What problems should be considered when using herbicides in wheat fields?

In recent years, the varieties of herbicides in wheat fields have increased rapidly, and the types of related compounds have increased, with diverse action principles. If not carefully used, there will be problems such as phytotoxicity and decreased weeding effect. Therefore, when using herbicides in wheat fields, these problems must be considered:

1, reasonable selection of herbicides Any herbicide has a certain weeding spectrum. There are explosion-proof leaves, Francis, Gramineae, glossy leaves and breakwater. However, it is impossible for one herbicide to effectively control all weeds in the field, so improper selection of herbicides is not effective, so herbicides should be selected according to the main weed species in wheat fields.

Gramineae weeds were controlled by 6.9% (the active ingredient was n-octadecanazole) in 70 ml, and 40 kg of water was sprayed. Hard grass, pushing, pushing, wheat field and Gramineae weeds were before Bromus, early maturing, grain-saving wheat and ryegrass occurred. Control broad-leaved weeds such as descurainia sophia, Leymus chinensis, pig gizzard, senna leaf and cat's eye. From the heading stage of wheat to the 2-4 leaf stage of broad-leaved weeds, add 30 ml of 20% dragon (chloroacetic acid) oil per mu (spraying 50 ml of 20% dragon (chloroacetic acid) on average per mu, and riding 6.9% (the active ingredient is normal compound plants).

2, choose the best time Some farmers choose to use herbicides in the spring wheat field, and they will not use drugs until the early age and density of weeds are high. At this time, the weeds are old and patient, so it is necessary to increase the dosage of preventive treatment, which will easily increase the cost and cause harm to wheat, marquis and nearby crops.

Therefore, it is strongly recommended to use drugs in winter. Take Bayer's horse washing as an example, it is best to apply gramineous weeds to 3~5 leaves before frost (usually when seedlings appear). Small weeds, weak tolerance, good weeding effect, low dosage, low cost and good safety. The treatment period is from February 1 day to March 1 day. Before the crops turn green after winter, there should be 4-6 blades of grass, and it will be sunny for about 3 days, and there will be no frost and no water in the field.

3. Scientifically mixing each herbicide has a certain amount of herbicide. Similar herbicides can be used continuously for many years, and sensitive weeds gradually decrease and drug-resistant weeds increase. Mixing herbicides can expand herbicides and delay the emergence of drug resistance. The following three principles should be grasped when mixing herbicides. Herbicide mixing can not have antagonistic effect, if it has antagonistic effect, it may reduce the efficacy or cause the efficacy, so it is best not to mix it. For example, 6.9% of Lezheng Yuhua (riding) grass age cannot be mixed with 56% of dimethyl tetrasodium chloride and paraquat. If it is necessary to control broad-leaved weeds in drug fields, it must be used in combination with herbicides for more than 7 days.

Reduce the dosage of herbicides appropriately, such as 75% tribenuron-methyl, 56% tetrachlorodimethyl and 20% tetrachloro (clopidogrel acetic acid) mixed with bladder grass. When the mixture has no lipid protection and no synergistic effect, different drugs of herbicide are used according to normal dosage. For example, a normalized garland (riding a horse) can use a variety of broad-leaved weed herbicides such as Benzuron and Spalon (chlorofluorooxyacetic acid) according to the constant. Please read the label or instructions carefully before use and use the medicine according to the recommended instructions.

4. Pay attention to reading the instructions. The specific technical points and precautions of drugs are recorded in detail on the product label. Please ask for instructions when buying. Read the product label or instructions carefully before use and take the medicine according to the recommended instructions, so as to get twice the result with half the effort. Different wheat varieties have different sensitivities to pesticides, so it is best to test the varieties without pesticides first. We should not rashly treat wheat with drugs. We should always pay attention to the growth of wheat and use drugs in time to ensure the yield.

In short, the above are the precautions for using herbicides in wheat fields, so we must pay attention to them.