Flue-cured tobacco field chemical weeding method adapting to Yunnan climate characteristics

Abstract

The invention discloses a flue-cured tobacco field chemical weeding method adapted to Yunnan climate characteristics, which comprises the following steps: (1) after flue-cured tobacco seedlings are transplanted, performing film uncovering and hilling operation on a flue-cured tobacco field on the 6th-8th day before a rainy season comes in June, and removing a small amount of adult weeds around flue-cured tobacco on ridges; (2) after hilling is finished, chemical weeding is carried out on the flue-cured tobacco field by adopting a mixed herbicide before or after first effective rainfall; in the step (1), in the film uncovering and hilling operation, weeds around tobacco seedlings on ridges are removed during hilling so as to ensure that no perennial or large weeds exist on ridge surfaces; the chemical weeding method in the step (2) aims at special geographical climate and cultivation habits in the Yunnan region. About one week after flue-cured tobacco hilling is determined as a key period for weeding of the flue-cured tobacco field, chemical prevention and control are carried out, so that seedling emergence weeds are weak in growth vigor due to insufficient illumination and cannot effectively compete with tall flue-cured tobacco, and then ecological prevention and control of weeds between plants and rows are achieved through the advantages of flue-cured tobacco canopies.

Description

Technical Field

[0001] This application belongs to the technical field of green prevention and control of weeds in Yunnan flue-cured tobacco fields, and particularly relates to a chemical weeding method for flue-cured tobacco fields adapted to the climatic characteristics of Yunnan. Background Art

[0002] Yunnan is a major province and a strong province in flue-cured tobacco cultivation in the country. The quality of tobacco leaves is at an excellent level in the country. The quality of Yunnan flue-cured tobacco is inseparable from the unique climatic characteristics of Yunnan.

[0003] Among them, during the flue-cured tobacco planting process, after the flue-cured tobacco is transplanted, the film is usually broken and soil is banked up before the rainy season arrives. Subsequently, when the field weeds germinate, manual weeding or hoeing with a hoe is adopted. Since after soil banking, most flue-cured tobacco planting areas in Yunnan immediately enter the rainy season, the growth rates of both weeds and flue-cured tobacco accelerate. Before harvesting and curing, 3 - 4 times of weeding are required, and the labor demand is extremely large. In addition, as the flue-cured tobacco plants grow rapidly in height and expand, it is inevitable to cause mechanical damage to the tobacco leaves during inter-row weeding operations, affecting the quality of tobacco leaves. For some flue-cured tobacco fields without film breaking, the arrival of the rainy season and the damage of the film edge will cause the weeds under the film to grow rapidly. Especially in areas with concentrated rainfall, the weeds grow around the flue-cured tobacco, intensifying the competition for the flue-cured tobacco. If no manual weeding is carried out, the flue-cured tobacco will suffer more serious weed damage, and manual weeding is more difficult and costly. For flue-cured tobacco fields without film removal and soil banking, due to the relatively shallow soil layer, the growth condition of the flue-cured tobacco is not as good as that of the plants with film removal and soil banking, and its competitiveness against weeds is also weaker. In the initial stage of the rainy season, the flue-cured tobacco plants are small, the inter-row light is strong, and there is sufficient rain, so the weeds grow rapidly. At present, the rural labor force is limited, and the weeding work intensity is high. 3 - 4 times of weeding within one growing season is a heavy burden for farmers. Observations show that most flue-cured tobacco fields have problems of untimely weeding and relatively serious weed damage, and the weed damage has become the main factor restricting the healthy growth of flue-cured tobacco.

[0004] Among the many strategies for weed management, chemical weeding is considered to be an ideal measure because of its high efficiency, simplicity and low cost. Chemical control of weeds in crop fields is mainly achieved through two ways: soil treatment and foliar treatment. Soil treatment involves applying herbicides to the soil surface before weed germination to prevent the emergence of annual weeds. This method is usually implemented after land preparation. As a preventive measure, it usually can achieve remarkable control effects. Foliar treatment is to directly spray herbicides on the weed leaves after the weeds emerge, and the herbicides play a role through absorption and conduction by the leaves and stems. In the presence of crops, foliar treatment agents need to have selectivity, that is, they are effective against weeds and safe for crops. As a crop that is not widely planted, there are extremely limited varieties of selective foliar treatment agents for flue-cured tobacco. Therefore, it is difficult and less safe to control the weeds in the emerged flue-cured tobacco fields. Summary of the Invention

[0005] The technical problem to be solved by this application is to overcome the problems of lack of green weed control technology in most flue-cured tobacco areas in Yunnan in the prior art, untimely weeding in most flue-cured tobacco fields, and serious weed damage. The harm of weeds has become the main factor restricting the healthy growth of flue-cured tobacco. In the presence of crops, the stem and leaf treatment agent needs to be selective, that is, effective against weeds but safe for crops, and provide a chemical weed control method for flue-cured tobacco fields that is adapted to the climatic characteristics of Yunnan.

[0006] This application adopts the following technical solutions to solve the above technical problems:

[0007] The present application provides a method for chemical weed control in flue-cured tobacco fields adapted to the climate characteristics of Yunnan, comprising the following steps:

[0008] (1) After the tobacco seedlings are transplanted, on the 6th to 8th day before the rainy season in June, the tobacco fields should be covered with plastic film and soil should be cultivated, and perennial or large weeds around the tobacco on the ridges should be removed;

[0009] (2) After soil cultivation is completed, use a mixed herbicide to carry out chemical weed control in the tobacco field before or after the first effective rainfall.

[0010] In this application, the film is removed and soil is piled up in the flue-cured tobacco field, and the weeds around the flue-cured tobacco on the ridges are removed during the soil pile up to ensure that there are no large weeds on the ridge surface and to create conditions for weed control in the later stage.

[0011] Preferably, in step (1), when cultivating the soil, the topsoil layer with a thickness of 5-10 cm between the rows of flue-cured tobacco seedlings is piled on the ridges, and the film fragments on the ridges are cleaned. In the present application, the purpose of this step is to effectively cover some sporadic grass sprouts on the ridges, prevent them from sprouting, and create a grass-free environment; at the same time, the film fragments on the ridges are cleaned to prevent the film from hindering the conduction of the herbicide.

[0012] Preferably, in step (2), when chemical weed control is performed after the first effective rainfall, the herbicide should be sprayed when the ground is dry and no longer sticky within 1 to 2 days after the rainfall stops, so as to ensure that the pesticide is applied at the best time and that the ridge surface and the soil surface between rows are covered with the herbicide, thereby improving the weed sealing treatment effect and achieving full coverage of weed control within and between rows.

[0013] Preferably, in step (2), the mixed herbicide comprises pendimethalin emulsifiable concentrate, butachlor emulsifiable concentrate, and glufosinate-ammonium aqueous solution. In the present application, pendimethalin and butachlor are mainly used to prevent weeds that have not emerged. By mixing the two soil-applied herbicides, the herbicide spectrum is broadened and the herbicide dosage is reduced; while glufosinate-ammonium is used to kill a small amount of weeds that have emerged not long ago. At the same time, glufosinate-ammonium has a wide range of effects on various seedlings and a short residual period, and is safe for flue-cured tobacco. The mixed treatment of the three agents can not only control the weeds that have not emerged, but also effectively control a small amount of newly emerged weed seedlings, creating a good growth environment for the flue-cured tobacco to enter the vigorous growth period.

[0014] Preferably, the concentration of the pendimethalin emulsifiable concentrate is 300 - 350 g / L, and the dosage is 90 - 110 g / mu;

[0015] The mass fraction of the butachlor emulsifiable concentrate is 55 - 65%, and the dosage is 90 - 110 g / mu;

[0016] The mass fraction of the glufosinate-ammonium aqueous solution is 10 - 15%, and the dosage is 100 - 150 mL / mu.

[0017] Preferably, the concentration of the pendimethalin emulsifiable concentrate is 330 g / L, and the dosage is 100 g / mu;

[0018] The mass fraction of the butachlor emulsifiable concentrate is 60%, and the dosage is 100 g / mu;

[0019] The mass fraction of the glufosinate-ammonium aqueous solution is 11%, and the dosage is 120 mL / mu.

[0020] Herbicides are special agricultural materials. It is preferred to use qualified products with controllable quality produced by large pesticide manufacturers. Do not randomly purchase low-quality and low-cost products to avoid causing phytotoxicity and yield losses.

[0021] Preferably, in step (2), the mixed herbicide is applied by spraying.

[0022] Preferably, during the spraying process, a fan-shaped spray head is used;

[0023] The spray angle of the fan-shaped spray head ≤ 80°.

[0024] Preferably, during the spraying process, the fan-shaped spray head is 20 cm - 25 cm from the ground, and directional spraying is carried out around the tobacco plants in the row and between the rows to avoid directly spraying the liquid medicine on the leaves of the flue-cured tobacco; a protective cover can also be installed outside the spray head to reduce the frequency of liquid medicine splashing.

[0025] Second aspect:

[0026] In Yunnan, tobacco seedlings are transplanted in April during the dry season, and soiling is completed before the rainy season arrives in early June. During soiling, soil between rows is transferred to ridges and piled around the tobacco. At this time, the gaps between rows are large, and the tobacco has not yet entered the vigorous growth period. From the perspective of weed management, after the film is removed and soiling is carried out, it is an ideal time to use soil treatment agents to prevent weeds. With the rapid increase in ground temperature and the increase in rainfall intensity after soiling, weeds germinate and emerge quickly, and tobacco also quickly enters a rapid growth period, with plants growing rapidly and leaves spreading all around. When the weeds between and within the rows of tobacco grow to a level that is easy to weed, the operation becomes extremely difficult. If manual weeding is used, a large number of leaves will inevitably break; if chemical weeding is used, due to the limited space within and between rows, spraying is inconvenient and unsafe.

[0027] The present application has found through research that the critical period for weed control in the flue-cured tobacco field is determined to be about one week after the soil is filled up, and chemical control is carried out. The present application can effectively control weeds in and between rows for 30 to 45 days. After that, the flue-cured tobacco rows are closed, the plants are tall, the leaves become wider, and the light intensity in and between the rows on the surface is extremely weak. The newly emerged weeds have weak growth due to insufficient light and cannot effectively compete with the tall flue-cured tobacco. Then, the advantages of the flue-cured tobacco canopy are used to achieve ecological control of weeds between plants and rows.

[0028] On the basis of conforming to the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present application.

[0029] The positive progressive effect of the present application is that the weeding method provided by the present application does not need to be weeded again until the flue-cured tobacco enters the harvest period, because the bottom 3-4 leaves of the tobacco seedlings will be stained with mud and age and deteriorate, and will be removed in the later management. The liquid splashed when spraying the herbicide belongs to bud absorbers (butachlor and pendimethalin) and contact agents (glufosinate ammonium), both of which are short-acting pesticides and will not be transferred to the harvested tobacco leaves. The types and methods of herbicides used will not cause harm to the later growth of flue-cured tobacco, nor will they affect the quality and safety of the tobacco leaves. At the same time, the quality of the tobacco leaves is guaranteed, pesticide residues are reduced, and rural labor is greatly saved. There is no need for manual weed treatment, and the application prospect is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present application can be better understood by referring to the description given below in conjunction with the accompanying drawings. The accompanying drawings, together with the following detailed description, are included in this specification and form a part of this specification, and are used to further illustrate the preferred embodiments of the present application and explain the principles and advantages of the present application.

[0031] in:

[0032] Figure 1 The scene of farmers removing the film from flue-cured tobacco;

[0033] Figure 2 The situation of farmers earthing up flue-cured tobacco;

[0034] Figure 3 The schematic diagram of farmers spraying herbicide between the rows of flue-cured tobacco. Detailed implementation manners

[0035] The present application will be further described below by way of examples, but the present application is not limited to the scope of the described examples. For the experimental methods without specific conditions in the following examples, they are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0036] The experimental methods used in the following examples are all conventional methods unless otherwise specified.

[0037] The raw materials in the following examples are all commonly available in the market.

[0038] Example 1

[0039] (1) After transplanting the flue-cured tobacco seedlings, on the 7th day before the rainy season in June, the film covering and earthing up operation is carried out on the flue-cured tobacco field, and the weeds around the flue-cured tobacco on the ridge are removed. When earthing up, the topsoil within a thickness range of 5 cm between the rows is piled onto the ridge to remove a small amount of emerged small grass, and effectively cover the just-emerged small grass on the ridge to prevent it from emerging; at the same time, clean up the film fragments on the ridge to prevent the film from hindering the conduction of the herbicide.

[0040] (2) After the earthing up is completed, do not immediately spray the herbicide on the soil. Wait for 1 day after the first effective rainfall stops, and use three herbicides, namely 330 g / L pendimethalin emulsifiable concentrate at 100 g / mu, 60% butachlor emulsifiable concentrate at 100 g / mu, and 11% glufosinate-ammonium aqueous solution at 120 mL / mu, to carry out chemical weeding on the flue-cured tobacco field. The weeding is carried out by spraying. When spraying the herbicide, lower the spray head and use an 80° fan-shaped spray head. When spraying, the spray head is no more than 20 cm from the ground, and spray around the tobacco plants in the row and between the rows, and try to avoid directly spraying the liquid medicine on the flue-cured tobacco leaves. Through this weeding treatment, the weeds in the row and between the rows can be effectively controlled for 30 - 45 days.

[0041] Effect Example 1

[0042] Detect the weed incidence rate and the pesticide residues of the herbicide, and the results are shown in Table 1.

[0043] From Figures 1 to 3It can be seen that the smoke has sealed the rows, the plants are tall, the leaves are wide, and the light intensity inside and between the rows on the ground surface is extremely weak. The newly emerged weeds have weak growth potential due to insufficient light and cannot effectively compete with the tall flue-cured tobacco. After one herbicide treatment and timely fertilization to ensure that the flue-cured tobacco enters the rapid growth stage until it enters the harvesting stage, the flue-cured tobacco field does not need to be weeded again. Since the bottom 3-4 leaves of the tobacco seedlings will get dirty and age badly, they will be removed during the later management. The splashed liquid medicine during herbicide spraying belongs to bud absorbents (butachlor and pendimethalin) and contact killers (glufosinate), both of which are short-acting pesticides and will not transfer to the harvested tobacco leaves. The types and methods of herbicides used will not cause harm to the later growth of flue-cured tobacco nor affect the safety quality of the tobacco leaves.

[0044] Table 1

[0045]

[0046] As shown by the results in Table 1, the weed incidence rate of the traditional method is basically higher than 80%, and the weed incidence rate of the present invention is between 5% and 15%.

[0047] Effect Example 2

[0048] In Example 1 of this application, experimental applications have been carried out in the fields since 2021. The application areas include 16 flue-cured tobacco fields in Kunming, Kaiyuan, Luliang, Weishan, etc. for demonstration use. Four of them are selected for detection. According to the pesticide residue detection methods of the tobacco company's industry standards (YC / T 179—2004 and YC / T 405.2—2011), 19 herbicides listed in YQ-50-2014 "Maximum Residue Limits of Pesticides in Tobacco Leaves" are tested. The test results are shown in Table 2.

[0049] Table 2

[0050]

[0051]

[0052]

[0053] As can be seen from the results in Table 2, the types of herbicides listed are all below the detection line, and their contents are also lower than the detection standards of the newly revised "National Food Safety Standard Maximum Residue Limits of Pesticides in Foods" (GB 2763-2021) in China. It can be seen that compared with manual weeding in Example 1 of this application, there is no significant difference in the yield and quality of tobacco leaves, and it meets the standard of the maximum residue limits of pesticides in tobacco leaves (YQ-50—2014) (see the attached table), and no herbicide exceeding the standard phenomenon is found.

[0054] Finally, it should also be noted that in this application, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device.

[0055] Although the present application has been disclosed above through the description of specific embodiments of the present application, it should be understood that those skilled in the art can design various modifications, improvements or equivalents to the present application within the spirit and scope of the appended claims. These modifications, improvements or equivalents should also be considered to be included within the scope claimed by the present application.

Claims

1. A method for chemical weed control in flue-cured tobacco fields adapted to the climate characteristics of Yunnan, characterized in that: The steps include: (1) After the tobacco seedlings are transplanted, on the 6th to 8th day before the rainy season in June, the tobacco fields are covered with plastic film and soil is cultivated, and a small amount of adult weeds around the tobacco on the ridges are removed; (2) After the soil is cultivated, before or after the first effective rainfall, use a mixed herbicide to carry out chemical weed control in the flue-cured tobacco field; In step (1), the film is removed and soil is cultivated, and weeds around the tobacco seedlings on the ridges are removed during the soil cultivation to ensure that there are no perennial or large weeds on the ridge surface; In step (2), the chemical weed control method is tailored to the special geographical climate and cultivation habits in Yunnan.

2. The method for chemical weed control in flue-cured tobacco fields adapted to the climate characteristics of Yunnan as claimed in claim 1, characterized in that: In step (1), when cultivating the soil, a topsoil layer with a thickness of 5-10 cm between two flue-cured tobacco rows is piled on the ridges, and the film fragments on the ridges are cleared.

3. The method for chemical weed control in flue-cured tobacco fields adapted to the climate characteristics of Yunnan as claimed in claim 1, characterized in that: In step (2), the post-rainfall treatment is performed after the rainfall stops and the surface is dry and can no longer be touched by water 1-2 days later.

4. The method for chemical weed control in flue-cured tobacco fields adapted to the climate characteristics of Yunnan as claimed in claim 1, characterized in that: In step (2), the mixed herbicide includes pendimethalin emulsifiable concentrate, butachlor emulsifiable concentrate, and glufosinate ammonium aqueous solution.

5. The method for chemical weed control in flue-cured tobacco fields adapted to the climate characteristics of Yunnan as claimed in claim 4, characterized in that: The concentration of the pendimethalin emulsifiable concentrate is 300-350 g / L, and the dosage is 90-110 g / mu; The mass fraction of the butachlor emulsifiable concentrate is 55-65%, and the dosage is 90-110 g / mu; The mass fraction of the refined glufosinate ammonium aqueous solution is 10-15%, and the dosage is 100-150 mL / mu.

6. The method for chemical weed control in flue-cured tobacco fields adapted to the climate characteristics of Yunnan as claimed in claim 4 or 5, characterized in that: In step (2), the mixed herbicide is applied by directional spraying between plants or rows, and spraying the liquid directly onto the tobacco leaves is avoided as much as possible. It is best to add a spray protective cover.

7. The method for chemical weed control in flue-cured tobacco fields adapted to the climate characteristics of Yunnan as claimed in claim 6, characterized in that: During the spraying process, a fan-shaped spray head is used; The spray angle of the fan-shaped spray head is ≤80°.

8. The method for chemical weed control in flue-cured tobacco fields adapted to the climate characteristics of Yunnan as claimed in claim 7, characterized in that: During the spraying process, the fan-shaped spray head is 20 to 25 cm away from the ground, and the herbicide is sprayed around the tobacco plants in the row and between the rows in a directional spraying manner.

9. The method for chemical weed control in flue-cured tobacco fields adapted to the climate characteristics of Yunnan as claimed in claims 1 to 8 may further include measures such as timely fertilization, removal of the dominance of the terminal buds of tobacco leaves, promotion of tobacco leaf growth, early row closure, and reduction of the growth of weeds between rows.

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