Cabbage seedling raising method suitable for planting of automatic seedling taking transplanter

Abstract

The invention discloses a cabbage seedling raising method suitable for planting of an automatic seedling taking transplanter, and belongs to the technical field of cabbage seedling raising. (2) sowing; (3) seedling emergence stage; (4) seedling raising period; (5) high seedling treatment; (6) growing period; and (7) a seedling hardening stage. The seedling raising method disclosed by the invention can solve the problems that seedlings emerge irregularly, the plant height and stem diameter are unreasonable, the seedling hardening time is long, and the cabbage seedlings suitable for transplanting by an automatic seedling taking transplanter are difficult to cultivate in the conventional plug cultivation of the cabbage seedlings.

Description

Technical Field

[0001] The invention relates to the technical field of cabbage seedling cultivation, and in particular to a cabbage seedling cultivation method suitable for planting by an automatic seedling transplanting machine. Background Art

[0002] Cabbage is rich in nutrients and easy to cultivate in the open field on a large scale. It is one of the important vegetables for my country's vegetable supply and export, with an annual planting area of ​​about 900,000 hectares. With the changes in planting structure and consumers' recognition of its nutritional value, the cultivation area continues to expand; the scale of planting has changed from scattered transplanting by farmers to intensive, specialized, and base-based production. In particular, the rapid development of base-based production has led to an increasing demand for efficient, light and simple cultivation technology. Transplanting is the most important link in cabbage production, and its labor force accounts for about 30% of the total labor force. Although there are many transplanting machines in production, the application rate is less than 20%. One of the main reasons is that the seedlings cultivated by the existing seedling raising technology do not meet the requirements of automatic seedling transplanting, with a low success rate of seedling removal and a high seedling damage rate, which does not meet the requirements of automatic seedling transplanting. At present, cabbage transplanted by transplanting machine usually adopts plug tray seedling cultivation to cultivate cabbage seedlings, and the automatic seedling transplanting machine directly clamps the root and stem of the cabbage seedlings to take the seedlings out of the plug tray. However, although the cabbage seedlings cultivated by the ordinary plug tray seedling cultivation method have a high germination rate, the seedlings are uneven, easy to grow too tall, and the seedlings take a long time to squat, which is easy to damage the seedlings during the machine transplanting process. Therefore, the seedlings cultivated directly by the ordinary plug tray seedling cultivation method are not conducive to mechanical transplanting. Therefore, a new cabbage seedling cultivation method suitable for machine transplanting should be provided. Summary of the invention

[0003] In view of this, the purpose of the present invention is to provide a cabbage seedling raising method suitable for planting by an automatic seedling transplanter, so as to solve the problems of uneven seedling emergence, unreasonable plant height and stem thickness, long seedling squatting time, and difficulty in cultivating cabbage seedlings suitable for transplanting by a transplanter in the current plug tray cultivation of cabbage seedlings.

[0004] The present invention solves the above problems through the following solutions:

[0005] A method for raising cabbage seedlings suitable for planting by an automatic seedling transplanter, the method for raising seedlings is as follows:

[0006] (1) Plug tray and disinfection: After disinfecting the hard plug tray, put the seedling medium into the hole;

[0007] (2) Sowing: After adjusting the humidity of the seedling medium, sow the sterilized seeds in the center of the hole;

[0008] (3) Seedling stage: After sowing, the seeds are germinated in a dark place, the daytime temperature is maintained at 23-27°C, the nighttime temperature is maintained at 20-24°C, and the relative humidity of the air and substrate is maintained at 85-95%. Germination is continued until the cotyledons emerge from the soil;

[0009] (4) Seedling stage: maintain daytime temperature at 20-24°C, nighttime temperature at 14-18°C, relative humidity of air and substrate at 60-70%, and provide appropriate shade until the cotyledons are fully extended;

[0010] (5) High seedling treatment: After the cotyledons have expanded to two leaves and one heart, shade is applied, the daytime temperature is 25-27°C, the nighttime temperature is 18-20°C, the relative humidity of the air and substrate is 80-85%, and the seedling height treatment is carried out at the same time. The high seedling treatment time is 2-4 days. After the high seedling treatment is completed, the plant ash substrate is added again;

[0011] (6) Growth period: After the high seedling treatment, the daytime temperature is controlled at 25-27°C and the nighttime temperature is controlled at 14-15°C. The relative humidity of the air and substrate is 65-70%. The light intensity is increased and water-soluble fertilizer is added.

[0012] (7) Hardening period: The temperature is maintained at 16-20°C during the day and 10-14°C at night. The relative humidity of the air and substrate is maintained at 50-55%. After 3-5 days of hardening, the cabbage seedlings suitable for planting by the automatic seedling transplanter are obtained.

[0013] Since the cabbage seedlings prepared by the present invention need to be suitable for an automatic seedling picking and transplanting machine, it is different from ordinary cabbage seedling cultivation. It is necessary to ensure that the seedlings are neat, tall, and thick in order to reduce damage when the transplanter clamps them. Therefore, the present invention strictly controls the temperature, humidity, and light conditions in the seedling cultivation process and performs high seedling treatment at the same time.

[0014] Furthermore, when cultivating older cabbage seedlings that are more than 30 days old, a 98- or 105-hole plug tray is used; when cultivating younger cabbage seedlings that are less than 30 days old, a 128- or 200-hole plug tray is used.

[0015] Cabbage seedlings with different cultivation times need to select plug trays with different holes to facilitate management and transplanting machines.

[0016] Furthermore, the seedling medium is mixed according to a mass ratio of perlite: peat soil: mushroom residue of 1:1:2, and before use, 2 kg of compound fertilizer is added to each cubic meter of the seedling medium.

[0017] Before raising seedlings, sufficient nutrients need to be added to the substrate to facilitate the growth of the seedlings.

[0018] Furthermore, in step (5), the high seedling treatment is to first spray the cabbage seedlings with a brassinolide solution, and then spray the cabbage seedlings with a high seedling treatment agent 1-2 days after the spraying, and add a wood ash matrix 1-2 days after the spraying of the high seedling treatment agent.

[0019] The high seedling treatment of the present invention is to treat the cabbage seedlings in the two-leaf and one-heart period. Brassinolide is first used in combination with light and temperature to accelerate the elongation of the cabbage seedling stems, which can quickly accelerate the height of the cabbage seedlings at this stage. However, if the treatment is carried out for a long time, it will cause the cabbage seedlings to grow too tall. Therefore, the high seedling treatment time should be strictly controlled and used in combination with a high seedling treatment agent, so as to increase the stem height and the stem thickness at the same time, thereby promoting the healthy growth of the seedlings.

[0020] Furthermore, the concentration of the brassinolide solution is 0.02-0.025 wt %, the amount of the brassinolide solution used is 1 ml / well, and the amount of the high seedling treatment agent used is 2 ml / well. The concentration and amount of the brassinolide and high seedling treatment agent should be strictly controlled.

[0021] Further, in step (5), after the high seedling treatment is completed, the specific operation of adding the plant ash matrix treatment is as follows:

[0022] After the tall seedling treatment, sprinkle a 0.5-1 cm layer of wood ash matrix mixed with wood ash and seedling medium in a mass ratio of 0.5: (1-2), and then water the mixture.

[0023] Furthermore, in step (5), the raw materials of the high seedling treatment agent include:

[0024] Betaine, urea, choline chloride, magnesium hydroxide, hydrolyzed gelatin, tannic acid and chitosan.

[0025] Furthermore, the mass ratio of chitosan, tannic acid, magnesium hydroxide, betaine, choline chloride, urea and hydrolyzed gelatin is (3-4):1:(0.3-0.5):(0.1-0.2):(1.2-1.3):1:0.5.

[0026] Further, the preparation method of the high seedling treatment agent is as follows:

[0027] (1) adding magnesium hydroxide to a 2-3 wt% tannic acid solution, stirring for 1-2 hours and then standing overnight, then adding 3-4 wt% chitosan solution and betaine, stirring evenly to obtain a mixed hydrogel;

[0028] (2) After mixing choline chloride and urea, heat them in a water bath to 80° C., stir and react for 60 minutes, cool and add 10-15 wt % hydrolyzed gelatin solution, stir evenly and add the mixed hydrogel, heat them in a water bath to 40-45° C., stir at high speed for 15-20 minutes, and let stand to obtain a high seedling treatment agent.

[0029] Furthermore, the high seedling treatment agent is diluted 3-5 times before use.

[0030] During the high seedling treatment, the first step is to use the plant endogenous hormone brassinolide to spray the cabbage seedlings with two leaves and one heart to accelerate the elongation of the stem. Since the promotion effect of brassinolide is strong, the growth rate of the cabbage seedlings is too fast at this stage. In order to inhibit this rapid growth, it is necessary to add the high seedling treatment agent immediately after the brassinolide treatment for 1-2 days to slow down the rapid absorption rate of brassinolide by the seedlings, inhibit the high concentration stimulation of brassinolide on stem growth, and then change it to a slow and continuous effect. After 1-2 days of treatment, it is cultivated normally to return to a normal growth state, and then the seedling hardening treatment is carried out. Therefore, the high seedling treatment agent of the present invention needs to first adsorb brassinolide and then release it slowly.

[0031] The chitosan of the high seedling treatment agent contains a large amount of active groups that can form a gel with excellent release performance and suitable strength, but it does not possess the autonomous drug absorption function. If chitosan is directly mixed with tannic acid, its molecular chain will usually be instantly combined with the gel forming clusters or floccules, causing its chemical properties to be unstable, and more easily causing the sudden release of medicine. Therefore, the present invention selects magnesium hydroxide particles to carry out electrical neutralization reaction adsorption of tannic acid in tannic acid solution, and then makes mixed hydrogel with chitosan and betaine. The ionic liquid formed by choline chloride and urea in the high seedling treatment agent has a wide range of solubility characteristics, can adsorb residual brassinolide, prevent the continuous high concentration of brassinolide from acting on seedlings, and the ionic liquid can release the tannic acid adsorbed by magnesium hydroxide at the same time, prompting tannic acid and chitosan to slowly self-assemble to form a thicker liquid high seedling treatment agent, reaching the purpose of adsorption-release brassinolide. In addition, direct contact of ionic liquid with seedlings will damage the epidermis of the seedlings. Therefore, it is combined with hydrolyzed gelatin to form a viscous liquid. In addition to being able to better mix with the mixed hydrogel, it can also reduce the concentration of the ionic liquid and prevent direct contact with the seedlings, thereby achieving the purpose of both quickly adsorbing brassinolide and preventing damage to the seedlings.

[0032] Therefore, when the high seedling treatment agent is applied to the cabbage seedlings, the brassinolide that has not been absorbed on the surface of the cabbage is quickly absorbed and enriched, preventing the brassinolide from continuously stimulating the seedlings at a high concentration for a long time, causing leggy growth and damaging the health of the seedlings. At the same time, the brassinolide is slowly released under the action of the gel, slowly acting on the seedlings to make them continue to elongate. After the high seedling treatment, a certain amount of plant ash needs to be spread and then watered to dissolve the alkaline substances in the plant ash and react with the high seedling treatment agent to completely stop stimulating the seedlings, so that they can grow and develop normally during the growth period and the hardening period.

[0033] Beneficial effects:

[0034] The present invention cultivates cabbage seedlings for automatic seedling transplanting machines by using a high seedling treatment agent and strictly controlling the temperature, humidity and light conditions during the seedling cultivation process. The cultivated seedlings have the advantages of plant height, thick stems and high survival rate, are suitable for machine planting, and contribute to the expansion of the cabbage industry and the development of mechanized agriculture. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 :Seedling raising process diagram;

[0036] Figure 2 : Cabbage seedlings in the growth period were cultivated in the water control (left) and experimental group (right);

[0037] Figure 3 : Transplanter transplants cabbage seedlings. DETAILED DESCRIPTION

[0038] The present invention will be described in detail below with reference to specific embodiments and accompanying drawings:

[0039] Unless otherwise specified, the experimental methods used in the examples of the present invention are all conventional methods. The materials, reagents, etc. used in the examples of the present invention, unless otherwise specified, can be obtained from commercial channels.

[0040] Embodiment 1:

[0041] Weigh the raw materials according to the following mass:

[0042] 3g chitosan (deacetylation degree 80%), 1g tannic acid, 0.3g magnesium hydroxide powder (particle size about 0.5 micron), 0.1g betaine, 1.2g choline chloride, 1g urea, 0.5g hydrolyzed gelatin.

[0043] (1) adding tannic acid to water to prepare a 2 wt % tannic acid solution, adding magnesium hydroxide powder, stirring for 1 hour and then standing overnight; then adding a 3 wt % chitosan solution prepared by chitosan and 1 wt % acetic acid solution and betaine, stirring evenly to obtain a mixed hydrogel;

[0044] (2) After mixing choline chloride and urea, heat them in a water bath to 80°C, stir and react for 60 minutes, cool and add 10 wt% hydrolyzed gelatin solution, stir evenly and add the mixed hydrogel, heat them in a water bath to 40°C and stir at high speed for 15 minutes, and let stand overnight.

[0045] Embodiment 2:

[0046] Weigh the raw materials according to the following mass:

[0047] 3.5g chitosan (deacetylation degree 80%), 1g tannic acid, 0.4g magnesium hydroxide powder (particle size about 0.5 micron), 0.15g betaine, 1.2g choline chloride, 1g urea, 0.5g hydrolyzed gelatin.

[0048] (1) adding water to tannic acid to prepare a 2.5 wt% tannic acid solution, adding magnesium hydroxide powder, stirring for 1.5 hours and then standing overnight; then adding a 3.5 wt% chitosan solution prepared by chitosan and 1 wt% acetic acid solution and betaine, stirring evenly to obtain a mixed hydrogel;

[0049] (2) After mixing choline chloride and urea, heat them in a water bath to 80°C, stir and react for 60 minutes, cool and add 12 wt% hydrolyzed gelatin solution, stir evenly and add the mixed hydrogel, heat them in a water bath to 45°C and stir at high speed for 20 minutes, and let stand overnight.

[0050] Embodiment 3:

[0051] Weigh the raw materials according to the following mass:

[0052] 4g chitosan (deacetylation degree 80%), 1g tannic acid, 0.5g magnesium hydroxide powder (particle size about 0.5 micron), 0.2g betaine, 1.3g choline chloride, 1g urea, 0.5g hydrolyzed gelatin.

[0053] (1) adding tannic acid to water to prepare a 3 wt % tannic acid solution, adding magnesium hydroxide powder, stirring for 2 hours and then standing overnight; then adding a 4 wt % chitosan solution prepared by chitosan and 1 wt % acetic acid solution and betaine, stirring evenly to obtain a mixed hydrogel;

[0054] (2) After mixing choline chloride and urea, heat them in a water bath to 80°C, stir and react for 60 minutes, cool and add 15wt% hydrolyzed gelatin solution, stir evenly and add the mixed hydrogel, heat them in a water bath to 45°C and stir at high speed for 20 minutes, and let stand overnight to treat the seedlings.

[0055] Comparative Example 1:

[0056] The high seedling treatment agent prepared in this comparative example is in contrast to Example 1, the difference being that magnesium hydroxide treatment is not used in step (1), and the specific operation is as follows:

[0057] (1) adding tannic acid to water to prepare a 2 wt % tannic acid solution, and mixing chitosan and 1 wt % acetic acid solution to prepare a 3 wt % chitosan solution, and betaine, and stirring evenly to obtain a mixed hydrogel;

[0058] The subsequent preparation steps are the same.

[0059] Comparative Example 2:

[0060] The high seedling treatment agent prepared in this comparative example is in contrast to Example 1, the difference being that tannic acid is not added in step (1), and a certain amount of cross-linking agent is added. The specific operation process is as follows:

[0061] (1) adding 0.1 g of ethylene glycol dimethacrylate (EGDMA) to a 3.5 wt % chitosan solution prepared from chitosan and 1 wt % acetic acid solution and betaine for cross-linking, and stirring to obtain a mixed hydrogel;

[0062] The subsequent preparation steps are the same.

[0063] Comparative Example 3:

[0064] The high seedling treatment agent prepared in this comparative example is in contrast to Example 1, the difference being that choline chloride and urea are not added in step (2). The specific operation process is as follows:

[0065] (2) 12 wt% hydrolyzed gelatin solution was mixed with the mixed hydrogel, heated to 45° C. in a water bath, stirred at high speed for 20 min, and allowed to stand overnight to form a seedling treatment agent.

[0066] Comparative Example 4:

[0067] The high seedling treatment agent prepared in this comparative example is in contrast to Example 1, the difference being that hydrolyzed gelatin is not added in step (2). The specific operation process is as follows:

[0068] (2) After mixing choline chloride and urea, heat them in a water bath to 80°C, stir and react for 60 minutes, cool them, add the mixed hydrogel, heat them in a water bath to 45°C, stir them at high speed for 20 minutes, and let them stand overnight.

[0069] Comparative Example 5:

[0070] The high seedling treatment agent prepared in this comparative example is compared with Example 1, the difference being that in step (1), the mass ratio of the raw materials chitosan to tannic acid is increased to 5:1, the specific amount of chitosan used is 5 g, and the amount of tannic acid is 1 g, and the rest of the process remains unchanged.

[0071] Comparative Example 6:

[0072] The high seedling treatment agent prepared in this comparative example is in contrast to Example 1, the difference being that the preparation method of the high seedling treatment agent is as follows:

[0073] Mix choline chloride and urea, heat in a water bath to 80°C, stir and react for 60 minutes, cool, add 3wt% chitosan solution made of chitosan and 1wt% acetic acid solution, stir evenly, add tannic acid and water to make 2wt% tannic acid solution, heat in a water bath to 40°C, stir at high speed for 15 minutes, and let stand overnight.

[0074] Embodiment 4:

[0075] (1) Plug tray and disinfection: After disinfecting the hard plug tray, put the seedling medium into the hole;

[0076] The seedling medium is mixed in a mass ratio of 1:1:2 between perlite, peat soil and mushroom residue. The pH value can be adjusted to 6.0-6.5. After mixing, 2kg of compound fertilizer for seedlings is added to each cubic meter of the seedling medium. After stirring evenly, add it to the plug tray to fill the plug tray.

[0077] When growing older cabbage seedlings over 30 days old, use a 98- or 105-hole tray; when growing younger cabbage seedlings under 30 days old, use a 128- or 200-hole tray.

[0078] (2) Sowing: After adjusting the humidity of the seedling medium, sow the sterilized seeds in the plug tray until they can be folded into a ball, with one seedling per hole;

[0079] (3) Seedling stage: After sowing, the seeds are germinated in a dark place, the daytime temperature is maintained at 23-27°C, the nighttime temperature is maintained at 20-24°C, and the relative humidity of the air and substrate is maintained at 85-95%. Germination is continued until the cotyledons emerge from the soil, which is usually about 2-3 days.

[0080] (4) Seedling stage: maintain daytime temperature at 20-24°C, nighttime temperature at 14-18°C, relative humidity of air and substrate at 60-70%, shading rate at 30-35%, photoperiod at 13-14h, until cotyledons are fully extended, usually for 3-4 days;

[0081] (5) High seedling treatment: after the cotyledons extend to two leaves and one heart, shade is provided to avoid direct sunlight. The daytime temperature is 25-27°C, the nighttime temperature is 18-20°C, the relative humidity of the air and the substrate is 80-85%, the light duration is 13-14h, and the seedling height treatment is performed at the same time. Specifically, the seedlings are first sprayed with a 0.02-0.025wt% brassinolide solution at a dosage of about 1ml / hole / day. After 1-2 days of treatment, a high seedling treatment agent is sprayed at a dosage of 2ml / hole / day for 1-2 days. After the high seedling treatment, a 0.5-1cm layer of a plant ash substrate mixed with plant ash and a seedling substrate in a mass ratio of 0.5:(1-2) is sprinkled, and then watering is performed to complete the high seedling treatment;

[0082] (6) Growth period: After the high seedling treatment is completed, the daytime temperature is controlled at 25-27°C and the nighttime temperature is 14-15°C. The relative humidity of the air and substrate is 65-70%. The light intensity is increased to more than 35,000 lx, and the light duration is usually 12 hours. Water-soluble fertilizer containing trace elements with an EC value of ≤0.9 mS / cm can be added once or twice, usually for 14-16 days.

[0083] (7) Hardening period: maintain the temperature at 16-20°C during the day and 10-14°C at night, maintain the relative humidity of air and substrate at 50-55%, light duration of 16 hours, light intensity greater than 40,000 lx, and add water-soluble fertilizer containing trace elements with an EC value of ≤1 mS / cm once or twice. After 3-5 days of hardening, cabbage seedlings suitable for transplanter planting are obtained.

[0084] Example 5: Cabbage seedling raising experiment

[0085] The Zhonggan 21 seedling raising experiment was carried out, and the seedling raising process was referred to Example 4:

[0086] (1) Plug tray and disinfection: After the plug tray is disinfected, the seedling medium is placed in the holes;

[0087] (2) Sowing: After adjusting the humidity of the seedling medium, the sterilized seeds are sown in the hole tray, one seedling per hole;

[0088] (3) Seedling stage: The seeds were germinated in a dark place after sowing, and the temperature was maintained at 25°C during the day and 22°C at night. The relative humidity of the air and substrate was 85-90%. The treatment was terminated after 3 days.

[0089] (4) Seedling period: maintain a daytime temperature of 23°C, a nighttime temperature of 16°C, an air and substrate relative humidity of 60-70%, a shading rate of 35%, a photoperiod of 14 h, an intensity greater than 25,000 lx, and end the treatment after 3 days;

[0090] (5) High seedling treatment: the daytime temperature is 26°C, the nighttime temperature is 19°C, the relative humidity of the air and the substrate is 80-85%, the light duration is 14h, the intensity is greater than 25000lx, and the seedling height treatment is carried out at the same time. Specifically, the seedlings are first sprayed with a 0.02wt% brassinolide solution, and the usage amount is about 1ml / hole / day. After 2 days of treatment, the prepared 3-fold diluted high seedling treatment agent is sprayed, and the usage amount is 2ml / hole / day. After 2 days of treatment, a 0.5cm layer of wood ash substrate mixed with wood ash and seedling substrate in a mass ratio of 0.5:1 is sprinkled, and then watering is carried out. Water thoroughly to complete the high seedling treatment, and the treatment is completed for a total of 4 days;

[0091] (6) Growth period: After the high seedling treatment is completed, the daytime temperature is controlled at 26°C and the nighttime temperature is 15°C. The relative humidity of the air and substrate is 65-70%. The light intensity is increased to more than 35,000 lx, and the light duration is usually 12 hours. Water-soluble fertilizer containing trace elements with an EC value of ≤0.9 mS / cm is added once. The treatment is completed for 14 days.

[0092] (7) Hardening period: The temperature was maintained at 18°C ​​during the day and 12°C at night. The relative humidity of the air and substrate was maintained at 50-55%. The light duration was 16 hours and the light intensity was greater than 40,000 lx. During this period, water-soluble fertilizer containing trace elements with an EC value of ≤1 mS / cm was added once. The hardening treatment was terminated after 3 days.

[0093] The experiment consisted of 11 groups, each with 200 plants, and was repeated three times. Experimental Group 1 selected the high seedling treatment agent prepared in Example 1, Control Groups 1-6 selected the high seedling treatment agent prepared in Comparative Examples 1-6, Control Groups 7-8 selected the high seedling treatment agent prepared in Example 1, but the treatment time was different, Control Group 9 only used brassinolide, and Group CK was not treated with the high seedling treatment agent, and a clear water control was selected.

[0094] The high seedling treatment process of the control group 7 was carried out during the seedling stage, and the specific steps were as follows:

[0095] (4) Seedling period: maintain the daytime temperature at 23°C, the nighttime temperature at 16°C, the relative humidity of the air and substrate at 60-70%, the shading rate at 35%, the light duration at 14h, the intensity at greater than 25000lx, and carry out high seedling treatment at the same time. Specifically, first spray the seedlings with a 0.02wt% brassinolide solution at a dosage of about 1ml / hole / day. After 2 days of treatment, spray the prepared 3-fold diluted high seedling treatment agent at a dosage of 2ml / hole / day. After 2 days of treatment, sprinkle a 0.5cm layer of wood ash substrate mixed with wood ash and seedling substrate at a mass ratio of 0.5:1, and then water the seedlings thoroughly to complete the high seedling treatment. The seedling period ends after a total of 7 days of treatment and directly enters the growth period.

[0096] The high seedling treatment process of the control group 8 was carried out during the growth period, and the specific steps were as follows:

[0097] (4) Seedling period: maintain a daytime temperature of 23°C, a nighttime temperature of 16°C, an air and substrate relative humidity of 60-70%, a shading rate of 35%, a photoperiod of 14 h, an intensity greater than 25,000 lx, and end the treatment after 3 days;

[0098] (5) Growth period: control the daytime temperature to 26°C and the nighttime temperature to 15°C, the relative humidity of the air and substrate to 65-70%, increase the light intensity to be greater than 35,000 lx, and the light duration to be 12 hours. At the same time, carry out high seedling treatment. Specifically, first spray the seedlings with a 0.02wt% brassinolide solution at a dosage of about 1 ml / hole / day. After 2 days of treatment, spray the prepared high seedling treatment agent diluted 3 times at a dosage of 2 ml / hole / day. After 2 days of treatment, sprinkle a 0.5 cm layer of wood ash substrate mixed with wood ash and seedling substrate in a mass ratio of 0.5:1, and then water the seeds. Water thoroughly to complete the high seedling treatment. After the high seedling treatment, supplement the water-soluble fertilizer containing trace elements with an EC value of ≤0.9 mS / cm once every 5 days or more. The total growth period is 18 days.

[0099] Control group 9:

[0100] (5) High seedling treatment: the daytime temperature is 26°C, the nighttime temperature is 19°C, the relative humidity of the air and substrate is 80-85%, the light duration is 14h, the intensity is greater than 25000lx, and the seedling height treatment is carried out at the same time. The seedlings are sprayed with a 0.01wt% brassinolide solution at a dosage of about 1ml / hole / day for 1 day. Continue to spray the seedlings with 0.005wt% brassinolide at a dosage of about 1ml / hole / day for 1 day. After the spraying is completed, conventional cultivation is carried out for 2 days, and the total cultivation is completed for 4 days.

[0101] Thirty cabbage seedlings were randomly selected from each group to measure the height of the cabbage seedlings during the seedling raising period, the high seedling treatment period, and the growth period. After the hardening period, the cabbage seedlings were measured for height, stem diameter, and survival rate. The data obtained after taking the average value are shown in Table 1:

[0102] Table 1

[0103]

[0104] 400 cabbage seedlings from each group were selected and transplanted using a transplanter. The survival rate of each group was counted on the 7th day after transplanting under the same management. The data obtained are shown in Table 2:

[0105] Table 2

[0106] Serial number Group Survival rate (%) Serial number Group Survival rate (%) 1 Experimental Group 1 97.5 6 Control group 5 94.5 2 Control group 1 95.75 7 Control group 6 89.75 3 Control group 2 93.25 8 Control group 7 85.75 4 Control group 3 88 9 Control group 8 91.25 5 Control group 4 92.25 10 Control group 9 81.25 11 CK 91

[0107] Analysis of the data in Table 1 and Table 2 shows that:

[0108] 1. The plant height of the experimental group during the seedling period was roughly the same as that of the CK group, but after the high seedling treatment, the plant height of the experimental group increased significantly and reached 14.1cm during the seedling hardening period, and the stem thickness also reached 3.67mm, indicating that the cabbage seedlings were tall and strong after the high seedling treatment, and were particularly suitable for automated transplanting machines. The control group 9 only used brassinolide gradient treatment, which resulted in the cabbage seedlings growing faster in height after the high seedling treatment, but the seedling stems were thinner at the end of the hardening period, and the cabbage seedlings grew too long. Therefore, the survival rate of the seedlings was low after the final hardening period, and because they were thin, the survival rate was also low after machine transplantation.

[0109] 2. When preparing the high seedling treatment agent, compared with the experimental group, the control group 1 did not add magnesium hydroxide treatment. After the high seedling treatment, the plant height began to be continuously lower than that of the experimental group. This is because magnesium hydroxide has an adsorption effect on tannic acid, which prevents the rapid formation of flocs after the mixture of chitosan and tannic acid, resulting in unstable chemical properties of the prepared mixed hydrogel, and it is difficult to achieve the purpose of adsorption-release of brassinolide after the subsequent preparation of the high seedling treatment agent; the control group 2 did not add tannic acid. Although the chitosan solution itself has a certain viscosity, not adding tannic acid will make it difficult for chitosan to form a gel-reducing ionic liquid, and at the same time reduce the sustained-release properties, thus resulting in a lower plant height; the control group 3 did not add choline chloride and urea, resulting in tall but thin seedlings, and a low survival rate. This is because the addition of ionic liquids can not only dissolve tannic acid and brassinolide to achieve the purpose of sustained-release brassinolide, but urea and choline chloride both have certain growth regulating functions, which can promote the growth of cabbage seedlings.

[0110] 3. When preparing the high seedling treatment agent, control group 4 did not add hydrolyzed gelatin, control group 5 increased the amount of chitosan, and control group 6 directly mixed the chitosan gel with the ionic liquid. The overall growth and survival rate of the cabbage seedlings were worse than those of the experimental group. This is because gelatin can not only better mix the ionic liquid and the mixed hydrogel, but also reduce the concentration of the ionic liquid to prevent direct contact with the seedlings. When chitosan reacts with tannic acid, the appropriate amount of chitosan and hydrolyzed gelatin can also improve the performance of chitosan to a certain extent, thereby improving the adsorption-slow release performance of the high seedling treatment agent. When chitosan is excessive or directly mixed with the ionic liquid, the slow release performance is too slow and the gel viscosity is too high, which hinders the effect of the growth regulator on the seedlings, thereby causing the seedlings to have inappropriate plant height and stem thickness, and a low survival rate when transplanted.

[0111] 4. When carrying out the tall seedling treatment, it is preferred to carry out the treatment between the seedling stage and the growth stage, for the cabbage seedlings with two leaves and one heart, to accelerate the elongation of the stem. Due to the strong promoting effect of brassinolide, early treatment will cause the seedlings to grow faster in the initial stage, but the subsequent growth will be delayed, and they will grow into thin seedlings. Delayed treatment will cause the seedlings to grow taller but not thicker, and the leaves will appear wilted and yellow, which will ultimately lead to a low survival rate.

[0112] 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 cabbage seedling raising method suitable for planting by an automatic seedling transplanter, characterized in that: Described seedling raising method is as follows: (1) Plug tray and disinfection: After disinfecting the hard plug tray, put the seedling medium into the hole; (2) Sowing: After adjusting the humidity of the seedling medium, sow the sterilized seeds in the center of the hole; (3) Seedling stage: After sowing, the seeds are germinated in a dark place, the daytime temperature is maintained at 23-27°C, the nighttime temperature is maintained at 20-24°C, and the relative humidity of the air and substrate is maintained at 85-95%. Germination is continued until the cotyledons emerge from the soil; (4) Seedling stage: maintain daytime temperature at 20-24°C, nighttime temperature at 14-18°C, relative humidity of air and substrate at 60-70%, and provide appropriate shade until the cotyledons are fully expanded; (5) High seedling treatment: After the cotyledons have expanded to two leaves and one heart, shade is applied, the daytime temperature is 25-27°C, the nighttime temperature is 18-20°C, the relative humidity of the air and substrate is 80-85%, and the seedling height treatment is carried out at the same time. The high seedling treatment time is 2-4 days. After the high seedling treatment is completed, the plant ash substrate is added again; (6) Growth period: After the high seedling treatment, the daytime temperature is controlled at 25-27°C and the nighttime temperature is controlled at 14-15°C. The relative humidity of the air and substrate is 65-70%. The light intensity is increased and water-soluble fertilizer is added. (7) Hardening period: The temperature is maintained at 16-20°C during the day and 10-14°C at night. The relative humidity of the air and substrate is maintained at 50-55%. After 3-5 days of hardening, the cabbage seedlings suitable for planting by the automatic seedling transplanter are obtained.

2. A cabbage seedling raising method suitable for planting by an automatic seedling transplanter according to claim 1, characterized in that: When cultivating older cabbage seedlings that are more than 30 days old, use a 98- or 105-hole plug tray; when cultivating younger cabbage seedlings that are less than 30 days old, use a 128- or 200-hole plug tray.

3. A cabbage seedling raising method suitable for planting by an automatic seedling transplanter according to claim 2, characterized in that: The seedling medium is mixed according to the mass ratio of perlite: peat soil: mushroom residue of 1:1:

2. Before use, 2 kg of compound fertilizer is added to each cubic meter of the seedling medium.

4. The cabbage seedling raising method suitable for planting by an automatic seedling transplanter according to claim 3, characterized in that: In the step (5), the high seedling treatment is to first spray the cabbage seedlings with a brassinolide solution once, and then spray the cabbage seedlings with a high seedling treatment agent 1-2 days after the spraying, and add a wood ash matrix 1-2 days after the spraying of the high seedling treatment agent.

5. The cabbage seedling raising method suitable for planting by an automatic seedling transplanter according to claim 4, characterized in that: The concentration of the brassinolide solution is 0.02-0.025 wt %, the amount of the brassinolide solution used is 1 ml / well, and the amount of the high seedling treatment agent used is 2 ml / well.

6. The cabbage seedling raising method suitable for planting by an automatic seedling transplanter according to claim 5, characterized in that: In the step (5), after the high seedling treatment is completed, the plant ash matrix treatment is added. The specific operation is: After the tall seedling treatment, sprinkle a 0.5-1 cm layer of wood ash matrix mixed with wood ash and seedling medium in a mass ratio of 0.5: (1-2), and then water the mixture.

7. A cabbage seedling raising method suitable for automatic seedling transplanting machine planting according to any one of claims 1 to 6, characterized in that: In the step (5), the raw materials of the high seedling treatment agent include: Betaine, urea, choline chloride, magnesium hydroxide, hydrolyzed gelatin, tannic acid and chitosan.

8. The cabbage seedling raising method suitable for planting by an automatic seedling transplanter according to claim 7, characterized in that: The mass ratio of chitosan, tannic acid, magnesium hydroxide, betaine, choline chloride, urea and hydrolyzed gelatin is (3-4):1:(0.3-0.5):(0.1-0.2):(1.2-1.3):1:0.

5.

9. The cabbage seedling raising method suitable for planting by an automatic seedling transplanter according to claim 8, characterized in that: The preparation method of the high seedling treatment agent is as follows: (1) adding magnesium hydroxide to a 2-3 wt% tannic acid solution, stirring for 1-2 hours and then standing overnight, then adding 3-4 wt% chitosan solution and betaine, stirring evenly to obtain a mixed hydrogel; (2) After mixing choline chloride and urea, heat them in a water bath to 80° C., stir and react for 60 minutes, add 10-15 wt % hydrolyzed gelatin solution after cooling, stir evenly, add the mixed hydrogel, heat them in a water bath to 40-45° C., stir at high speed for 15-20 minutes, and let stand to obtain a high seedling treatment agent.

10. The cabbage seedling raising method suitable for planting by an automatic seedling transplanter according to claim 9, characterized in that: The high seedling treatment agent is diluted 3-5 times before use.

Images