Method for researching insect resistance of foxtail millet variety to foxtail millet lepidogrammitis esculenta and field control effect of insecticide

Abstract

The invention discloses a method for researching the insect resistance of a foxtail millet variety to foxtail millet lepilea beetle and the field control effect of an insecticide, which comprises the following steps of: researching the condition of the resistance of the foxtail millet variety to the foxtail millet lepilea beetle, and then researching the field control effect of the insecticide to the foxtail millet lepilea beetle. A systematic research method is provided, millet varieties cultivated in various regions are collected, the resistance conditions of different varieties to millet lepidogrammitis esculenta are identified firstly, and the varieties with high insect resistance are screened out. Besides, the prevention effect of common pesticides with permeation, contact toxicity, stomach toxicity and the like on millet leaves in the market can be verified, an appropriate pesticide is screened out and used for preventing and treating harm of the pests, the millet yield is increased, and theoretical guidance is provided for millet planting.

Description

Technical Field

[0001] The invention relates to the technical field of agricultural planting research, and more specifically to a method for studying the insect resistance of a millet variety to millet leaf beetles and the field control effect of insecticides. Background Art

[0002] Millet has a long history of cultivation. It is rich in nutrients, with a starch content of up to 60.9%, a protein content of 12.3%, an amino acid and mineral content of about 3.3%, and a cellulose content of about 6.7%. In addition, it contains a variety of vitamins (Vb1, VB2, VB3, VB5) and antioxidants. Millet is a coarse grain crop with both medicinal and edible value. It is widely used for food and feed, such as millet, rice vinegar, millet rice crust, millet hypoglycemic cake, etc.

[0003] The occurrence of millet pests and diseases seriously restricts the increase of millet production. With the adjustment of planting structure and planting pattern, most areas in the northern region have planted millet on a large scale, which is very easy to cause millet pests and diseases. Among them, the millet leaf beetle Oulema tristis (Herbst) is a serious pest in millet production areas. It is an important pest in the main millet production areas at this stage. The millet leaf beetle belongs to the family Chrysomelidae of the order Coleoptera, also known as the millet mudworm. It has one generation per year in the north. The larvae mainly harm millet, broomcorn, corn and other grass crops. The newly hatched larvae drill into the heart leaves of the host plant to feed and form short white stripes. The adults feed along the leaf veins. When the insect occurs lightly, the host plant grows poorly and the grains are not full. When the insect occurs severely, the number of insects per 100 plants exceeds 300, causing the plants to wither and die in large areas. In recent years, with the continuous development of the millet industry in our region, the occurrence area and degree of millet leaf beetles in our region have gradually increased, and the effective prevention and control of millet leaf beetles has received much attention.

[0004] The breeding of insect-resistant varieties is an important means of plant disease and pest control. The nutrients in plants, such as soluble sugars, proteins, and amino acids, are not only essential for plant growth and metabolism, but also participate in the insect resistance of plants. In addition, the secondary metabolites of plants, such as phenols, terpenes, amines, and alkaloids, are all related to the insect resistance of plants. Polyphenol oxidase, superoxide dismutase, and peroxidase in plants are also related to the insect resistance of plants. Abscisic acid, salicylic acid, and jasmonic acid in plants are also related to insect resistance, which has been verified in crops such as wheat, cucumber, and alfalfa. The breeding of transgenic insect-resistant varieties has become a hot topic in current research. The success of transgenic cotton has attracted more scientific researchers to this work, and transgenic insect-resistant corn, soybeans, and rice have gradually entered people's eyes. The use of insecticides is extremely common in agricultural pest control. They have high insecticide efficiency and fast knockdown speed. Low-toxic insecticides are highly praised, especially pyrethroid insecticides, such as highly effective cyhalothrin, which have good insecticide effects on pod borers, thrips, weevils, etc. Environmentally friendly biogenic insecticides such as matrine, avermectin, and spinetoram are also often used to control aphids, thrips, whiteflies, weevils, etc. There are many types of insecticides on the market, and it is extremely important to screen out high-efficiency and low-toxic insecticides for the control of millet leaf beetles. Summary of the invention

[0005] In view of this, the present invention provides a systematic screening method to provide a theoretical basis for the selection of millet varieties and the use of drugs in producing areas.

[0006] To achieve the above object, the present invention adopts the following technical solution:

[0007] A method for studying the insect resistance of millet varieties to millet leaf beetles and the field control effect of insecticides comprises the following steps:

[0008] Step 1: Study on the resistance of millet varieties to millet leaf beetle

[0009] Collect different varieties of millet, plant them in different areas in the experimental plots, take samples of each variety when the millet leaf beetle breaks out, count the damage of millet leaf beetle larvae on different varieties, and evaluate the insect resistance of different varieties;

[0010] Step 2: Field study on the efficacy of insecticides against millet leaf beetles

[0011] Different pesticides were selected to set up different treatment groups in the field, and protection rows were set up between the treatment groups. Samples were taken to count the insect population base before application and the number of residual insects after application, and the insect population reduction rate and corrected control effect were calculated.

[0012] Preferably, step 1 is repeated 5 times for each variety planting area.

[0013] Preferably, in step 1, the millet is planted at a row spacing of 40 cm, a hole spacing of 8 cm, and 2 plants per hole.

[0014] Preferably, in step 1, sampling is performed at 5 points in each area for each variety, with 10 plants at each point.

[0015] Preferably, in step 2, each treatment group of different pesticides is replicated 5 times.

[0016] Preferably, step 2 also includes a blank control group.

[0017] Preferably, in step 2, sampling is performed at 5 points in each treatment group, with 10 plants at each point.

[0018] Preferably, in step 2, samples are taken on the 1st, 3rd and 7th days after the application of the drug.

[0019] Preferably, the insect population reduction rate and the corrected control efficacy in step 2 are calculated as follows:

[0020] Insect population reduction rate (%) = [(number of live insects before application - number of live insects after application) / number of live insects before application] × 100

[0021] Corrected control efficacy (%) = [(insect population reduction rate in treatment area - insect population reduction rate in control area) / (1 - insect population reduction rate in control area)] × 100.

[0022] It can be seen from the above technical solutions that, compared with the prior art, the present invention discloses a method for studying the insect resistance of millet varieties to millet leaf beetles and the field control efficacy of insecticides, which has the following beneficial effects:

[0023] The invention provides a systematic research method, by collecting millet varieties cultivated in various places, first identifying the resistance of different varieties to millet leaf beetles, and screening out varieties with stronger insect resistance. In addition, the prevention effect of common market-based insecticides with penetration, contact, stomach poison and other types on millet leaves can be verified, and suitable insecticides can be screened out to prevent and control the harm of the pest, increase millet yield, and provide theoretical guidance for millet planting. DETAILED DESCRIPTION

[0024] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Example 1

[0026] Test varieties: To evaluate the resistance of different millet varieties to millet leaf beetles, 40 millet varieties were provided by various research institutes, see Table 1.

[0027] Table 1 Test varieties

[0028]

[0029]

[0030]

[0031] Test insecticides: A total of 6 chemical insecticides and biological insecticides commonly found in local agricultural supply stores were selected. The names, sources, field dosages and recommended field dosages of the insecticides are detailed in Table 2.

[0032] Table 2 Test drugs and dosages

[0033]

[0034]

[0035] Note: AS: aqueous solution; SC: suspension concentrate; EC: emulsifiable concentrate; EW: emulsion in water.

[0036] Evaluation of insect resistance: The 40 millet varieties in Table 1 collected in the spring of 2024 were subjected to a randomized block experiment with 5 replicates per variety. 2 The row spacing was 40 cm, the hole spacing was 8 cm, and there were 2 plants in each hole. The seeds were sown on May 3 in Gaomaoquan Village, Qingshuihe County, Hohhot City (E: 111°60'55”; N: 39°97′39”). On June 25, when the millet leaf beetle broke out, samples were taken from 5 points in each plot for each variety, with 10 plants in each point, for a total of 50 plants. The damage caused by the millet leaf beetle larvae on different varieties was counted, and the insect resistance of different varieties was evaluated. The results are shown in Table 3.

[0037] Table 3 Test varieties and insect population density

[0038]

[0039]

[0040]

[0041] For 40 millet varieties sown at the same time, the occurrence of millet leaf beetles in different millet varieties was investigated and counted on June 25, the jointing period, when the millet leaf beetles were most serious. As shown in Table 3, the insect resistance of the 40 millet varieties to millet leaf beetles is as follows from high to low: Zhangzagu 14, Longgu 25> Jinmiao K12> Jizajinmiao 5> Chigu K4> Tonggu 1> Jinmiao K8> Chigu K6, Longgu 23, Zhangzagu 29> Zhangzagu 10> Jiugu 45> Jizajinmiao 6> Jinmiao K1> Zhongzagu 79> Jinmiao K11> Menggu 4 >Nenxuan 20>Jinmiao Bangbang>Jinmiao K7>Chijingu 29>Menggu 2>Chijingu 16>Jinmiao K4>Zhonggu 32>WZG-2023, Zhonggu 29, Zhonggu 303>Zhonggu Valley 19> Chaogu 26> Chaozagu 2, Gonggu 98> Jizagu No. 8> Zhongzagu 90> Zhonggu 30> Nenxuan 19> Zhangzagu 27> Menghonggu No. 2> Jizagu No. 10> Zhonggu 33.

[0042] Longgu 25, bred by the Crop Research Institute of Gansu Academy of Agricultural Sciences, and Zhangza 14, bred by Zhangjiakou Academy of Agricultural Sciences, had the strongest insect resistance, with an insect population density of 20.8 per 100 plants. Although Jinmiao K12 and Jiza Jinmiao 5 were not as resistant to insects as the previous two varieties, they were generally more resistant to insects, with insect population densities of 27.2 and 31.2 per 100 plants, respectively. Chigu K4, Tonggu 1, Jinmiao K8, Zhangzagu 29, Longgu 23, Chigu K6, and Zhangzagu 10 had insect population densities of less than 50 per 100 plants, and had relatively good insect resistance to millet leaf beetles. The results of insect resistance difference analysis showed that the above seven varieties had no significant difference in insect resistance with Longgu 25, Zhangza 14, Jinmiao K12, and Jiza Jinmiao 5 (P>0.05). Compared with the other 29 varieties, the above 11 varieties have better advantages in resisting the damage of millet leaf beetles, and the difference in insect resistance is significant (P<0.05).

[0043] The statistical results showed that Zhonggu 33 had the worst insect resistance. During the peak period of millet leaf beetles, the larval population density was as high as 96 per 100 plants, followed by Jizagu 10 with 94.4 per 100 plants. In addition, Menghonggu 2, Zhangzagu 27, Nenxuan 19, Zhonggu 30 and Zhongzagu 90 also suffered relatively serious larval damage, with the population density exceeding 75 per 100 plants. The insect resistance of these seven varieties was relatively weak. The results of the difference analysis of insect resistance of different varieties showed that there was no significant difference in the insect resistance of these seven varieties to millet leaf beetles (P>0.05).

[0044] Field efficacy experiment: Six common insecticides available in local agricultural supply stores were selected and used to carry out field efficacy experiments on the “Mongolia No. 2” variety planted in Gaomaoquan Village, Qingshuihe County, Hohhot City (E: 111°60'55”; N: 39°97′39”) and Yadaying Village, Xinghe County, Ulanqab City (E: 113°93′62”; N: 40°62'97”). In addition to testing the effects of the six insecticides used alone, the field efficacy of highly effective cypermethrin mixed with chlorfenapyr and spinetoram in a 1:1 ratio was also tested (see Table 2 for details). A total of 9 treatments were designed for the experiment, including 8 treatments and 1 blank control, with 5 replicates for each treatment and a plot area of ​​50m for each replicate. 2 The treatment groups were randomly arranged, and protection rows were set between the treatment groups. Each treatment was sprayed manually according to the field test usage in Table 2 (Taizhou Blue Sprayer Co., Ltd.: 3WBD-16 electric sprayer). Before spraying, 5 points were sampled in each plot, with 10 plants at each point, for a total of 50 plants. The insect population base of each plot before spraying was counted. On the 1st, 3rd, and 7th day after spraying, the number of residual insects was counted, and the insect population reduction rate and corrected control effect were calculated.

[0045] All data were statistically analyzed using Excel 2021 software to evaluate the insect resistance of different millet varieties and calculate the insect population reduction rate and corrected control effect after treatment with different insecticides. SPSS26.0 was used for one-way analysis of variance, and Duncan's new multiple range method was used to analyze the significant differences in insect resistance of different varieties and field control effects of different pesticides.

[0046] Insect population reduction rate (%) = [(number of live insects before application - number of live insects after application) / number of live insects before application] × 100

[0047] Corrected control efficacy (%) = [(insect population reduction rate in treatment area - insect population reduction rate in control area) / (1 - insect population reduction rate in control area)] × 100.

[0048] The results are shown in Tables 4-6.

[0049] Table 4 Field efficacy of different insecticides against millet leaf beetles in Qingshuihe County

[0050]

[0051]

[0052] Table 5 Field control effects of different insecticides on millet leaf beetles in Xinghe County

[0053]

[0054]

[0055] Table 6 Field control effects of different insecticides on millet leaf beetles in Xinghe County

[0056]

[0057]

[0058] The above results show that in the field control of millet leaf beetles in Xinghe County, within the 7 days of the investigation, the corrected control effect of the insecticide gradually increased with the increase of time after application, whether it was a single formulation or a mixed insecticide. One day after the application, the corrected control effect of high-efficiency cypermethrin was the highest at 83.82%, and the corrected control effect of high-efficiency cypermethrin mixed with chlorantraniliprole and spinetoram was higher and exceeded 76%, which was not significantly different from the corrected control effect of high-efficiency cypermethrin alone (P>0.05). There was no significant difference between the corrected control effect of chlorantraniliprole and avermectin benzoate (P>0.05), but the corrected control effect was significantly better than that of the biological insecticides avermectin (48.50%), spinetoram (57.86%) and matrine (52.38%) (P<0.05). After 3 days of application, the corrected control effect of cypermethrin was still the highest at 89.55%, which was not significantly different from the mixed treatment group (P>0.05). The corrected control effect of avermectin was the lowest at 61.75%. After 7 days of application, cypermethrin, chlorfenapyr, emamectin benzoate, cypermethrin + chlorfenapyr and cypermethrin + spinetoram showed good control effects, all exceeding 83%, and there was no significant difference in the corrected control effects among these insecticides (P>0.05). Among them, the combination of cypermethrin + chlorfenapyr had the best corrected control effect, with a control effect of up to 92.64%. The control effects of these five groups of insecticides were significantly higher than those of the biological insecticides avermectin, spinetoram and matrine (P<0.05), but the control effects of these three biological insecticides were all higher than 72%.

[0059] The results of the field efficacy experiment in Gaomaoquan Village, Qingshuihe County were similar to those in Xinghe County. Within 7 days after application, the corrected control effect of each agent increased with the increase of time after application. One day after application, the corrected control effects of high-efficiency cypermethrin, high-efficiency cypermethrin + chlorfenapyr and high-efficiency cypermethrin + ethyl spinetoram were the best, which were 81.63%, 77.62% and 76.64% respectively, and there was no significant difference in the corrected control effect among the three treatments (P>0.05). There was no significant difference in the corrected control effect of chlorfenapyr (63.28%) and avermectin benzoate (58.62%) (P>0.05), which was significantly lower than the above three treatments (P<0.05), but significantly higher than the corrected control effect of avermectin (35.68%) and ethyl spinetoram (42.02%) (P<0.05). The corrected control effect after 3 days of application was consistent with the trend after 1 day of application. After 7 days of application, the corrected control effect of chemical insecticides was significantly higher than that of biological insecticides. Except for the corrected control effect of avermectin benzoate, which was lower at 74.15%, the corrected control effects of other insecticides were all greater than 83%, among which the best was the combination of highly effective cypermethrin + chlorfenapyr, with a corrected control effect of up to 89.53%, and the lowest was matrine at 63.54%.

[0060] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the embodiments can be referred to each other. The above description of the disclosed embodiments enables professionals and technicians in this field to implement or use the present invention. Various modifications to these embodiments will be obvious to professionals and technicians in this field, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown in this article, but will comply with the widest range consistent with the principles and novel features disclosed herein.

Claims

1. A method for studying the insect resistance of millet varieties to millet leaf beetles and the field control efficacy of insecticides, characterized in that: The following steps are involved: Step 1: Study on the resistance of millet varieties to millet leaf beetle Collect different varieties of millet, plant them in different areas in the experimental plots, take samples of each variety when the millet leaf beetle breaks out, count the damage of millet leaf beetle larvae on different varieties, and evaluate the insect resistance of different varieties; Step 2: Field study on the efficacy of insecticides against millet leaf beetles Different pesticides were selected to set up different treatment groups in the field, and protection rows were set up between the treatment groups. Samples were taken to count the insect population base before application and the number of residual insects after application, and the insect population reduction rate and corrected control effect were calculated.

2. The method for studying the insect resistance of a millet variety to millet leaf beetle and the field control effect of insecticides according to claim 1, characterized in that: Repeat step 1 five times for each variety planting area.

3. The method for studying the insect resistance of a millet variety to millet leaf beetle and the field control effect of insecticides according to claim 1, characterized in that: In step 1, the millet planting row spacing is 40 cm, the hole spacing is 8 cm, and there are 2 plants in each hole.

4. The method for studying the insect resistance of a millet variety to millet leaf beetle and the field control effect of insecticides according to claim 1, characterized in that: When sampling in step 1, 5 points of each variety and each area were sampled, with 10 plants at each point.

5. The method for studying the insect resistance of a millet variety to millet leaf beetles and the field control efficacy of insecticides according to claim 1, characterized in that: In step 2, each treatment group of different insecticides had 5 replicates.

6. The method for studying the insect resistance of a millet variety to millet leaf beetle and the field control effect of insecticides according to claim 1, characterized in that: Step 2 also includes a blank control group.

7. The method for studying the insect resistance of a millet variety to millet leaf beetle and the field control effect of insecticides according to claim 1, characterized in that: Step 2: Sampling: Sampling was done at 5 points in each treatment group, with 10 plants at each point.

8. The method for studying the insect resistance of a millet variety to millet leaf beetle and the field control effect of insecticides according to claim 1, characterized in that: Step 2: Take samples on the 1st, 3rd and 7th days after application.

9. The method for studying the insect resistance of a millet variety to millet leaf beetle and the field control effect of insecticides according to claim 1, characterized in that: The insect population reduction rate and corrected control effectiveness in step 2 are calculated as follows: Insect population reduction rate (%) = [(number of live insects before application - number of live insects after application) / number of live insects before application] × 100 Corrected control efficacy (%) = [(insect population reduction rate in treatment area - insect population reduction rate in control area) / (1 - insect population reduction rate in control area)] × 100.

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