Lime sulphur was invented in 1851 to control pests and then developed into fungicides. Lime sulfur mixture is a substance that boils sulfur powder, quicklime and water in a certain proportion. The stock solution is a reddish-brown transparent liquid with the smell of hydrogen sulfide. Insecticidal, acaricidal and bactericidal effects, its virulence is mainly calcium polysulfide and a part of calcium thiosulfate, and at the same time it has strong alkalinity, strong corrosiveness, and has the effect of eroding the wax layer of insect epidermis.
Although it has been nearly 2 centuries, the superiority of lime sulfur mixture is still irreplaceable: 1. High-efficiency broad-spectrum of excellent characteristics: lime sulfur mixture has good medicinal effect on almost all diseases, pests and mites, especially in winter When applied at a certain temperature, the effect is as high as 80%. 2. Persistence: The effect of the stone sulfur mixture is about half a month, and the best effect lasts from 7 to 10 days. 3. Low residue: After the product is decomposed, the active ingredients play a role in sterilizing and killing mites, and the residual parts are compounds of calcium, sulfur and other elements, which are all absorbed by plants. It is an essential element for plant growth. 4. Economic price: The raw material price of the lime sulfur mixture is relatively low, the preparation process is simple and feasible, and the broad-spectrum efficiency is high, so it is economical.
In the cooking of lime sulfur mixture, if the cooking method is inaccurate, the desired control effect cannot be achieved. Therefore, it is very important for the majority of fruit tree farmers to manufacture qualified and high-quality lime sulfur mixture.
So, what problems do current fruit tree farmers generally have in cooking lime sulfur mixture?
1. The raw materials are unqualified. Buy lime and sulfur at will. Some limes are not completely calcined and contain certain stones, which affects the ratio of materials. The sulphur should be finely powdered rather than sulphur flakes or lumps.
2. Lime sulfur mixture should be “boiled” rather than “prepared”. Some fruit farmers often use the preparation method, that is, according to 1 part of lime, 2 parts of sulfur, and 10 parts of water, use part of the water to dissolve the lime, and the other part of the water to make the sulfur into a paste, then mix the two together and stir for 40 minutes It is used as a lime sulfur mixture.
3. The weighing is not accurate. Some fruit farmers are inaccurate in weighing the raw materials when cooking the lime sulfur mixture, resulting in an inappropriate formula.
4. The utensils used during cooking are inappropriate. The active ingredient of the lime sulfur mixture is calcium polysulfide, which is an alkaline compound that easily reacts with some metal elements, such as aluminum. the active ingredient.
5. The cooking time is too long. Most fruit farmers believe that the longer the cooking time of the lime sulfur mixture, the better the quality, and the cooking time is mostly more than 1 hour. In fact, the length of the brewing time should depend on the color of the “medicine”. If the temperature is kept at 100°C, the brewing time is 40 minutes. If the time is prolonged, the active ingredients of the medicine will be reduced.
6. The heat is inaccurate when cooking. When the potion is boiled, the heat is very important. When the water is not boiled, it should be simmered on a high fire. After the water is boiled, it should be kept at medium heat (the liquid should be boiled in the middle). After 15 minutes of boiling, some of the liquid will turn brown. The fire should be a little smaller (the liquid requires a small roll), and then keep it until the end of the cooking. Some fruit farmers have been using high fire for fear that the temperature is not enough;
7. The stirring speed is uneven during cooking. Stirring with a wooden stick when boiling the medicine is to make the temperature of the medicine liquid in the pot the same, and the ingredients are mixed and reacted evenly. Some stir violently during cooking, so that the formed calcium sulfide reacts with carbon dioxide in the air to form calcium carbonate and other substances, which reduces the efficacy of the medicine, and some do not pay attention to the agitation of the upper and lower liquids, which prolongs the duration of the liquid. Reaction time.