Take 400 g of tobacco powder and soak it in 10 L of water for two days and two nights...
I. Sensitivity of crops to common insecticides1. Chlorpyrifos is prone to causing phytotoxicity when used during the melon seedling stage, and its use should also be avoided during the flowering stage of some crops.
2. Pesticides containing triazophos should not be used on fruit sugarcane, as they are prone to causing phytotoxicity.
3. Because phoxim decomposes easily when exposed to light, its use should be avoided during the watermelon growing period and during the seedling stage of radishes and leafy vegetables (or even avoided entirely during the growing period); for other crops, use under strong light conditions should be avoided.
4. Insecticides containing malathion, when used at high concentrations, are sensitive on cucurbits, pears, peaches, grapes, beans, cruciferous crops, and tomato seedlings, and should not be used.
5. Pesticides containing omethoate and dimethoate are prone to causing phytotoxicity when used at high concentrations on some sorghum varieties, mat grass, tobacco, jujube trees, peaches, plums, apricots, cherries, citrus, and olives, and their use should be avoided.
6. Pesticides containing trichlorfon, dichlorvos, and naled (a precursor of dichlorvos) are sensitive on the seedlings of corn, beans, and cucurbits, and cause phytotoxicity on sorghum.
7. Isocarbophos should not be used on fruit trees, vegetables, or mulberry orchards, and its use on peach trees tends to cause leaf drop and fruit drop.
8. Pesticides containing bisultap and monosultap are prone to causing phytotoxicity when used on cotton, beans, and potatoes, and their use on cruciferous crops during the hot, humid summer season is also prone to causing phytotoxicity. In production practice, bisultap has also been found to cause phytotoxicity on citrus, so it should be used with caution.
II. Sensitivity of crops to common acaricides
1. Frequent use of dicofol-type acaricides causes chronic phytotoxicity on citrus, leading to heavy leaf drop in winter (chlorine poisoning); eggplants are especially sensitive to it.
2. Acaricides containing azocyclotin are prone to causing phytotoxicity when used during the young shoot stage.
3. Acaricides containing machine oil or diesel oil will cause "mottled fruit" phytotoxicity when used during the fruit growing period.
4. High-content propargite pesticides, when used at excessively high concentrations under high humidity conditions, will cause phytotoxicity to the young tender tissues of citrus. In addition, feedback indicates that this type of acaricide is generally not used on papaya.
III. Sensitivity of crops to the use of common fungicides
1. When triazole fungicides are used at excessively high concentrations during the vegetative growth period of cucurbits and vegetables, they will cause plants to grow slowly, become short and stunted, and develop smaller but thicker leaves, so their use should be avoided during the vegetative growth period. At the same time, their use during the flowering and fruiting period of large jujube will produce deformed fruit.
2. Bordeaux mixture and lime sulfur mixture will cause phytotoxicity when used during the growing period of many crops.
3. Chinese cabbage is sensitive to copper preparations, so copper preparations should not be used on Chinese cabbage.
4. Inorganic copper preparations are prohibited during the flowering and young fruit stages of fruit trees, and should be used with caution in high-temperature and high-humidity weather. At the same time, they must not be mixed and used indiscriminately.
5. Fungicides with a high content of chlorothalonil should not be used on persimmon and pear trees, as they are prone to causing phytotoxicity.
6. Compound preparations with a high sulfur content are sensitive on cucumber, soybean, potato, peach, pear, and grape, and when used at high temperatures, the concentration should be reduced or the product should not be used.
7. Arsenical preparations will cause phytotoxicity when used during the persimmon growing period and on cucurbits, and the effect lasts for a relatively long time, so their use on these crops should be avoided.