A kind of mongolica pine damping-off control agent and preparation method thereof

Abstract

The invention discloses a mongolica damping-off control agent and a preparation method thereof, belonging to the technical field of mongolica damping-off control. The control agent consists of gel particles and a synergist. By applying the gel particles and the synergist to soil of a mongolica planting site, the surface temperature of the mongolica planting site can be effectively reduced through synergistic action, thereby solving the problem of mongolica damping-off caused by root neck burns due to excessively high surface temperature. The control agent can also effectively prevent damping-off caused by pathogen infection, thereby greatly reducing the prevalence of mongolica damping-off and promoting the healthy growth of mongolica.

Description

Technical Field

[0001] The invention relates to the technical field of prevention and treatment of mongolica pine damping-off, and in particular to a mongolica pine damping-off prevention and treatment agent and a preparation method thereof. Background Art

[0002] Scotch pine (Pinus sylvestris var. mongholica Litv.) is a plant of the Pinaceae family, an evergreen tree, 15-25 meters high, up to 30 meters high, with an elliptical or conical crown. It is the main fast-growing timber, protective greening, and excellent tree species for soil and water conservation in Northeast China. The wood is strong and has straight texture. It can be used for construction, furniture, etc. The trunk can be tapped for resin to extract pine pear and turpentine, and the bark can be used to extract tannin, which has a wide range of uses.

[0003] Damping-off is a disease that Pinus sylvestris is easily infected with during its growth. There are two causes of damping-off: physiological and infectious. Physiological damping-off is mostly due to the direct influence of abiotic factors such as strong sunlight, dry wind, high temperature, and large soil evaporation. These abiotic factors mainly cause excessive surface temperature to burn the root neck, thus causing damping-off. Excessive surface temperature burning the root neck will cause extremely narrow depressions at a distance of 1-5 mm from the ground due to local scalding, and the aboveground part will fall off suddenly, eventually leading to the death of the seedlings. In addition, excessive surface temperature will also take away a large amount of moisture in the soil, causing the Pinus sylvestris to wilt, fall off suddenly, and die. Infectious damping-off: It is mostly caused by various damping-off bacteria in the soil infecting the neck or the upper part of the taproot, causing the phloem conducting tissue to ulcerate and rot, presenting aboveground symptoms similar to those of physiological damping-off. The pathogens are mainly Rhizoctonia, Fusarium, and Pythium. At present, the prevention and control of Larix gmelinii damping-off disease is mainly focused on infectious damping-off disease. There is less prevention and control of damping-off disease caused by excessively high surface temperature burning the root neck. In addition, the prevention and control of infectious damping-off disease mostly adopts the method of spraying pesticides, but the pesticides are easy to remain and cause toxicity to the plants.

[0004] Therefore, there is an urgent need for a control agent for Scotch pine damping-off disease and a preparation method thereof, which mainly solves the physiological causes of the disease, such as excessive surface temperature burning the root neck and bacterial infection causing Scotch pine damping-off disease, causing Scotch pine to wilt, fall off suddenly, and die. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a control agent for Scotch pine damping-off disease and a preparation method thereof, which mainly solves the physiological causes of the disease, such as excessively high surface temperature burning the root neck and bacterial infection causing Scotch pine damping-off disease, causing Scotch pine to wilt, keel over, and die.

[0006] The present invention solves the above technical problems by the following technical means:

[0007] A control agent for Scotch pine damping-off disease consists of gel particles and a synergist, wherein green trichoderma is loaded inside the gel particles.

[0008] Furthermore, the gel particles include the following raw materials in parts by weight: 8-10 parts of ammonium benzoate, 8-10 parts of ammonium iodide, 5-7 parts of barium hydroxide, 10-15 parts of ammonium nitrate, 70-80 parts of sodium alginate, and 1-2 parts of calcium gluconate.

[0009] Furthermore, the ammonium benzoate, ammonium iodide, barium hydroxide and ammonium nitrate are all in powder form.

[0010] Furthermore, the synergist comprises the following raw materials in parts by weight: 10-20 parts of menthol, 10-20 parts of menthyl amide, 5-10 parts of xylitol, 5-10 parts of potassium chloride, and 0.05-0.1 parts of green Trichoderma.

[0011] A method for preparing a control agent for Scotch pine damping-off disease, wherein the method for preparing gel particles in the control agent is as follows:

[0012] S1: Add water to sodium alginate and mix well, then heat to 60-70°C and stir for 3-5 minutes, then add calcium gluconate and stir until it becomes a gel to obtain sodium alginate gel;

[0013] S2: ammonium benzoate, ammonium iodide, barium hydroxide and ammonium nitrate are mixed evenly and put into a granulator to prepare mixed particles with a particle size of 0.3-1.5 cm;

[0014] S3: adding the mixed particles into sodium alginate gel, stirring at a speed of 600-800 r / min for 10-15 min to obtain sodium alginate gel-coated particles, and freeze-drying the sodium alginate gel-coated particles to obtain gel particles.

[0015] Furthermore, the preparation method of the synergist in the control agent is as follows:

[0016] The synergist is obtained by uniformly mixing menthol, menthyl amide, xylitol, potassium chloride and trichoderma viride.

[0017] Furthermore, in the preparation step S3 of the gel particles, the freeze-drying temperature is minus 40-minus 60° C., and the time is 28-36 hours.

[0018] Further, the method of using the control agent is as follows:

[0019] A. Turning the soil of the Pinus sylvestris var. mongolica planting area, and after turning the soil, sprinkling straw residue into the soil, raking the straw residue and the surface soil evenly, and then applying gel particles into the soil;

[0020] B. Add 75% ethanol to the enhancer to dissolve it, then add water and mix well to obtain the enhancer solution, and spray the enhancer solution on the Larix gmelinii planting area.

[0021] Due to strong sunlight, high weather temperature will cause the surface temperature of the mongolica pine planting area to be too high, burning the root neck and causing mongolica pine damping-off disease. The infection of pathogens in the soil will also cause mongolica pine to suffer from damping-off disease, causing it to wilt, fall off suddenly, and die. Applying control agents to the mongolica pine planting area can effectively prevent and control mongolica pine damping-off disease.

[0022] Apply gel particles to the planting site of Pinus sylvestris, then dissolve the enhancer to prepare an enhancer liquid and spray it on the planting site. The menthol, menthyl amine, xylitol and potassium chloride in the enhancer liquid will absorb the heat in the air around the surface, thereby reducing the surface temperature, which can effectively inhibit the damping-off disease of Pinus sylvestris caused by excessively high surface temperature. However, since menthol, menthyl amine, xylitol and potassium chloride can only temporarily reduce the surface temperature, and the sun shines for a long time in summer, the surface temperature will continue to rise during the day, and the enhancer is not enough to maintain a low surface temperature for a long time, so the soil needs to be further treated;

[0023] The gel particles applied in the soil absorb the synergistic liquid and begin to swell. The ammonium benzoate and ammonium iodide in the gel particles combine with the absorbed synergistic liquid, causing the NH bonds in the ammonium benzoate and ammonium iodide to break, absorbing heat from the surrounding air, thereby lowering the surface temperature. When the ammonium nitrate inside the gel particles encounters the absorbed synergistic liquid, it also begins to absorb heat from the surrounding air, and further reacts with barium hydroxide to increase the amount of heat absorbed, thereby more effectively and continuously lowering the surface temperature. Because ammonium benzoate, ammonium iodide, barium hydroxide, and ammonium nitrate are coated inside the gel, the synergistic liquid gradually penetrates into the particles after the gel absorbs the synergistic liquid, thereby extending the continuous action time of the internal substances, and can keep the surface temperature at a lower temperature for a longer time, thereby effectively preventing damping-off caused by excessive surface temperature burning the root neck in hot weather;

[0024] Adding green Trichoderma to the enhancer can effectively prevent damping-off caused by Rhizoctonia, Fusarium, and Pythium, and has no residual toxicity, which can promote the healthy growth of Larix gmelinii.

[0025] Furthermore, the application amount of the gel particles is 0.1-1 kg / m 2 The spraying amount of the synergistic liquid is 0.5-3kg / m 2 .

[0026] Furthermore, the control agent is applied at 12-14 o'clock.

[0027] The prepared control agent mainly solves the physiological cause of the disease, which is caused by excessively high surface temperature burning the root neck, by lowering the surface temperature. It is used between 12:00 and 14:00, which is the time period with the highest temperature in a day, and the surface temperature also reaches the highest. At this time, the control agent is applied to the soil, and part of the synergistic liquid quickly lowers the surface temperature. Then, the gel particles absorb part of the synergistic liquid and then absorb the heat of the surface temperature to keep the surface temperature at a low temperature, thereby maximizing the effect of the control agent.

[0028] Furthermore, the amount of straw residue is 0.2-2kg / m 2 .

[0029] Applying straw residue to the root soil can increase the air permeability of the root soil, improve soil conditions, promote the reproduction of green Trichoderma, enhance the prevention and control effect of green Trichoderma against pathogens, and improve the prevention and control effect.

[0030] Beneficial effects:

[0031] 1. The present invention discloses a mongolica damping-off control agent and a preparation method thereof. By applying the control agent to a mongolica planting site, the surface temperature can be effectively reduced in high temperature weather, and the problem of mongolica damping-off caused by excessively high surface temperature burning the root neck is solved. Meanwhile, green Trichoderma is added to the prepared control agent, which can effectively control the pathogens that cause infectious damping-off without drug toxicity. While solving the physiological damping-off caused by excessively high surface temperature burning the root neck, the infectious damping-off caused by pathogen infection is solved, thereby greatly reducing the prevalence of mongolica damping-off and promoting the healthy growth of mongolica.

[0032] 2. The present invention discloses that the control agent is prepared into gel particles and a synergist respectively, and the gel particles and the synergist work synergistically, which can effectively prolong the time for lowering the surface temperature and improve the control effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 : It is a picture of the growth status of 2-year-old Scots pine seedlings to which the control agent of the present invention is applied; DETAILED DESCRIPTION

[0034] The present invention will be described in detail below with reference to specific embodiments and accompanying drawings:

[0035] Example 1: Preparation of a control agent

[0036] (1) Preparation of gel particles:

[0037] 0.8 kg of ammonium benzoate, 0.8 kg of ammonium iodide, 0.5 kg of barium hydroxide, 1 kg of ammonium nitrate, and 7 kg of sodium alginate were weighed respectively, and the weighed ammonium benzoate, ammonium iodide, barium hydroxide, and ammonium nitrate were all in powder form.

[0038] Preparation method:

[0039] S1: Add 70 kg of water to sodium alginate and mix well, then heat to 60°C and stir for 3 min, then add 0.3 kg of calcium gluconate and stir until it becomes a gel to obtain sodium alginate gel;

[0040] S2: powdered ammonium benzoate, ammonium iodide, barium hydroxide and ammonium nitrate are mixed evenly and put into a granulator to prepare mixed granules with a particle size of 0.3 cm;

[0041] S3: adding the mixed particles into sodium alginate gel, stirring at 600 r / min for 10 min to obtain sodium alginate gel-coated particles, placing the sodium alginate gel-coated particles in a freeze dryer at -40°C for 28 h to obtain gel particles.

[0042] (2) Preparation of synergist:

[0043] Weigh 1 kg of menthol, 1 kg of menthyl amide, 0.5 kg of xylitol, 0.5 kg of potassium chloride, and 5 g of trichoderma viride respectively.

[0044] Preparation method:

[0045] The synergist is obtained by uniformly mixing menthol, menthyl amide, xylitol, potassium chloride and trichoderma viride.

[0046] Example 2: Preparation of control agent 2

[0047] (1) Preparation of gel particles:

[0048] 0.9 kg of ammonium benzoate, 0.9 kg of ammonium iodide, 0.6 kg of barium hydroxide, 1.2 kg of ammonium nitrate, and 7.5 kg of sodium alginate were weighed respectively, and the weighed ammonium benzoate, ammonium iodide, barium hydroxide, and ammonium nitrate were all in powder form.

[0049] Preparation method:

[0050] S1: Add 75 kg of water to sodium alginate and mix well, then heat to 65°C and stir for 4 min, then add 0.4 kg of calcium gluconate and stir until it becomes a gel to obtain sodium alginate gel;

[0051] S2: powdered ammonium benzoate, ammonium iodide, barium hydroxide and ammonium nitrate are mixed evenly and put into a granulator to prepare mixed granules with a particle size of 0.5 cm;

[0052] S3: adding the mixed particles into sodium alginate gel, stirring at 700 r / min for 13 min to obtain sodium alginate gel-coated particles, placing the sodium alginate gel-coated particles in a freeze dryer at -50°C for 32 h to obtain gel particles.

[0053] (2) Preparation of synergist:

[0054] Weigh 1.5 kg of menthol, 1.5 kg of menthyl amine, 0.8 kg of xylitol, 0.8 kg of potassium chloride, and 8 g of trichoderma viride respectively.

[0055] Preparation method:

[0056] The synergist is obtained by uniformly mixing menthol, menthyl amide, xylitol, potassium chloride and trichoderma viride.

[0057] Example 3: Preparation of control agent 3

[0058] (1) Preparation of gel particles:

[0059] 1 kg of ammonium benzoate, 1 kg of ammonium iodide, 0.7 kg of barium hydroxide, 1.5 kg of ammonium nitrate, and 8 kg of sodium alginate were weighed respectively, and the weighed ammonium benzoate, ammonium iodide, barium hydroxide, and ammonium nitrate were all in powder form.

[0060] Preparation method:

[0061] S1: Add 80 kg of water to sodium alginate and mix well, then heat to 70°C and stir for 5 min, then add 0.5 kg of calcium gluconate and stir until it becomes a gel to obtain sodium alginate gel;

[0062] S2: powdered ammonium benzoate, ammonium iodide, barium hydroxide and ammonium nitrate are mixed evenly and put into a granulator to prepare mixed granules with a particle size of 0.8 cm;

[0063] S3: adding the mixed particles into sodium alginate gel, stirring at 800 r / min for 15 min to obtain sodium alginate gel-coated particles, placing the sodium alginate gel-coated particles in a freeze dryer at -60°C for 36 h to obtain gel particles.

[0064] (2) Preparation of synergist:

[0065] Weigh 2 kg of menthol, 2 kg of menthyl amine, 1 kg of xylitol, 1 kg of potassium chloride, and 10 g of Trichoderma viride respectively.

[0066] Preparation method:

[0067] The synergist is obtained by uniformly mixing menthol, menthyl amide, xylitol, potassium chloride and trichoderma viride.

[0068] Comparative Example 1: Preparation of control agent

[0069] A comparative example is formed with Example 1, the only difference being that ammonium benzoate and ammonium iodide are not added to the gel particles during the preparation of the control agent.

[0070] (1) Preparation of gel particles:

[0071] 0.5 g of barium hydroxide, 1 kg of ammonium nitrate, and 7 kg of sodium alginate were weighed respectively, and the weighed barium hydroxide and ammonium nitrate were both in powder form.

[0072] Preparation method:

[0073] S1: Add 70 kg of water to sodium alginate and mix well, then heat to 60°C and stir for 3 min, then add 0.3 kg of calcium gluconate and stir until it becomes a gel to obtain sodium alginate gel;

[0074] S2: Powdered barium hydroxide and ammonium nitrate are mixed evenly and put into a granulator to prepare mixed particles with a particle size of 0.3 cm;

[0075] S3: adding the mixed particles into sodium alginate gel, stirring at 600 r / min for 10 min to obtain sodium alginate gel-coated particles, placing the sodium alginate gel-coated particles in a freeze dryer at -40°C for 28 h to obtain gel particles.

[0076] (2) Preparation of synergist: Same as Example 1.

[0077] Comparative Example 2: Preparation of control agent

[0078] A comparative example is formed with Example 1, the only difference being that barium hydroxide and ammonium nitrate are not added to the gel particles during the preparation of the control agent.

[0079] (1) Preparation of gel particles:

[0080] 0.8 kg of ammonium benzoate, 0.8 kg of ammonium iodide and 7 kg of sodium alginate were weighed respectively, and the weighed ammonium benzoate and ammonium iodide were both in powder form.

[0081] Preparation method:

[0082] S1: Add 70 kg of water to sodium alginate and mix well, then heat to 60°C and stir for 3 min, then add 0.3 kg of calcium gluconate and stir until it becomes a gel to obtain sodium alginate gel;

[0083] S2: powdered ammonium benzoate and ammonium iodide are mixed evenly and put into a granulator to prepare mixed granules with a particle size of 0.3 cm;

[0084] S3: adding the mixed particles into sodium alginate gel, stirring at 600 r / min for 10 min to obtain sodium alginate gel-coated particles, placing the sodium alginate gel-coated particles in a freeze dryer at -40°C for 28 h to obtain gel particles.

[0085] (2) Preparation of synergist: Same as Example 1.

[0086] Comparative Example 3: Preparation of control agent

[0087] A comparative example is formed with Example 1, the only difference being that sodium alginate gel is used for coating during the preparation of the control agent, and ammonium benzoate, ammonium iodide, barium hydroxide and ammonium nitrate are directly mixed evenly and then placed in a granulator to prepare granules.

[0088] (1) Particle preparation:

[0089] 0.8 kg of ammonium benzoate, 0.8 kg of ammonium iodide, 0.5 g of barium hydroxide, and 1 kg of ammonium nitrate were weighed respectively, and the weighed ammonium benzoate, ammonium iodide, barium hydroxide, and ammonium nitrate were all in powder form.

[0090] Preparation method:

[0091] S1: powdered ammonium benzoate, ammonium iodide, barium hydroxide and ammonium nitrate are mixed evenly and placed in a granulator to prepare mixed particles with a particle size of 0.3 cm;

[0092] (2) Preparation of synergist: Same as Example 1.

[0093] Comparative Example 4: Preparation of control agent

[0094] A comparative example is formed with Example 1, the only difference being that no viride is added to the synergist when the control agent is prepared.

[0095] (1) Preparation of gel particles: the same as in Example 1;

[0096] (2) Preparation of synergist:

[0097] Weigh 1 kg of menthol, 1 kg of menthyl amide, 0.5 kg of xylitol, and 0.5 kg of potassium chloride respectively.

[0098] Preparation method:

[0099] The synergist is obtained by uniformly mixing menthol, menthyl amide, xylitol and potassium chloride.

[0100] Comparative Example 5: Preparation of control agent

[0101] A comparative example is formed with Example 1, except that no menthol, menthyl amine, xylitol or potassium chloride is added to the synergist when the control agent is prepared.

[0102] (1) Preparation of gel particles: the same as in Example 1;

[0103] (2) Preparation of synergist: Weigh 5 g of Trichoderma viride to obtain the synergist.

[0104] Example 4: Method of using the control agent

[0105] In mid-June, two-year-old Pinus sylvestris var. mongolica from a Pinus sylvestris var. mongolica plantation in Niujialiang Forest Farm, Yuyang District, Yulin City, Shaanxi Province was selected for prevention and treatment of Pinus sylvestris var. mongolica damping-off disease. Example 4 selected the control agent prepared in Example 1.

[0106] A. Use a hoe to turn the soil in the field where Pinus sylvestris is planted. The thickness of the soil turning is about 20 cm. After the soil turning is completed, the soil is turned at a rate of 0.5 kg / m 2 The straw residue was sprinkled into the soil, the straw residue and the surface soil were raked evenly, and then the gel particles prepared in Example 1 were applied to the soil at an application rate of 0.2 kg / m 2 ;

[0107] B. Weigh 500 g of the synergist prepared in Example 1, add 2 times the weight of 75% ethanol to the synergist and stir evenly, then add 50 times the weight of clean water and mix evenly to obtain a synergist solution, and dilute at 1 kg / m 2 The synergistic liquid is sprayed on the Pinus sylvestris var. mongolica planting area at a spraying rate of.

[0108] Comparative Example 6: Method of using the control agent

[0109] A comparative example is formed with Example 4, the only difference being that straw residue is not applied to the soil when the control agent is used.

[0110] A. Use a hoe to turn the soil in the field where Pinus sylvestris is planted. The thickness of the soil turning is about 20 cm. After the soil turning is completed, the soil is turned at a rate of 0.3 kg / m 2 Applying the gel particles prepared in Example 1 to the soil in an amount of;

[0111] B. Weigh 500 g of the synergist prepared in Example 1, add 2 times the weight of 75% ethanol to the synergist and stir evenly, then add 50 times the weight of clean water and mix evenly to obtain a synergist solution, and dilute at 1 kg / m 2 Spray the synergistic liquid on the Pinus sylvestris var. mongolica planting area at a spraying rate of

[0112] Comparative Example 7: Method of using the control agent

[0113] A comparative example is formed with Example 4, the only difference being that after the gel particles are applied, no synergist is sprayed, but clean water is sprayed directly.

[0114] A. Use a hoe to turn the soil in the field where Pinus sylvestris is planted. The thickness of the soil turning is about 20 cm. After the soil turning is completed, the soil is turned at a rate of 0.5 kg / m 2The straw residue was sprinkled into the soil, the straw residue and the surface soil were raked evenly, and then the gel particles prepared in Example 1 were applied to the soil at an application rate of 0.3 kg / m 2 ;

[0115] B. According to 1kg / m 2 The spraying amount of water was sprayed on the Pinus sylvestris var. mongolica planting field after applying the gel particles.

[0116] Blank control:

[0117] A. Use a hoe to turn the soil in the field where Pinus sylvestris is planted. The thickness of the soil turning is about 20 cm. After the soil turning is completed, the soil is turned at a rate of 0.5 kg / m 2 Sprinkle the straw residue with the surface soil, rake the straw residue and the surface soil evenly, and then apply clean water to the soil at an application rate of 0.3kg / m 2 ;

[0118] B. Spray clean water on the planting area of ​​Pinus sylvestris var. mongolica with a spraying amount of 1kg / m 2 .

[0119] Experiment: Prevention and control of Pinus sylvestris blight

[0120] 1. In mid-June, an experiment was conducted at a pine plantation in Niujialiang Forest Farm, Yuyang District, Yulin City, Shaanxi Province. A 2-year-old pine plantation was selected as an experimental plant. The soil in the experimental site was fertile, loose, and well-drained. The altitude was about 1000 meters, the pH value was 6-7, the annual average temperature was 10°C, the frost-free period was 159 days, the average sunshine was 2793.5h, the annual average rainfall was 400 mm, and the management capacity in the base was relatively high. The control agent prepared in Example 1 and Comparative Examples 1-5 was subjected to a pine damping-off disease control experiment. The experiment was divided into 9 groups: experimental group 1, control group 1-7, and blank control group, each group had 20 trees, and 3 replicates. The control agent was used when the temperature was higher than 35°C at 13:00 noon in the day, and no control agent was needed when the temperature was lower than 35°C.

[0121] 2. Control agent

[0122] Experimental group 1: the control agent prepared in Example 1 was used;

[0123] Control groups 1-5: the control agents prepared in comparative examples 1-5 were respectively selected;

[0124] Control group 6-7: the control agent prepared in Example 1 was selected;

[0125] Blank control group: clean water was used as the control.

[0126] 3. Prevention and control methods of Pinus sylvestris blight

[0127] Experimental group 1: The control agent of Example 4 was used to control the damping-off disease of Pinus sylvestris var. mongolica;

[0128] Control group 1-5: the control agent of Example 4 was used to control Pinus sylvestris damping-off disease;

[0129] Control groups 6-7: The control methods of control agents in comparative examples 6-7 were respectively used to carry out control experiments on Pinus sylvestris damping-off;

[0130] Blank control group: A blank control group method was used to form a comparison with the above experimental group and control group.

[0131] 4. Detection of cooling frequency and cooling duration: Thermometers were inserted into the soil in the plant area of ​​experimental group 1, control group 1-7, and blank control group to measure the surface temperature, with an insertion depth of 1.5 cm. Then, the control agent was applied at 12 noon. The surface temperature of the soil in each group was detected 10 minutes after the control agent was applied, and then the cooling frequency of each group was calculated, cooling frequency = (soil surface temperature without control agent application - soil surface temperature with control agent application); the surface temperature of each group was continuously monitored to record the cooling duration of the control agent (when the soil surface temperature with control agent application is consistent with the soil surface temperature without control agent application, it indicates that the control effect of the control agent is over, and the period from the beginning of control agent application to the end of control effect is the cooling duration. The experiment was repeated 3 times, and the average data of the cooling frequency and cooling duration of each group are shown in Table 1:

[0132] Table 1

[0133]

[0134]

[0135] Disease rate = (number of diseased trees / total number of trees) × 100%.

[0136] Disease judgment criteria:

[0137] Damping-off caused by excessively high surface temperature burning the root neck: the root of the seedling is 1-5mm from the ground, and a very narrow depression occurs due to local burns, and the above-ground part falls off suddenly;

[0138] Damping-off disease caused by bacterial infection: the part of the rhizome close to the ground initially appears waterlogged, then turns yellow-brown, shrinks and falls off suddenly, and the stems and leaves above ground appear gray-green and wilted.

[0139] The average data of the prevalence of each group are shown in Table 2:

[0140] Table 2

[0141]

[0142] According to the data analysis in Table 1:

[0143] (1) Compared with control groups 1-7 and the blank control group, the temperature reduction index of experimental group 1 was significantly higher than that of control groups 1-7 and the blank control group. Among the control groups, the temperature reduction index difference between control group 7 and experimental group 1 was the largest. This was because the control group 7 used a synergist when controlling damping-off disease, resulting in less heat absorbed after the control agent was applied, resulting in a decrease in the degree of reduction in the ground surface temperature. This shows that the synergistic effect of the gel particles and the synergist can more effectively exert the cooling effect of the control agent and effectively reduce the ground surface temperature.

[0144] (2) Compared with control groups 1-7 and the blank control group, the cooling time of experimental group 1 was significantly longer than that of control groups 1-7 and the blank control group. Among the control groups, the difference in cooling time between control group 3 and experimental group 1 was the largest. This was because the control agents in control group 3 were not coated with gel, and ammonium benzoate, ammonium iodide, barium hydroxide, and ammonium nitrate became ineffective after rapid action, resulting in a shortened cooling time. This indicates that coating the particles of ammonium benzoate, ammonium iodide, barium hydroxide, and ammonium nitrate with gel can increase the action time of the particles, thereby extending the time to reduce the surface temperature.

[0145] According to the data analysis in Table 2:

[0146] (3) Compared with experimental group 1, the prevalence of control group 1 increased by 5%. This was because ammonium benzoate and ammonium iodide were not added to the gel particles of the control agent in control group 1, and they failed to combine with the synergistic liquid to absorb the heat in the surrounding air, resulting in a small reduction in the surface temperature. Therefore, the high surface temperature increased the prevalence of Pinus sylvestris blight.

[0147] (4) Compared with experimental group 1, the prevalence of control group 2 increased by 6.7%. This was because barium hydroxide and ammonium nitrate were not added to the gel particles in the control agent preparation of control group 2, resulting in the failure of ammonium nitrate to combine with the synergistic liquid to absorb the heat in the surrounding air, and did not react with barium hydroxide to increase the amount of heat absorbed, resulting in excessively high surface temperature and an increase in the prevalence of Scots pine blight;

[0148] (5) Compared with experimental group 1, the prevalence of control group 3 increased by 5%. This was because sodium alginate gel was not added to the control agent in control group 3 for coating to form gel-coated particles, which resulted in ammonium benzoate, ammonium iodide, barium hydroxide, and ammonium nitrate failing to act quickly and failing to continuously reduce the surface temperature, causing the surface temperature of the Pinus sylvestris planting area to be too high for a long time, resulting in an increase in the prevalence of Pinus sylvestris blight.

[0149] (6) The morbidity of control group 4 increased by 6.7% compared with experimental group 1. This was because no green Trichoderma was added to the synergist when the control agent was prepared in control group 4, resulting in the failure to effectively inhibit the pathogens in the soil, which caused the infectious damping-off disease of Pinus sylvestris var. mongolica, leading to an increase in the morbidity of damping-off disease of Pinus sylvestris var. mongolica.

[0150] (7) Compared with experimental group 1, the disease rate of control group 5 increased by 6.7%. This was because menthol, menthyl amine, xylitol, and potassium chloride were not added to the synergist when the control agent was prepared in control group 5, which reduced the amount of heat absorbed by the surrounding environment on the surface, resulting in a smaller decrease in the surface temperature, making the surface temperature of the mongolica planting area too high, and increasing the disease rate of damping-off disease;

[0151] (8) The prevalence of the disease in control group 6 increased by 5% compared with that in experimental group 1. This was because in control group 6, straw residue was not added to the soil in the planting area during the prevention and control of Scots pine damping-off, which reduced the air permeability of the soil and reduced the effect of the control agent, resulting in an increase in the prevalence of Scots pine damping-off.

[0152] (9) The prevalence of the control group 7 increased by 3.4% compared with the experimental group 1. In the control group 7, the synergistic liquid was replaced with clean water and sprayed evenly on the soil of the planting area, so that the gel particles in the soil around the roots of Pinus sylvestris absorbed the clean water but failed to absorb the synergistic liquid, resulting in a decrease in the effect and an increase in the prevalence of Pinus sylvestris damping-off disease.

[0153] (10) Compared with control groups 1-7 and the blank control, the morbidity of experimental group 1 was significantly lower than that of control groups 1-7 and the blank control group, indicating that applying straw residue and control agents to the soil can effectively improve soil permeability and reduce surface temperature, solve the problem of damping-off disease of Larix gmelinii caused by soil compaction, poor permeability and high surface temperature that burns the rhizomes, and effectively prevent infectious damping-off disease caused by pathogens such as Fusarium, reduce the morbidity of Larix gmelinii damping-off disease, and promote the healthy growth of Larix gmelinii.

[0154] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, which should be included in the scope of the claims of the present invention. The techniques, shapes, and structural parts not described in detail in the present invention are all known technologies.

Claims

1. A control agent for Pinus sylvestris damping-off disease, characterized in that The control agent is composed of gel particles and a synergist, and the interior of the gel particles is loaded with viride; The gel particles include the following raw materials in parts by weight: 8-10 parts of ammonium benzoate, 8-10 parts of ammonium iodide, 5-7 parts of barium hydroxide, 10-15 parts of ammonium nitrate, 70-80 parts of sodium alginate, and 3-5 parts of calcium gluconate; The synergist comprises the following raw materials in parts by weight: 10-20 parts of menthol, 10-20 parts of menthyl amide, 5-10 parts of xylitol, 5-10 parts of potassium chloride, and 0.05-0.1 parts of green Trichoderma; The method of using the control agent is as follows: A. Turning the soil of the Pinus sylvestris var. mongolica planting area, and after turning the soil, sprinkle straw residue into the soil, rake the straw residue and the surface soil evenly, and then evenly apply gel particles into the soil; B. Add 75% ethanol to the enhancer to dissolve it, then add water and mix evenly to obtain the enhancer solution, and spray the enhancer solution on the planting area of ​​Pinus sylvestris var. mongolica; The application amount of the gel particles is 0.1-1 kg / m 2 The spraying amount of the synergistic liquid is 0.5-3kg / m 2 ; The application time of the control agent is 12-14 o'clock.

2. A method for preparing a control agent for Scotch pine damping-off disease, characterized in that: The preparation method of the gel particles in the control agent is as follows: S1: Add water to sodium alginate and mix well, then heat to 60-70°C and stir for 3-5 minutes, then add calcium gluconate and stir until it becomes a gel to obtain sodium alginate gel; S2: mixing ammonium benzoate, ammonium iodide, barium hydroxide and ammonium nitrate uniformly and putting them into a granulator to prepare mixed granules; S3: adding the mixed particles into sodium alginate gel, stirring at a speed of 600-800 r / min for 10-15 min to obtain sodium alginate gel-coated particles, and freeze-drying the sodium alginate gel-coated particles to obtain gel particles.

3. The method for preparing a Scotch pine damping-off control agent according to claim 2, characterized in that: The preparation method of the synergist in the control agent is as follows: The synergist is obtained by uniformly mixing menthol, menthyl amide, xylitol, potassium chloride and trichoderma viride.

4. The method for preparing a Scotch pine damping-off control agent according to claim 3, characterized in that: In the preparation step S3 of the gel particles, the freeze-drying temperature is minus 40-minus 60° C. and the time is 28-36 hours.

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