2. The temperature of spraying weeding and the physiological survey of weeds: Spraying wheat herbicide in spring at the temperature of 12 ~ 15 will have a good weeding effect. Only post-emergence herbicides can be used to weed wheat in spring. For weeds that have been unearthed, after a winter hibernation, the cell tissue and sensory system in the body will be activated and awakened. This temperature is also suitable for the growth of most plants in nature
In fact, plants living in nature, like animals, have their own biological clocks and rest or exercise in a certain period. When animals rest, their bodies are basically at rest. When you are active, your body will have different shapes. These plants, such as weeds, seem to be at rest when they are still or moving. However, there are various physiological organs and cell tissues in their bodies, and the conduction system has been coordinating their growth. When the outside temperature is suitable for their activities, various organs and cell tissues in their bodies begin to become active. Its performance is: the organs of stems and leaves are active, the stomata are open, and nutrients are absorbed from nature and transported to all parts of the body. Therefore, when spraying herbicides at this temperature, the chemical components in herbicides will be absorbed by them. Only in this way can we achieve the best weeding effect.
3. Weeding mechanism of herbicides: the pharmacology of herbicides to kill weeds is: contact killing and stomach killing: contact killing means that herbicide liquid can kill weeds when it comes into contact with weeds; Stomach killing is an internal weeding method: that is, after spraying herbicide liquid on weeds, it is absorbed by weeds and kills weeds. Contact killing and stomach killing are the same pharmacology: when the temperature reaches 15 degrees, various molecules of chemical components in herbicides will become more active. When they enter weeds, they will quickly destroy the cell tissue in weeds and disturb their normal conduction system. Paralysis and failure of various organs in weeds, and finally wither and die.
02. Use of wheat herbicide 1. Classification of wheat herbicides: wheat herbicides can be divided into gramineous herbicides and broadleaf herbicides;
1. Gramineae herbicide: used to remove gramineous weeds. Gramineae weeds refer to monocotyledonous weeds, that is, lobular plants with seedlings growing in stems. Although wheat is a cultivated crop, it is also a gramineous plant. The most common weeds in Gramineae are: wild oats, Aegilops tauschii, milkweed and bitter bean seedlings. Herbicides suitable for spraying gramineous weeds in wheat fields are fenoxaprop-p-ethyl and propargyl oxalate.
2. Broad-leaved herbicide: used to remove weeds from broad-leaved grass. It's also a dicotyledonous weed with big leaves. The most common weeds in this category are: spiny teeth, bitter wax vegetables, purslane and so on. Herbicides that kill this kind of weeds include tribenuron-methyl, bensulfuron-methyl and fluoroglycofen.
2. The dosage and spraying time of wheat herbicide:
1. Wheat herbicide is a single wheat herbicide, which is not suitable for mixing with other insecticides or fungicides. It is also not suitable for mixing with some foliar fertilizers. Because the safety agent is added to the wheat herbicide to protect wheat, the chemical components in those pesticides or fungicides and foliar fertilizer will destroy the chemical components of the safety agent in the herbicide and cause phytotoxicity to wheat or soil.
② The suitable time for spraying herbicides on wheat in spring is: before and after the wheat turns green, it is not allowed to spray herbicides when getting up and jointing. Wheat gets up to store nutrients for jointing, which is to grow the reproductive organs of wheat and create the necessary reproductive conditions for wheat booting and later flowering and mating. When you get up and start jointing, the chemicals in herbicides will inhibit the growth of wheat and destroy the formation of reproductive organs of wheat. It is difficult for wheat to complete flowering and pollination, which will make it difficult for wheat to bear fruit. What's serious is that your wheat grains are not harvested.
(3) When spraying, the prescription should be prepared according to the instruction manual, and the dosage should not be increased at will, so as not to cause phytotoxicity. Spraying should be carried out from 9: 00 am to 4: 00 pm on sunny days with high temperature.
(4) In order to increase the weed control spectrum, herbicides can be sprayed on wheat fields with both gramineous weeds and broad-leaved weeds. Reference drug: Gramineae herbicide 69% fenoxaprop-p-ethyl emulsion in water+broadleaf herbicide 75% tribenuron-methyl wettable powder+Land Rover. When dispensing, dispense the medicine according to the instructions for use: a. First dispensing: first, dilute and dissolve the three drugs with about 1 kg of clear water, and then dispense the medicine for the second time, that is, pour the diluted liquid medicine into a sprayer filled with clear water, stir it evenly, and then spray it for use.
Tips: Wheat herbicide is different from other pesticides. First, you should go to the formal agricultural sector to buy herbicides containing wheat safety protectants to avoid losses. Spray evenly to avoid spraying again or omission.