CN115428809B - Compound seed dressing agent and wheat stem basal rot comprehensive control method - Google Patents

Abstract

The invention discloses a compound seed dressing agent and a wheat stem basal rot comprehensive control method, belonging to the technical field of plant disease control. The compound seed dressing agent is prepared by compounding a Paenibacillus polymyxa agent and a prothioconazole agent, has an excellent inhibition effect on fusarium, and can be used for preventing and controlling plant diseases caused by fusarium, such as wheat stem basal rot, so that the spread and popularity of the diseases are well controlled, the grain production safety is ensured, and the generation of plant disease and insect pest resistance is slowed down. Meanwhile, bactericides such as thifluzamide and the like are sprayed in the wheat green-turning period, so that the spread of diseases can be effectively restrained, joint defense is formed by the bactericide and the compound seed dressing agent, the comprehensive prevention and control effect is improved, a basis is provided for biological prevention and control of the wheat stem-based rot in the future, and the application prospect is wide.

Description

A compound seed dressing agent and a comprehensive prevention and control method for wheat stem base rot

Technical Field

The invention belongs to the technical field of plant disease prevention and control, and specifically relates to a compound seed dressing agent and a comprehensive prevention and control method for wheat stem base rot.

Background Art

Wheat stem base rot is an important fungal soil-borne disease caused by Fusarium infection, which is prevalent in wheat-producing areas. After sowing, wheat seeds are infected, which will cause them to rot before germination; when infected in the seedling stage, brown spots will appear on the leaf sheaths and stems at the base of the wheat stems. Multiple spots combined together will cause the wheat roots to turn brown and rot. When the disease is serious, the wheat leaves will turn yellow, wither and die; when the disease is serious in the later stage, it will spread to the sixth stem node; when the field environment is humid, red or white mold layers can be observed at the base of the stem nodes, eventually leading to dry white ears, small ears and barren grains, and reduced yields. In recent years, due to the large-scale promotion of returning straw to the field, the number of Fusarium in the soil has increased sharply. Therefore, wheat stem base rot caused by the combined infection of multiple Fusarium has been getting worse year by year, seriously threatening the safe production of wheat in my country.

At present, most of the main wheat varieties are susceptible to the disease, and no varieties resistant to wheat stem rot have been launched. Although agricultural measures such as deep plowing, deep loosening, crop rotation, and rapid straw decomposition in the wheat planting process have shown a certain control effect on the disease, in the current situation of straw burning ban and tight autumn planting time, returning straw to the field is the only effective way to quickly deal with straw. Chemical seed dressing has become a relatively effective means of prevention and control, but long-term reliance on chemical control will also lead to increased resistance to plant diseases, insects and weeds.

Summary of the invention

In the research on the prevention and control of wheat stem base rot, the present invention found that Paeniocollus polymyua can play a good inhibitory effect on wheat stem base rot. Based on this, the present invention uses Paeniocollus polymyua and other preparations in the form of a single agent or combination for seed dressing, and sprays fungicides during the greening period to explore a comprehensive prevention and control method for wheat stem base rot. On this basis, the present invention proposes the following technical solutions:

The invention provides the use of Paenibacillus polymyxa, which is to use Paenibacillus polymyxa to prepare a medicament with the effect of preventing and treating wheat stem base rot.

In the above use, the agent is selected from seed dressing agents.

The invention provides a compound seed dressing agent, which is compounded by a polymyxa bacillus agent and a prothioconazole agent; wherein the bacterial content of the polymyxa bacillus agent is selected from ≥5×10 ⁸ CFU/mL, and the concentration of the prothioconazole agent is selected from 30%.

The volume ratio of the above-mentioned Paenibacillus polymyxa to the prothioconazole agent is selected from 2:1 to 4:1. Preferably, the volume ratio of the Paenibacillus polymyxa to the prothioconazole agent is selected from 2:1 or 4:1.

The above-mentioned polymyxa bacillus agent can be prepared by oneself or purchased through commercial channels. Whether prepared by oneself or purchased through commercial channels, the bacterial content in the agent should meet ≥5×10 ⁸ CFU/mL. If the above-mentioned polymyxa bacillus agent is prepared by self-preparation, the technology disclosed in patent CN109497050A can be selected, or any other feasible existing technology can be used, such as patent CN113812422A.

The above-mentioned prothioconazole agent can be made by oneself or purchased through commercial channels. The concentration of prothioconazole in the agent should be 30%. If the above-mentioned prothioconazole agent is prepared by a homemade method, it can be selected from the following methods: dissolving prothioconazole in any solvent acceptable to pesticides (such as methanol, ethanol, acetone and other solvents) to prepare a prothioconazole agent with a concentration of 30%.

In practical applications, the compound seed dressing agent is selected from the following dosage: 750-900 mL of compound seed dressing agent is used for every 100 kg of wheat seeds. Preferably, the dosage of the compound seed dressing agent is: 900 mL of compound seed dressing agent is used for every 100 kg of wheat seeds; wherein the volume ratio of the polymyxa bacillus agent to the prothioconazole agent is 2:1.

The above-mentioned compound seed dressing agent has an excellent inhibitory effect on Fusarium, therefore, the above-mentioned compound seed dressing agent can be used to prevent and treat plant diseases caused by Fusarium, including but not limited to wheat stem base rot and the like.

The invention provides a novel seed dressing agent, which contains the compound seed dressing agent.

The novel seed coating agent may also contain micro-fertilizers, plant growth regulators, film-forming agents, antifreeze agents, substrate wetting agents and other adjuvants that are acceptable to seed coating.

The invention provides a comprehensive prevention and control method for wheat stem base rot, which specifically comprises: before sowing, dressing or coating wheat seeds, and then spraying a fungicide during the wheat greening period, so as to achieve comprehensive prevention and control of wheat stem base rot.

In the above-mentioned comprehensive prevention and control method, the agent used for seed dressing is selected from the above-mentioned compound seed dressing agent, and the seed coating agent used for coating is selected from the above-mentioned new seed coating agent.

In the above-mentioned integrated prevention and control method, the fungicide selected is thiophanate-methyl or propiconazole-methyl.

The beneficial effects of the present invention are:

The compound seed dressing agent of the present invention has an excellent inhibitory effect on Fusarium, and can be used to prevent and treat plant diseases such as wheat stem base rot caused by Fusarium, thereby better controlling the spread of such diseases, ensuring food production safety, and slowing down the generation of plant resistance to diseases, insects and weeds. At the same time, spraying fungicides such as thiothiocarb during the wheat greening period can effectively curb the spread of diseases, thereby forming a joint prevention with the compound seed dressing agent, improving the comprehensive prevention and control effect, and providing a basis for the future biological control of wheat stem base rot, and having broad application prospects.

DETAILED DESCRIPTION

The test materials and medicaments of the present invention are as follows:

Wheat variety: Tainong 19, one of the main local varieties, approved by Shandong Province in 2011, provided by Jinan Xinrui Seed Co., Ltd. Agent components: Bacillus polymyxa agent (≥5×10 ⁸ CFU/mL) (SC), Wuhan Kono Biotechnology Co., Ltd.; Trichoderma package (≥1×10 ⁸ spores/g) (WP), provided by the Institute of Ecology of Shandong Academy of Sciences; Prothioconazole suspension (30%) (FS), Anhui Jiuyi Agriculture Co., Ltd.; Tebuconazole (430g/L) (SC), Jiangsu Jianpai Agrochemical Co., Ltd.; Fungicide: Thifluzamide suspension (240g/L) (SC), Sichuan Runer Technology Co., Ltd. Among the above agents, SC is a suspension, WP is a wettable powder, and FS is a seed treatment suspension.

In the present invention, the structure of prothioconazole is as follows:

Other terms used in the present invention, unless otherwise specified, generally have the meanings commonly understood by those of ordinary skill in the art. The present invention is further described in detail below in conjunction with specific examples and with reference to data. The following examples are only intended to illustrate the present invention and are not intended to limit the scope of the present invention in any way.

Example

1. Field trial arrangements

The experiment was conducted on November 2, 2021 at the Seed Breeding Center of Zoucheng City, Shandong Province (35°18'N, 116°53'E). The plot has flat terrain, uniform soil fertility, good irrigation conditions, and the previous crop is corn. The base fertilizer was 50kg of compound fertilizer with N:P:K=18:20:9 per mu, the sowing rate was 12.5kg/667m ² , the row spacing was 18cm, and the sowing depth was 5cm.

2. Seed dressing with chemicals

Before sowing, take the test agent according to the dosage in Table 1, mix it with wheat and dress the seeds. After dressing, dry the seeds in a cool and ventilated place for sowing. The experiment was designed with 9 groups, each group was repeated 3 times, and each plot was ^50m2 . The control group was: no seed dressing.

Table 1

A seedling survey was conducted on December 2, 2021. Samples were taken at three diagonal points in each plot, with a total of 10 seedlings. Each treatment was repeated three times, with a total of 30 seedlings. The seedlings were taken back to the laboratory and the disease situation was recorded. At this time, the seedlings could not be graded for disease, and only the disease rate was calculated. The calculation formula is:

Diseased plant rate = (number of diseased plants/total number of plants) × 100%.

The survey results are shown in the "seedling disease rate" in Table 2. It can be seen from Table 2 that under the seed dressing conditions of the compound agent described in Group 2, wheat stem base rot was significantly controlled at the seedling stage, and the diseased plant rate was only 14.44%, which was significantly lower than that of other treatment groups and the control group. Next are Groups 3 and 4, with diseased plant rates of 28.89%, but the difference is significant compared with Group 2. The control effects of other groups are even more significant. It is worth mentioning that Bacillus polymyxa (Group 1) showed a control effect similar to that of prothioconazole (Group 8). This result is of great value for the development of new strains for the control of wheat stem base rot.

3. Spray fungicides during the green period

During the wheat greening period (March 3, 2022), 240g/L thiothiocarb suspension was sprayed in each plot at a dosage of 20mL/ ^667m2 , except for the control group.

A survey was conducted during the jointing stage on March 25, 2022. Sampling was carried out with reference to sampling during the seedling stage, and the diseased plant rate during the jointing stage was calculated.

A survey was conducted during the grain filling period on May 9, 2022 to investigate the white ear rate. The sampling method for each plot was the same as that for the seedling stage. 90 stems were sampled for each treatment and brought back to the laboratory for diseased stem grading. The grading standard was based on the Shandong Provincial Technical Specifications for Wheat Stem Rot Monitoring and Reporting. The grading standard was as follows: Level 0: The whole stem was asymptomatic; Level 1: The first leaf sheath at the base of the aboveground part turned brown, but there was no lesion on the stem node; Level 3: The first stem node of the aboveground part turned brown; Level 5: The second stem node of the aboveground part turned brown; Level 7: The brown lesions exceeded the second stem node, but there was no white ear; Level 9: The brown lesions exceeded the second stem node, resulting in white ears or no ears due to the disease; The diseased plant rate and disease index during the grain filling period were calculated. The calculation formula is:

Diseased plant rate = (number of diseased plants/total number of plants) × 100%;

Disease index = 100 × ∑ (number of diseased leaves at each level × representative value of each level) / (total number of leaves surveyed × highest representative value).

The survey results are shown in Table 2, "Jointing stage diseased plant rate", "Grain filling stage diseased stem rate", "Grain filling stage disease index" and "Control effect". As shown in Table 2, applying pesticides during the greening period effectively curbed the spread of the disease, and the diseased plant rate of each treatment in the seedling stage did not change much. The jointing stage diseased plant rate of the control group increased significantly compared with the seedling stage, with an increase of 12.22%.

Table 2

Note: The test data in Table 2 were obtained by using the Duncan's new multiple range method to perform variance analysis on the survey data of the wheat growth period with the help of the DPS (9.01) data processing system. The diseased plant rates of each group in Table 2 do not completely show a consistent change pattern. The main reason is that the experimental field is large and the sampling points in each period may not be in the same location. This sampling test error will cause fluctuations in the test data, but this fluctuation is within a reasonable range and will not affect the interpretation of the technical effect of the present invention.

The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims (4)

1. The compound seed dressing medicament is characterized by being prepared by compounding a paenibacillus polymyxa bacterial agent and a prothioconazole medicament;

The bacterial content of the paenibacillus polymyxa bacterial agent is more than or equal to 5 multiplied by 10 ⁸ CFU/mL, and the concentration of the prothioconazole bacterial agent is 30%;

The dosage of the compound seed dressing agent is as follows: 900mL of compound seed dressing agent is selected for each 100kg of wheat seeds; wherein, the volume ratio of the paenibacillus polymyxa bacterial agent to the prothioconazole bacterial agent is 2:1.

2. A novel seed coating agent, which is characterized in that the seed coating agent contains the compound seed dressing agent in claim 1.

3. The novel seed coating agent according to claim 2, wherein the seed coating agent further comprises a seed-acceptable micro-fertilizer, a plant growth regulator, a film forming agent, an antifreezing agent, a substrate wetting agent or other auxiliary agents.

4. A comprehensive control method for wheat stem rot is characterized by comprising the following specific steps: before sowing, seed dressing or coating is carried out on the wheat, and then a bactericide is sprayed in the wheat turning green period, so that the comprehensive control of the wheat stem basal rot is realized; wherein the medicament for seed dressing is the compound seed dressing medicament of claim 1; the seed coating agent used for coating is the novel seed coating agent of claim 2 or 3; the bactericide is thifluzamide or propiconazole azoxystrobin.