Method for improving lettuce seedling culture quality under weak light background

Abstract

The invention belongs to the technical field of crop planting, and discloses a method for improving lettuce seedling culture quality under a weak light background. The method comprises the following steps: accelerating germination of lettuce seeds, and sowing the lettuce seeds after the lettuce seeds are germinated for 1-2 days; sowing and seedling raising are conducted on the seeds with white buds; wherein in the sowing and seedling raising stage, the seedling raising environment temperature is controlled to be 23-25 DEG C, the relative humidity is maintained to be 60%-70%, the white light intensity is set to be 120 mu mol / m < 2 > / s according to the weak light irradiation intensity, the light period is 14 h / 10 h, 100 mu mol / m < 2 > / s red and blue light is supplemented, and the light quality of the red and blue light is 7: 3 or 2: 3. Compared with an existing light supplementing technology, the low-light environment is considered, red light and blue light are supplemented after the low-light environment serves as background light, input of light supplementing light intensity can be reduced in actual application, and input of electric energy is reduced to a certain degree. According to the scheme, the seedling raising effect is obviously improved, and the seedling strengthening index, the whole plant dry weight and the leaf number are obviously increased.

Description

Technical Field

[0001] The invention relates to the technical field of crop planting, and in particular to a method for improving the quality of lettuce seedling cultivation under a weak light background. Background Art

[0002] Lettuce is a common vegetable in people's daily life. The demand for seedlings in production is relatively large. Exploring a lighting scheme suitable for the lettuce seedling period is of positive significance to lettuce production. At present, there are many schemes for lighting supplement for lettuce growth. There is a related patent that shows that the quality of lettuce can be improved by changing the light environment (publication number: CN 118177060 A). This patent is for seedling cultivation on rock wool blocks and does not take into account the natural background light of seedling cultivation in actual production. The present invention explores the phenomenon that lettuce seedlings grow poorly in a weak light environment, and supplements light by simulating weak light environment conditions, and explores a lighting supplement scheme for lettuce seedling cultivation in low light areas and poor light conditions, providing a reference for ensuring the quality of lettuce seedlings.

[0003] Under weak light conditions, using light regulation technology to cultivate strong vegetable seedlings is a simple and easy method. Lettuce is a common vegetable crop in plant factories and is also widely grown in the field. The market demand for lettuce is huge, so a large supply of seedlings is needed to ensure production. In areas with little light, haze and frequent rainy days, lettuce seedlings will be adversely affected, and an accurate light supplement scheme is needed to alleviate the impact of weak light environment on seedlings. Most of the existing light supplement schemes are carried out by directly supplementing light quality in different proportions, without considering the natural light environment that can be used during seedling cultivation. This light supplement scheme is suitable for closed plant factory seedling cultivation, but it is easy to cause excessive consumption of electricity when used in plastic greenhouses, glass greenhouses and other natural light facilities, which is not conducive to controlling seedling costs. In areas with little light and haze and rainy environments, there is still a certain amount of natural light that can be used. Combining this part of weak light for light supplement can reduce the investment during the light supplement period to a certain extent, which is very helpful in reducing the investment during the seedling period. Summary of the invention

[0004] The invention aims to improve the effect of raising lettuce seedlings under low light conditions and increase the seedling index and growth rate of lettuce seedlings under low light conditions.

[0005] The technical solution adopted by the present invention is: A method for improving the quality of lettuce seedlings under a weak light background, comprising: The lettuce seeds are germinated, and the seeds are sown after 1-2 days of germination when they turn white; Sow and raise seedlings of white seeds; During the seeding and seedling raising stage, the temperature of the seedling raising environment was controlled at 23-25°C, the relative humidity was maintained at 60%-70%, and the white light intensity was set to 120 umol / m 2 / s, photoperiod of 14h / 10h, supplemented with 100umol / m 2 / s of red and blue light, the light cycle is 14h / 10h, and the light quality of red and blue light is 7:3 or 2:3.

[0006] Preferably, the light quality of red and blue light is 7:3.

[0007] Preferably, the germination method is: placing the seeds in a culture dish covered with filter paper, and then covering the culture dish with the filter paper, keeping the culture dish moist and free of water, and the ambient temperature is 23-25°C.

[0008] Preferably, the seedling substrate used in the seedling raising process is obtained by mixing peat, perlite and vermiculite in a mass ratio of 9:3:1 and sterilizing the mixture.

[0009] Preferably, sterilization is carried out at 121°C for 15-20 minutes.

[0010] Preferably, during the sowing and seedling raising stage, tidal irrigation is performed every two days, with clean water used for irrigation before true leaves grow out, and nutrient solution used for irrigation after true leaves begin to grow out.

[0011] Preferably, the pH value of the nutrient solution is 6.5-7.5, and the EC value is 1200-1300 μS / cm.

[0012] Compared with the prior art, the present invention has the following beneficial effects: Compared with the existing supplementary lighting technology, the present invention takes into account the weak light environment and uses it as background light to supplement red and blue light. In actual application, it can reduce the input of supplementary light intensity and reduce the input of electric energy to a certain extent. The seedling raising effect under this scheme is significantly improved, and the seedling index, whole plant dry weight and leaf number are significantly improved. In the treatment of supplementing red and blue light with different proportions, the white light intensity of 120umol / m 2 / s combined with a red-blue light quality of 7:3 or 2:3 supplementary lighting scheme has a good effect on the seedling growth of lettuce (Huqian, Zhongsheng No. 1). When the red-blue light quality is 7:3, the dry weight of the whole plant of Huqian and Zhongsheng No. 1 under weak light conditions increased by 134.4% and 136.1% respectively; when the red-blue light quality is 2:3, the dry weight of the whole plant of Huqian and Zhongsheng No. 1 under weak light conditions increased by 104.1% and 161.0% respectively. The present invention can solve the impact of weak light environment on lettuce seedling cultivation. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is the seedling index of Huqian under different treatments; Figure 2 This is the seedling index of Zhongsheng No. 1 under different treatments. DETAILED DESCRIPTION

[0014] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments.It should be understood that these descriptions are exemplary only, and are not intended to limit the scope of the present invention.In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.Unspecified conditions in the embodiments are carried out according to the conditions of normal conditions or manufacturer recommendations.Reagents used or instruments that do not specify manufacturers are conventional products that can be purchased and obtained commercially.

[0015] In order to solve the shortcoming of the existing supplementary lighting technology that ignores the weak light background inside the facility, the embodiment of the present invention proposes a solution for supplementary lighting under a weak light background environment to improve the quality of lettuce seedlings. The embodiment of the present invention is carried out in a closed plant factory, and the weak white light background is determined according to the average actual light intensity of seedlings in plastic greenhouses in Chengdu in winter, and then a supplementary lighting experiment is carried out under this background light intensity. This supplementary lighting scheme takes into account the effective natural light environment, and can reduce the input of supplementary light energy during seedling cultivation under insufficient light conditions to a certain extent. Moreover, this supplementary lighting scheme can significantly improve the seedling index of lettuce seedlings and also has a certain promoting effect on the growth rate of seedlings. Supplementary lighting can also significantly improve the underground growth of lettuce seedlings, so this supplementary lighting scheme has certain potential in shortening the seedling acclimatization time and growth state after seedling transplanting.

[0016] The embodiment of the present invention provides a method for improving the quality of lettuce seedlings under a weak light background, comprising: germinating lettuce seeds, sowing the seeds after germination for 1-2 days until the seeds are white; sowing and raising seedlings of the white seeds; wherein, during the sowing and raising seedling stage, the temperature of the seedling raising environment is controlled at 23-25°C, the relative humidity is maintained at 60%-70%, and the white light intensity is set to 120 umol / m according to the weak light irradiation intensity. 2 / s, photoperiod of 14h / 10h, supplemented with 100umol / m 2 / s of red and blue light, the light cycle is 14h / 10h, and the light quality of red and blue light is 7:3 or 2:3.

[0017] In the following, the light quality of red and blue light is 7:3 or 2:3, which is recorded as 7R:3B or 2R:3B respectively.

[0018] Since plants mainly absorb red and blue spectra for photosynthesis, other wavelengths of light also have certain positive effects on plant growth. Therefore, supplementing red and blue light in a full-spectrum weak light environment has a positive significance for plant growth. The embodiments of the present invention simulate the weak light intensity of the environment through white light, and unexpectedly found that supplementing 7R:3B and 2R:3B spectra under a weak light background significantly improves the seedling effect of lettuce, and when the 7R:3B spectrum is supplemented, the improvement effect on lettuce seedling is the best.

[0019] The germination method, seedling tray, seedling substrate, nutrient solution, irrigation method, etc. in the lettuce seedling raising process are all commonly used means in the field and can be selected by those skilled in the art according to actual conditions.

[0020] In order to make the technical solution of the present invention clearer, the method and effect of improving the quality of lettuce seedlings under a weak light background are described in detail below through multiple specific embodiments.

[0021] Example 1 Step 1 (setting the light environment for seedling cultivation): The temperature of the seedling cultivation environment is controlled in the range of 23-25℃, and the humidity is maintained in the range of 60%-70%. Use LED white light to simulate the natural weak light environment, and set the light cycle to 14h / 10h. Refer to the weak light intensity inside the plastic greenhouse and set the white light intensity to 120umol / m 2 / s. Then add 100umol / m 2 / s of red and blue light, the light cycle is 14h / 10h, and the ratio of red light to blue light is set in multiple experimental groups and control groups, as shown in Table 1, R represents red light, B represents blue light, for example, "7R:3B" means that the red and blue light quality ratio is 7:3; "W120" represents the intensity of white light, that is, white light 120umol / m 2 / s; "W120+R" represents the white light intensity of 120umol / m 2 / s combined with 100umol / m 2 / s of pure red light.

[0022] Step 2 (germination): Place the lettuce seeds in a culture dish covered with filter paper and cover with filter paper. Then wet the filter paper with clean water to ensure that the moisture content inside the culture dish is constant. It is best to place the culture dish at room temperature of 23-25℃ so that there is no water accumulation in the culture dish. Sow the seeds after 1-2 days when they turn white. During this period, keep the water content inside the culture dish sufficient to avoid insufficient humidity.

[0023] Step 3 (preparation of seedling medium): Select a clean, non-toxic hole tray with 105 holes for seedling cultivation. The ratio of seedling medium is peat: perlite: vermiculite = 9:3:1. Sterilize the mixed medium at 121℃ for 15-20 minutes. Add water to the sterilized medium and stir evenly. The amount of water added should be enough for the medium to hold without falling apart. Then put the medium into the seedling tray for use.

[0024] Step 4 (Sowing): Select white seeds for sowing, place one seed in each hole, and then cover the surface with a thin layer of substrate. After sowing, place the trays under the corresponding fill light for cultivation, and perform tidal irrigation to ensure that the substrate is fully soaked.

[0025] Step 5 (seedling management): Tidal irrigation is carried out every two days. Use clean water for irrigation before the true leaves grow out, and use nutrient solution for irrigation after the true leaves begin to grow out. The pH value of the nutrient solution is 6.5-7.5, and the EC value is controlled at 1200-1300μS / cm. The nutrient solution is filtered and returned to the storage tank for recycling.

[0026] The above seedling raising methods were applied to the seeds of Huqian and Zhongsheng No. 1 respectively. The data of each experimental group and control group of Huqian and Zhongsheng No. 1 obtained by the above method were statistically measured on the 18th day after sowing, including plant height, stem diameter, whole plant dry weight and number of leaves, to compare the growth differences of lettuce under different treatments. The results are shown in Table 1-2. The seedling index of Huqian and Zhongsheng No. 1 was calculated, and the seedling index = (stem diameter / plant height + underground dry weight / above ground dry weight) * total dry weight. The results are as follows Figure 1 , 2 shown.

[0027] Table 1 Growth differences of Huqian under different supplementary light treatments .

[0028] Table 2 Growth differences of Zhongsheng 1 under different supplementary light treatments .

[0029] It can be seen from Table 1-2 that the lettuce has a good seedling growth effect and dry matter accumulation when supplemented with 7R:3B and 2R:3B, and has a significant effect on improving the leggy growth of seedlings. Various morphological indicators are significantly better than those in weak light environments. The number of leaves of seedlings can be used to indicate the growth rate of seedlings. Statistical results show that supplementary light can also effectively promote the growth rate of seedlings. Therefore, this supplementary light scheme has a positive effect on improving the quality of lettuce seedlings under weak light environments. Compared with other treatment groups, the whole plant dry weight, stem thickness and number of leaves of W120+7R:3B and W120+2R:3B are at a higher level, and the inhibitory effect on plant leggy growth is also relatively obvious.

[0030] pass Figure 1-2 It can be seen that the 7R:3B and 2R:3B supplementary lighting schemes have shown good seedling growth effects on both varieties of lettuce. Therefore, supplementing the 7R:3B and 2R:3B spectrum in a weak light environment is better for improving the lettuce seedling effect.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for improving the quality of lettuce seedlings under weak light background, characterized in that: Include: The lettuce seeds are germinated, and the seeds are sown after 1-2 days of germination when they turn white; Sow and raise seedlings of white seeds; During the seeding and seedling raising stage, the temperature of the seedling raising environment was controlled at 23-25°C, the relative humidity was maintained at 60%-70%, and the white light intensity was set to 120 umol / m 2 / s, photoperiod of 14h / 10h, supplemented with 100umol / m 2 / s of red and blue light, the light cycle is 14h / 10h, and the light quality of red and blue light is 7:3 or 2:

3.

2. The method according to claim 1, characterized in that The light quality of red and blue light is 7:

3.

3. The method according to claim 1, characterized in that The method of germination is: place the seeds in a culture dish covered with filter paper, then cover it with filter paper, keep the culture dish moist but without water accumulation, and the ambient temperature is 23-25℃.

4. The method according to claim 1, characterized in that The seedling medium used in the seedling raising process is obtained by mixing peat, perlite and vermiculite in a mass ratio of 9:3:1 and then sterilizing the mixture.

5. The method according to claim 4, characterized in that Sterilize at 121°C for 15-20 minutes.

6. The method according to claim 1, characterized in that During the sowing and seedling stage, tidal irrigation is carried out every two days. Use clean water for irrigation before the true leaves grow, and use nutrient solution for irrigation after the true leaves begin to grow.

7. The method according to claim 6, characterized in that The pH value of the nutrient solution is 6.5-7.5, and the EC value is 1200-1300 μS / cm.

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