Herbicide phytotoxicity: 70% due to poor application technology

With the increase of labor costs and the acceleration of the land transfer process, the current application of herbicides has become very common, followed by the frequent occurrence of herbicides
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According to statistics, nearly 50% of the crop fields in the country have different degrees of phytotoxicity, and they have a tendency to increase year by year, which has severely affected the benefits of agricultural production and the adjustment of planting structure, and has become a stubborn disease in the process of agricultural production and herbicide application.

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The specific performance is: traditional long-residue herbicides such as chlorimuron-methyl and olesulfuron-methyl, as the dosage decreases year by year, the phytotoxicity of the following sensitive crops has a downward trend; new long-residue herbicides, such as fomesafen The phytotoxicity caused by ether, mesotrione, flumetsulam, quinclorac, etc.
to subsequent crops has been increasing year by year; due to the continuous cropping of soybeans in some areas, the commonly used chemicals have been applied year after year and a variety of chemicals have been mixed.
Compounding causes compound residual phytotoxicity; the amount of herbicides is generally too high, which makes the occurrence of crop phytotoxicity worse year by year; the phytotoxicity caused by poor safety of some herbicides is also quite serious
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? How does the herbicide phytotoxicity happen? In summary, there are several reasons for the occurrence of herbicide phytotoxicity: one is the nature of the herbicide itself, such as poor safety, impurities or unqualified formulations, unreasonable formula, excessive content, and illegal hidden ingredients added, etc.

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? The second is the impact of environmental conditions
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Low temperature and rainy weather, windy weather, or incorrect application period can easily cause phytotoxicity.
For example, in rainy weather, leaching phytotoxicity occurs in low-lying areas of soybean and corn fields
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? The third is application technology
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Long-residual herbicides such as imidazopyr and chlorimuron-methyl can cause phytotoxicity to sensitive crops at low residual concentrations; herbicides can cause phytotoxicity due to excessive application, misuse, mixing, and improper selection of additives; incorrect application time, application Incorrect methods, poor performance of pesticide application equipment, backward spraying technology, incomplete cleaning of sprayers, and poor field preparation quality have caused pesticide damage
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? Four is the crop factor
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Crop species differences in tolerance to herbicides (such as different degrees of resistance to different varieties of rice anilofos), the difference in sensitivity of different growth stages of plants, and the quality of crops growing seedlings differences
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? Fifth, do not understand the history of medication in the field
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With the transfer of large areas of land, land contracting operators do not know the history of the use of drugs on the contracted land, and often cause residual pesticide damage due to the application of long-lasting herbicides in the last stubble
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? According to the survey, herbicides cause more than 70% of the phytotoxicity caused by the application technology
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? What are the types of herbicide phytotoxicity? ? One is the current season phytotoxicity
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For example, the herbicide damage caused by the application of fomesafen, acetochlor, and trimethoprim in the soybean field; the pesticide damage caused by the application of nicosulfuron and 2,4-D butyl ester in the post-emergence of the corn field (mainly manifested as corn malformation, heart disease) The leaves are whip-shaped, and the tassels cannot be extracted normally, which seriously affects the yield); the different degrees of phytotoxicity caused by the application of Ding·pu mixture on the rice seedbed; the blind application of unregistered herbicides on the miscellaneous bean plots such as black beans and kidney beans; The herbicide of clomazone is used for phytotoxicity caused by peanut and mung bean fields; application of 24-D butyl ester before the three-leaf stage or after the jointing stage of wheat causes phytotoxicity
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? The second is the residual phytotoxicity
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It is mainly manifested in the application of herbicides such as chlorimuron-methyl, fomesafen, imidazolium, and clomazone in soybean fields, resulting in phytotoxicity in subsequent sensitive crops such as corn, melons, potatoes, rice, and sugar beets
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In addition, in spring, low temperature and high humidity, onions, melons, watermelons and other crops after transplantation often show residual phytotoxicity in large areas
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? The third is drift phytotoxicity
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The droplets of the liquid medicine volatilize and drift with the wind, causing damage to the neighboring sensitive crops, such as the phytotoxicity of the neighboring broad-leaved crops and trees caused by the application of 24-D butyl ester and clomazone
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Generally speaking, the symptoms of conductive herbicides appear late, and the whole plant is often damaged.
In severe cases, the crop will be aborted and it is difficult to recover; the symptoms of contact herbicides appear quickly and urgently, and symptoms often appear in local crops.
The point is not harmed and can be alleviated
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? The correct application of the prevention of herbicide phytotoxicity is the key? Before applying the herbicide, read the label carefully to clarify the applicable crops of the herbicide, the appropriate application period and method, the control object, the safe dosage and the precautions for administration, avoid Use the wrong medicine or over-dose, avoid applying medicine and over-dose outside the safe medication period
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Especially when applying new herbicides, you must be more cautious, first test and demonstrate in a small area, and then apply it on a large area
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? Different herbicides target different crops, such as butachlor and acetochlor, bensulfuron-methyl and chlorimuron-methyl, although they are only one word apart, they are applied in the paddy field and the other in the dry field
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Even the same crops, in different growth periods or different next (season) crops, the herbicides applied are not the same
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For example, when selecting post-emergence herbicides, some corn varieties are more sensitive to nicosulfuron and are prone to phytotoxicity, such as Zhengdan 958, Yuyu 22 and other varieties
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Note for some products? It is clearly prohibited to use on corn inbred lines, sweet corn, glutinous corn and other varieties.
Care should be taken when choosing
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The herbicide liquid should be mixed evenly and sprayed evenly.
The herbicide must be fully dissolved before application, especially before the herbicide is mixed, and the herbicide should be mixed evenly by the second dilution method
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When spraying in the field, you must walk at a constant speed and spray evenly
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Use safe and advanced herbicide spray equipment and add spray additives
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After applying the herbicide, the sprayer should be thoroughly cleaned
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? Some herbicides have a long residual effect period, which will cause the seedlings of the next (season) sensitive crops to grow short, rot or die
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Therefore, when selecting herbicides, we must consider what crops will be planted in the next (season).
Beets, potatoes, melons, sorghum, rice, cotton, vegetables, etc.
cannot be used in the following seasons.
Sumosulfuron, chlorsulfuron, etc.
are used as herbicides for the previous crops; when the next crop is planting soybeans and wheat, the amount of atrazine should be reduced by half when the previous crop is selected
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Different crops have different sensitivity to different herbicides.
When selecting herbicides, we must pay attention to the impact on the next crop and the next crop
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· Spraying acetochlor in soybean fields.
Pre-emergence application is safe for soybeans.
However, after application, when it encounters low temperature and rainy conditions, especially in low-lying and prone to water plots, acetochlor can easily cause soybean phytotoxicity
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Therefore, when spraying acetochlor in soybean fields, environmental weather factors need to be considered
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Spraying atrazine on corn fields generally does not cause phytotoxicity, but when the dose is too large, it will cause slight damage to the corn, so the dosage should be strictly controlled
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? Field plots should be intensively cultivated, and the land should be level and free of potholes.
In addition, too large gaps in the land will cause the liquid medicine to leached to the roots of the crops, resulting in leaching and phytotoxicity
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