Plant type adjusting method for improving mechanical harvesting adaptability of non-heading Chinese cabbages

Abstract

The invention discloses a plant type adjusting method for improving mechanical harvesting adaptability of non-heading Chinese cabbages, and belongs to the technical field of agricultural production. According to the method, the non-heading Chinese cabbage is cultured to a one-leaf and one-core period, a treating agent composed of 24-epibrassinolide, gibberellin and monopotassium phosphate is adopted to conduct foliage spraying on seedlings for three times, spraying is conducted every three days, and after treatment is finished, the seedlings are transplanted to flat furrows for planting and culturing when the seedlings grow to three leaves and one core. The non-heading Chinese cabbage plant type suitable for mechanical harvesting is obtained. According to the method, the concentration range of the plant growth regulator and the phosphorus-potassium compound fertilizer is optimized, the combined treating agent can be directly applied to different varieties of non-heading Chinese cabbages, plant hypocotyl elongation is promoted, the upright property is enhanced, the mechanical harvesting quality of the non-heading Chinese cabbages can be improved within a short time, and the operation method is simple and easy to implement. According to the plant type adjusting method for the non-heading Chinese cabbages, the agricultural adaptability of agricultural machinery can be improved in a short time, the variety range suitable for the machinery is widened, and large-scale popularization of mechanical harvesting of the non-heading Chinese cabbages is facilitated.

Description

Technical Field

[0001] This invention belongs to the field of agricultural production technology, specifically relating to a method for adjusting plant type to improve the adaptability of non-heading Chinese cabbage to mechanical harvesting. Background Technology

[0002] Non-heading Chinese cabbage (also known as bok choy, Chinese cabbage, or baby bok choy) is one of the representative leafy vegetables cultivated and consumed in my country. In central and southern my country, it can be grown year-round, and in northern regions, with the help of protected cultivation, it can achieve a high yield of 7-8 harvests per year. Harvesting accounts for approximately 40% of the total workload in non-heading Chinese cabbage production. With the continued shortage of labor and rising labor costs, improving the mechanization of non-heading Chinese cabbage harvesting is now imperative.

[0003] Currently, most non-heading Chinese cabbage varieties are bred with a compact and aesthetically pleasing plant shape, growing close to the ground. However, this results in excessive damage during mechanized harvesting. Therefore, varieties suitable for mechanized harvesting require a certain hypocotyl height and upright growth. Most current varieties grow close to the ground, and their hypocotyl length is insufficient for mechanized harvesting. A few varieties with longer hypocotyls suitable for mechanized harvesting, such as 'Xinxiaqing 6' and 'Xinxiaqing 9', are mainly suitable for Shanghai and surrounding leafy vegetable production areas, and are produced as a fast-growing type of leafy green. Because non-heading Chinese cabbage exhibits significant regional differentiation, and consumers have vastly different requirements for appearance and texture, the current pace of variety innovation and improvement (4-6 years) is insufficient to meet the variety demands of mechanized harvesting in different regions. If existing superior varieties could be modified through exogenous substances to adjust plant shape and increase hypocotyl height, the mechanized harvesting of non-heading Chinese cabbage could be scaled up more efficiently and with lower inputs, in addition to variety innovation.

[0004] Currently, there is no technical system for improving the adaptability of non-heading Chinese cabbage to machine harvesting through growth regulation measures, and related reports and applications are all blank. Summary of the Invention

[0005] Based on the above-mentioned technical shortcomings, the purpose of this invention is to provide a method for adjusting plant type to improve the adaptability of non-heading Chinese cabbage to mechanical harvesting. This invention directly uses existing superior non-heading Chinese cabbage varieties as the target for plant type adjustment, utilizing safe and environmentally friendly plant growth regulators combined with phosphorus and potassium compound fertilizers to enhance the hypocotyl length and uprightness of the plants. This overcomes the current bottleneck of poor mechanized harvesting results for non-heading Chinese cabbage caused by long variety selection cycles and a shortage of new varieties suitable for mechanical harvesting.

[0006] To achieve the above-mentioned objectives, the present invention employs the following technical solution: This invention provides a method for adjusting plant type to improve the mechanical harvesting adaptability of non-heading Chinese cabbage, the method comprising the following steps: (1) Cultivate non-heading Chinese cabbage seedlings to the stage of one leaf and one heart, and then spray them for the first time with a combination treatment agent; (2) Three days after the first spraying treatment, a second spraying treatment is carried out using a combination treatment agent; (3) Three days after the second spraying treatment, a third spraying treatment was carried out using a combination treatment agent; (4) After the three spraying treatments are completed, the seedlings are transplanted to flat beds when they grow to three leaves and one heart, so as to obtain a non-heading Chinese cabbage plant type that is adapted to mechanical harvesting.

[0007] Furthermore, the combined treatment agent includes a plant growth regulator and a phosphorus-potassium compound fertilizer. The plant growth regulator includes 24-epibrassinolide and gibberellin, and the phosphorus-potassium compound fertilizer includes potassium dihydrogen phosphate. Based on the mass concentration in the combined treatment agent solution, the mass concentration of 24-epibrassinolide is 0.05 ~ 0.1 mg / L, the mass concentration of gibberellin is 280 ~ 300 mg / L, and the mass concentration of potassium dihydrogen phosphate is 4 ~ 7 g / L.

[0008] Furthermore, the first spraying treatment was scheduled to be carried out when the second true leaf emerged from the growing point.

[0009] Furthermore, the first spraying treatment is applied 9 to 10 days after the seeds sprout.

[0010] Furthermore, the spraying treatment includes foliar spraying or foliar spraying combined with applying the hypocotyl.

[0011] Furthermore, the amount of foliar spraying is sufficient to moisten the cotyledon and leaf surfaces without forming droplets.

[0012] Furthermore, the operation of foliar spraying combined with smearing the hypocotyl includes the following: first, spray the foliage to moisten the cotyledon and leaf surface without forming droplets; after the foliar spraying is completed, dip a pen in the combined treatment agent, filter off the excess liquid along the container wall, and smear it around the hypocotyl.

[0013] Furthermore, in the optimized plant type adjustment method, the components and mass concentrations of the combined treatment agent are: 0.05 mg / L of 24-epibrassinolide, 300 mg / L of gibberellin, and 6.67 g / L of potassium dihydrogen phosphate.

[0014] Furthermore, in the optimized plant type adjustment method, the spraying treatment is foliar spraying.

[0015] Furthermore, in the plant type adjustment method for improving the mechanical harvesting adaptability of non-heading Chinese cabbage, the variety type of non-heading Chinese cabbage is not limited to short hypocotyl varieties.

[0016] Furthermore, in step (4), the planting method of transplanting to the flat bed after the spraying treatment can also be adjusted to direct seeding on the flat bed using a small seed planter at the specified plant spacing, and then treated with the same spraying method.

[0017] Compared with existing technologies, the effects and advantages of this invention are: This invention targets existing superior non-heading Chinese cabbage varieties for plant type adjustment. It employs plant-oriented selection of exogenous growth regulators and establishes a new concentration ratio system that can be directly applied to varieties already promoted in different regions. By spraying a combination of plant growth regulators and fertilizers during the early seedling growth stage, it promotes hypocotyl elongation and enhances upright growth, thereby improving the quality of mechanized harvesting of non-heading Chinese cabbage in a short time. The operation is simple and easy to implement. Compared to the method of selecting and promoting machine-suitable varieties to match harvesting machinery, the plant type adjustment method for non-heading Chinese cabbage provided by this invention optimizes the plant type of existing varieties, improves agronomic and agricultural machinery adaptability, and greatly increases the selection range of machine-suitable varieties, thus promoting the large-scale mechanized harvesting process in non-heading Chinese cabbage production areas. Attached Figure Description

[0018] Figure 1 This is a statistical chart showing the hypocotyl length and diameter of the short hypocotyl varieties 'Nentouqing' and 'Shenglong' after three treatments with a combination of 16 treatment agents, seven days after the end of treatment. Data were analyzed using Duncan's new multiple range method for multiple comparisons; bars with the same letter at the top indicate no significant difference at the 5% level.

[0019] Figure 2 Comparison of phenotypes of 'Shenglong' after three treatments with different concentrations of regulators.

[0020] Figure 3 The changes and morphology of the hypocotyl of the short hypocotyl variety 'Nentouqing' were compared 7 days after transplanting after three treatments. The plant on the left was treated with water (control), and the plant on the right was treated with a combination of 0.05 mg / L BR + 300 mg / L GA3 + 6.67 g / L KH2PO4.

[0021] Figure 4 To compare the effects of three different treatments on the hypocotyl length of the 'Nentouqing' variety, the treatment combination was 0.05 mg / L BR + 300 mg / L GA3 + 6.67 g / L KH2PO4. The three treatments were foliar spraying, hypocotyl application, and foliar spraying + hypocotyl application, with water spraying serving as a control.

[0022] Figure 5This study compared the changes and morphology of hypocotyls in the short hypocotyl varieties 'Dongfei 93-1' and 'Xinfu Qinggengcai' after three treatments and 15 days after transplanting. In A, the three plants on the left in A represent the water treatment group (control), and the three plants on the right in A represent the combined treatment group. In B, the three plants on the left in B represent the water treatment group (control), and the three plants on the right in B represent the combined treatment group.

[0023] Figure 6 This study compares the plant morphology of the short hypocotyl variety 'Liangchun' at harvest time in the field. The two plants on the left were treated with water (control), while the two plants on the right were treated with a combination of 0.05 mg / L BR + 300 mg / L GA3 + 6.67 g / L KH2PO4. Detailed Implementation

[0024] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited to the scope of the examples described.

[0025] Example 1 This embodiment uses orthogonal analysis to design concentration combinations and compare the effects of different treatments on the plant height and appearance of non-heading Chinese cabbage, including the following steps: 1. Experimental Design: L16(4) was adopted. 3 A 3-factor, 4-level orthogonal design was used, and an orthogonal table (Table 1) was generated, containing 16 treatment agent ratios, with distilled water treatment as a control. The mass concentrations of gibberellin (GA3) in the combined treatment agent solutions were set as follows: 0, 100, 200, and 300 mg / L; 0, 0.05, 0.1, and 0.2 mg / L of 24-epibrassinolide (BR); and 0, 4.67, 6.67, and 8.67 g / L of potassium dihydrogen phosphate (KH2PO4). Based on the design results, combined treatment agent solutions with different ratios were prepared.

[0026] Table 1 Three-factor four-level L16 (4 3 Orthogonal Design Coding Table

[0027] Note: The numbers in parentheses are the concentration levels of each component in the treatment agent.

[0028] 2. Non-heading Chinese cabbage varieties 'Nentouqing' and 'Shenglong', sown in seedling trays and grown to one leaf and one bud, were divided into 16 groups, with 3 replicates per group. The 16 combinations of treatment agents listed in Table 1 were used for the first application of each group. 3. Three days after the first spraying treatment, a second spraying treatment was carried out using the 16 combinations of treatment agents described in Table 1. 4. Three days after the second spraying treatment, a third spraying treatment was carried out using the 16 combinations of treatment agents described in Table 1. 5. After three spraying treatments, transplant the seedlings to flat beds when they have grown to 3 leaves and buds.

[0029] The first spraying after sowing should be done when the second true leaf emerges from the growing point, approximately 9-10 days after seed emergence. Treatment at this time effectively avoids the rapid growth phase of the hypocotyl after seed germination (lasting approximately 6-7 days), preventing exogenous treatment agents from interfering with normal seedling morphology, significantly reducing the risk of excessive growth and weakening, and improving seedling quality. If treatment is done too late, the secondary xylem of the hypocotyl in the seedling has already undergone a high degree of lignification, and the large amount of lignin deposition stabilizes the cell wall structure, resulting in less significant effects from subsequent treatments.

[0030] All three spraying treatments were foliar spraying treatments, with each spray amount sufficient to moisten the cotyledon and leaf surfaces without forming droplets.

[0031] Seven days after spraying, i.e., 25 days after sowing, the hypocotyl length, diameter, and plant type of 'Nentouqing' and 'Shenglong' were investigated. Through orthogonal experimental analysis, the optimal factor levels for promoting hypocotyl elongation and thickening of 'Nentouqing' (Tables 1 and 2) and 'Shenglong' (Tables 3 and 4) were determined, thereby obtaining the optimal combination and the primary and secondary relationships of the influence of each factor.

[0032] Table 2. Analysis of orthogonal test results for hypocotyl length of 'Nentouqing' cultivar

[0033] Table 2 shows that the optimal combination for promoting the increase of hypocotyl length in 'Nentouqing' was A2B4C3, namely, a treatment combination of 0.05 mg / L brassinolide, 300 mg / L gibberellin, and 6.67 g / L potassium dihydrogen phosphate. The range R and the order of importance (B > A > C) indicate that gibberellin (factor B) had the greatest impact on hypocotyl length in 'Nentouqing', followed by 24-epibrassinolide (factor A), and then potassium dihydrogen phosphate (factor C).

[0034] Table 3. Analysis of orthogonal test results for hypocotyl diameter of 'Nentouqing' cultivar

[0035] Table 3 shows that the optimal combination for promoting the increase of hypocotyl diameter in 'Nentouqing' was A3B4C2, namely, a treatment combination of 0.1 mg / L of 24-epibrassinolide, 300 mg / L of gibberellin, and 4.67 g / L of potassium dihydrogen phosphate. The range R and the order of importance (B > A > C) indicate that gibberellin (factor B) had the greatest impact on hypocotyl diameter in 'Nentouqing', followed by 24-epibrassinolide (factor A), and then potassium dihydrogen phosphate (factor C).

[0036] Table 4. Analysis of Orthogonal Experiment Results of Hypocotyl Length of 'Shenglong'

[0037] Table 4 shows that the optimal treatment combination for promoting hypocotyl length increase in 'Shenglong' was A2B4C3, consistent with the analysis results for 'Nentouqing', namely, a treatment combination of 0.05 mg / L 24-epibrassinolide, 300 mg / L gibberellin, and 6.67 g / L potassium dihydrogen phosphate. The range R and the order of importance (B > C > A) indicate that gibberellin (factor B) had the greatest impact on hypocotyl length in 'Nentouqing', followed by potassium dihydrogen phosphate (factor C), and then 24-epibrassinolide (factor A).

[0038] Table 5 Analysis of Orthogonal Test Results of Hypocotyl Diameter of 'Shenglong'

[0039] Table 5 shows that the optimal combination for promoting the increase of hypocotyl diameter in 'Shenglong' was A3B4C2, consistent with the analysis results for 'Nentouqing', namely, a treatment combination of 0.1 mg / L of 24-epibrassinolide, 300 mg / L of gibberellin, and 4.67 g / L of potassium dihydrogen phosphate. The range R and the order of importance (B > C > A) indicate that gibberellin (factor B) had the greatest impact on hypocotyl diameter in 'Nentouqing', followed by potassium dihydrogen phosphate (factor C), and then 24-epibrassinolide (factor A).

[0040] The above results indicate that the A2B4C3 combination is the optimal treatment combination for promoting the increase of hypocotyl length in both 'Nentouqing' and 'Shenglong' varieties, while the A3B4C2 treatment combination is the optimal combination for promoting the thickening of hypocotyl in both varieties.

[0041] Analysis of the differences among the 16 treatment combinations showed that ( Figure 1When the treatment combination was A2B4C3 (0.05 mg / L brassinolide, 300 mg / L gibberellin, and 6.67 g / L potassium dihydrogen phosphate), the hypocotyl length of 'Nentouqing' and 'Shenglong' varieties was significantly higher than other combinations, reaching 24.36 mm and 25 mm respectively, representing increases of 69.3% and 69.1% compared to the control. The second best combination was A2B3C4, which increased hypocotyl length by 58.3% and 55.6% compared to the control. Regarding hypocotyl diameter, all treatments containing gibberellin significantly thickened the hypocotyl, while the combination with a gibberellin concentration of 0 mg / L showed no difference from the control. This indicates that gibberellin is also crucial for regulating hypocotyl thickening in non-heading Chinese cabbage. The treatment combination A3B4C2 (0.1 mg / L of 24-epibrassinolide, 300 mg / L of gibberellin, and 4.67 g / L of potassium dihydrogen phosphate) showed the most significant promoting effect on hypocotyl thickening in both varieties. The effects of the 16 treatment combinations on plant height varied considerably. Figure 2 Among them, the non-heading Chinese cabbage seedlings treated with the combination of treatment agent A2B4C3 maintained the length advantage of their hypocotyls throughout the entire growth period after transplanting to the field. Figure 3 ).

[0042] Based on the above results, gibberellin (factor B) is the most significant factor affecting hypocotyl elongation and thickening. 24-epibrassinolide and potassium dihydrogen phosphate, as secondary factors, exhibited a specific order of effect due to differences in varietal endogenous hormone levels and signal responses. Considering that hypocotyl length is a more critical factor affecting harvest damage rate during mechanized harvesting, the optimal treatment combination for promoting hypocotyl elongation and thickening in non-heading Chinese cabbage, as determined in this invention, is a combination of 0.05 mg / L 24-epibrassinolide, 300 mg / L gibberellin, and 6.67 g / L potassium dihydrogen phosphate.

[0043] Example 2 This embodiment employs three exogenous regulator treatment methods: foliar spraying, hypocotyl application, and a combination of foliar spraying and hypocotyl application, with water spraying serving as a control. The effects of different treatment methods on hypocotyl elongation are compared. The combined treatment agents described in this embodiment consist of 0.05 mg / L of 24-epibrassinolide, 300 mg / L of gibberellin, and 6.67 g / L of potassium dihydrogen phosphate.

[0044] The treatment method using three exogenous regulators includes the following steps: 1. For the non-heading Chinese cabbage variety 'Liangchun' seedlings sown in plug trays and grown to one leaf and one bud, a first treatment with a combination of agents is applied. This treatment includes foliar spraying, application to the hypocotyl, and a combination of foliar spraying and application to the hypocotyl as an exogenous regulator. Specific procedures are as follows: ① Foliar spraying: Apply enough to moisten the cotyledons and leaves without forming droplets; ② Hypocotyl application: Dip a 5mm wide painting brush in the treatment solution, filter off excess liquid along the container wall, and apply the solution around the hypocotyl; ③ Foliar spraying + hypocotyl application: Apply enough to moisten the cotyledons and leaves without forming droplets; then, dip a 5mm wide painting brush in the treatment solution, filter off excess liquid along the container wall, and apply the solution around the hypocotyl. 2. Three days after the first treatment, a second treatment using a combination of treatment agents was performed, with the treatment method being the same as the first treatment; 3. Three days after the second spraying, apply a third spraying with the combined treatment agent, using the same treatment method as the first spraying. 4. After three spraying treatments, transplant the seedlings to flat beds when they have grown to 3 leaves and buds.

[0045] The first spraying time after sowing is determined to be when the second true leaf emerges from the growing point, which is about 9-10 days after the seeds sprout.

[0046] Measurements were taken 15 days after transplanting, and the results were as follows. Figure 4 As shown, among the three treatment methods, while applying only the hypocotyl significantly increased hypocotyl height compared to the control, it did not bring the hypocotyl height of short hypocotyl varieties to the level required for mechanized harvesting. Both foliar spraying and a combination of foliar spraying and hypocotyl application increased the hypocotyl length of the 'Nentouqing' variety to more than 3.6 times its original length, approaching 3 cm. Furthermore, there was no significant difference in the effect of the two treatment methods on promoting hypocotyl growth. Considering the ease of operation, foliar spraying is lower in cost and saves more labor. Therefore, this invention determines foliar spraying as the preferred method for exogenous substance treatment.

[0047] Example 3 In this embodiment, different short hypocotyl varieties were treated with growth regulators. The combined treatment agents described in this embodiment were 0.05 mg / L of 24-epibrassinolide, 300 mg / L of gibberellin, and 6.67 g / L of potassium dihydrogen phosphate.

[0048] 1. The seedlings of short hypocotyl non-heading Chinese cabbage varieties 'Liangchun', 'Dongfei 93-1', and 'Xinfu Qinggengcai', which have grown to one leaf and one bud in the seedling trays, were sprayed for the first time with a combination treatment agent; 2. Three days after the first spraying treatment, a second spraying treatment using a combination treatment agent should be carried out; 3. Three days after the second spraying treatment, a third spraying treatment using a combination treatment agent should be carried out; 4. After three spraying treatments, transplant the seedlings to flat beds when they have grown to 3 leaves and buds.

[0049] The first spraying time after sowing is determined to be when the second true leaf emerges from the growing point, about 9-10 days after the seed sprouts.

[0050] The spraying treatment method is foliar spraying, and the amount of spraying each time is enough to moisten the cotyledon and leaf surface without forming droplets.

[0051] Table 6. Effects of combined treatments on hypocotyl length of different varieties of non-heading Chinese cabbage.

[0052] Note: Duncan's new multiple range method was used for multiple comparisons. Data with the same letter after the same column indicate that there is no significant difference at the 5% level.

[0053] Measurements were taken 15 days after transplanting, and the results are shown in Table 6. Figure 5 , Figure 6 As shown, after treatment with the combined treatment agent and application method provided by this invention, the three varieties 'Liangchun', 'Xinfu Qinggengcai', and 'Dongfei 93-1' all exhibited a significantly elongated hypocotyl phenotype under field planting conditions, with lengths exceeding the control by 43.1%, 45.7%, and 58%, respectively. In summary, this invention demonstrates that the treatment agent, within a suitable range, can effectively promote hypocotyl growth in different types of non-heading Chinese cabbage.

[0054] The above examples only represent the technical solutions of this invention and are not intended to limit the experiments. Although we have improved the experimental scheme, researchers in the same field can still further improve the experimental scheme described above or make scientifically equivalent substitutions for the experimental steps. These changes do not cause the substance of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions claimed in this invention.

Claims

1. A method for adjusting plant type to improve the mechanical harvesting adaptability of non-heading Chinese cabbage, characterized in that, The plant type adjustment method includes the following steps: (1) Cultivate non-heading Chinese cabbage seedlings to the stage of one leaf and one heart, and then spray them for the first time with a combination treatment agent; (2) Three days after the first spraying treatment, a second spraying treatment is carried out using a combination treatment agent; (3) Three days after the second spraying treatment, a third spraying treatment was carried out using a combination treatment agent; (4) After the three spraying treatments are completed, the seedlings are transplanted to flat beds when they grow to three leaves and one heart, so as to obtain a non-heading Chinese cabbage plant type that is adapted to mechanical harvesting.

2. The plant type adjustment method according to claim 1, characterized in that, The combined treatment agent includes a plant growth regulator and a phosphorus-potassium compound fertilizer. The plant growth regulator includes 24-epibrassinolide and / or gibberellin, and the phosphorus-potassium compound fertilizer includes potassium dihydrogen phosphate. Based on the mass concentration in the combined treatment agent solution, the mass concentration of 24-epibrassinolide is 0.05 ~ 0.1 mg / L, the mass concentration of gibberellin is 280 ~ 300 mg / L, and the mass concentration of potassium dihydrogen phosphate is 4 ~ 7 g / L.

3. The plant type adjustment method according to claim 1, characterized in that, The timing of the first spraying treatment is determined to be either when the second true leaf emerges from the growing point or 9-10 days after the seeds sprout.

4. The plant type adjustment method according to claim 1, characterized in that, The spraying treatment methods include foliar spraying or foliar spraying combined with applying the hypocotyl.

5. The plant type adjustment method according to claim 4, characterized in that, The amount of foliar spraying is sufficient to moisten the cotyledon and leaf surfaces without forming droplets.

6. The plant type adjustment method according to claim 4, characterized in that, The operation of foliar spraying combined with smearing the hypocotyl includes the following steps: First, spray the foliage to moisten the cotyledon and leaf surface without forming droplets; after spraying the foliage, dip a brush into the combined treatment agent, filter off the excess liquid along the container wall, and smear it around the hypocotyl.

7. The plant type adjustment method according to any one of claims 1 to 6, characterized in that, In the optimized plant type adjustment method, the components and mass concentrations of the combined treatment agent are: 0.05 mg / L of 24-epibrassinolide, 300 mg / L of gibberellin, and 6.67 g / L of potassium dihydrogen phosphate.

8. The plant type adjustment method according to any one of claims 1 to 6, characterized in that, In the optimized plant type adjustment method, the spraying treatment is foliar spraying.

9. The plant type adjustment method according to any one of claims 1 to 6, characterized in that, The plant type adjustment method for improving the mechanical harvesting adaptability of non-heading Chinese cabbage is not limited to short hypocotyl varieties.

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