A method for cultivating ratoons of rice according to variety, position and characteristics of the stubble height

Abstract

The application provides a kind of regeneration rice cultivation method of matching stubble height according to variety node characteristics, and relates to the technical field of rice regeneration cultivation.The cultivation method first divides the tested variety into high node regeneration bud dominant type and low node regeneration bud dominant type according to the node characteristics of variety regeneration seedling;when harvesting in the first season, the high node type variety retains the second node as the standard, and the low node type variety retains the third node as the standard.Meanwhile, the synergistic application of bud promoting fertilizer and seedling promoting fertilizer is coupled.The application accurately matches the variety type and stubble height, and cooperates with the synergistic regulation of key fertilizer, effectively solves the regeneration seedling conflict of different node dominant varieties, realizes the synergistic improvement of regeneration season group ear layer uniformity and yield, has the characteristics of simple operation, strong applicability, stable yield and high yield, and is suitable for large-scale popularization and application in the regeneration rice planting area of the middle and lower reaches of the Yangtze River.

Description

Technical Field

[0001] This invention relates to the field of rice regeneration cultivation technology, and in particular to a method for regenerating rice cultivation that matches the stubble height according to the node characteristics of the variety. Background Technology

[0002] Ratoon rice refers to a planting pattern where, after the first rice harvest, dormant buds (regenerated buds) on the rice stubble sprout, grow, and produce grains, resulting in a second harvest of rice (ratoon rice). It is also known as "one crop, two harvests." This pattern offers advantages such as a short growing season, low labor intensity, high annual yield, superior rice quality, and good ecological benefits. In recent years, it has gradually developed into an important cultivation model for maximizing rice production in southern rice-growing areas such as the middle and lower reaches of the Yangtze River in my country.

[0003] To promote stable and increased yields of ratooning rice, a relatively common cultivation paradigm has been established in this field. This includes selecting varieties with ratooning capabilities, harvesting the first crop at nine-tenths maturity, controlling the stubble height to be between 20-35cm, and applying nitrogen fertilizer such as bud-promoting fertilizer after the first crop has fully headed and topdressing with seedling fertilizer after harvest. The industry generally believes that increasing the stubble height to increase the number of retained buds, combined with increased nitrogen fertilizer application, will promote more ratooning seedlings and larger panicles, and that as long as the total number of ratooning seedlings is guaranteed, high yields can be achieved.

[0004] However, despite the aforementioned conventional measures improving ratooning yields to some extent, large-scale ratooning rice production still faces the prominent problem of significant interannual yield fluctuations. On the one hand, while there are numerous rice varieties on the market, the vast majority have low and unstable ratooning yields, making them unsuitable for ratooning cultivation. On the other hand, there are significant differences in ratooning characteristics among high-yielding ratooning rice varieties, and the germination ability of regenerated buds and the maturity of regenerated panicles vary across different nodes within the same variety, greatly limiting the realization of yield potential. Currently, ratooning rice varieties widely planted in production can be divided into two categories based on dominant node differences: high-node dominance and low-node dominance. The former has a higher panicle formation rate from the second-to-last node regenerated bud, while the latter has a higher panicle formation rate from the third-to-last node or lower. In cultivation management, stubble height and nitrogen fertilizer management are crucial factors affecting the germination of regenerated buds at different nodes, the development of regenerated panicles, and the overall yield of ratooning rice.

[0005] In view of this, it is necessary to design an improved method for cultivating ratooning rice that matches the stubble height according to the node characteristics of the variety in order to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a method for cultivating ratooning rice by matching the stubble height according to the node characteristics of the variety.

[0007] To achieve the above-mentioned objectives, in a first aspect, the present invention provides a method for cultivating ratooning rice by matching the stubble height according to the node characteristics of the variety, comprising the following steps:

[0008] S1. High-node regeneration bud dominant varieties and low-node regeneration bud dominant varieties are used as breeding varieties. Sowing is carried out from early to mid-March each year, and transplanting is carried out in a timely manner. The high-node dominant rice variety is Longjingyou 1212, and the low-node dominant rice variety is Yongyou 4949.

[0009] S2. Irrigate promptly after transplanting in the first season to promote greening, dry the field during the mid-tillering stage, re-irrigate during the second stage of young panicle differentiation, and irrigate alternately with dry and wet irrigation after heading, draining the water one week before harvest; the total nitrogen fertilizer application rate for the first season is 180-225 kg·N / hm. 2 The total application rate of phosphate fertilizer is 90-110 kg·P₂O₅ / hm² 2 The total application rate of potassium fertilizer is 90-110 kg·K2O / hm. 2 ;

[0010] S3. Harvest when the first crop is nine-tenths mature. Determine the stubble height based on the node height of the dominant bud. After harvesting, maintain soil moisture by irrigating at night and draining during the day. Once the regenerated buds have grown to over 10 cm, irrigate deeply. Stop watering one week before harvesting. The total nitrogen fertilizer application rate during the regeneration season is 100-175 kg·N / hm². 2 ;

[0011] S4. Harvest ratooning rice at the yellow ripening stage. During the entire growth cycle of the first-season to ratooning rice, spray pesticides once each at the peak tillering stage, heading stage, and seedling stage of the ratooning season to control pests and diseases.

[0012] Preferably, in step S3, during the first harvest, the stubble height for high-node regenerated bud dominant varieties is based on retaining the second node from the top, and the stubble height for low-node regenerated bud dominant varieties is based on retaining the third node from the top. The second and third nodes from the top refer to the axillary buds of the second and third nodes of the main stem counted sequentially downwards from the panicle neck node during the first harvest of rice.

[0013] Preferably, in step S3, during the first harvest, the stake height of Longjingyou 1212 is 40 cm and the stake height of Yongyou 4949 is 15 cm.

[0014] Preferably, in step S1, the sowing time is from March 5 to March 20.

[0015] Preferably, in step S2, nitrogen fertilizer is allocated in a 5:3:2 ratio according to the total application amount and applied as base fertilizer, tillering fertilizer and heading fertilizer respectively; phosphorus fertilizer is applied entirely as base fertilizer; and potassium fertilizer is allocated in a 1:1 ratio according to the total application amount and applied as base fertilizer and heading fertilizer respectively.

[0016] Preferably, in step S2, the tillering fertilizer is applied 10 days after transplanting, and the panicle fertilizer is applied during the second stage of panicle differentiation.

[0017] Preferably, in step S3, the application rate of the bud-promoting fertilizer is determined based on leaf color within 15-20 days after the first heading of the crop, and the application rate does not exceed 75 kg·N / hm. 2 Urea is used as a fertilizer to promote bud growth.

[0018] Preferably, in step S3, 100 kg N / hm² of urea is applied as a top dressing within 3 days after the first harvest. 2 Use it as fertilizer for seedlings.

[0019] Secondly, this invention provides a method for cultivating ratooning rice and its application in the large-scale cultivation of ratooning rice in the middle and lower reaches of the Yangtze River.

[0020] The beneficial effects of this invention are:

[0021] The ratooning rice cultivation method provided by this invention precisely targets the second bud from the top of the high-node type and the third bud from the top of the low-node type as the main panicle-forming units by matching the stubble height according to the different sprouting characteristics of the variety nodes. This reduces the panicle layer disorder caused by the difference in the sprouting time of buds at different nodes from the perspective of population construction. At the same time, it physiologically couples the stubble height with the application window of the sprouting fertilizer and the seedling fertilizer, so that the nutrient supply is precisely matched with the differentiation and seedling stage of the target dominant buds. This avoids the ineffective competition and consumption of nutrients by inferior buds, and solves the contradiction that simply increasing nitrogen fertilizer to induce the sprouting of weak buds will reduce the quality of the population. Ultimately, it achieves a synergistic breakthrough in the uniformity of panicle development and yield potential in the ratooning season. Attached Figure Description

[0022] Figure 1 This describes the growth of internodes and regenerated buds of the stems of Longjingyou 1212 and Yongyou 4949 in Example 1 of this invention.

[0023] Figure 2 The comparison results of the internode (I2-I5) lengths of Longjingyou 1212 and Yongyou 4949 before the first harvest in Example 1 of the present invention;

[0024] Figure 3 This is a dynamic change diagram of the number of regenerated buds surviving in Longjingyou 1212 and Yongyou 4949 under different stubble heights and nitrogen fertilizer treatments in Example 1 of the present invention.

[0025] Figure 4 The correlation between the yield of ratooned rice and panicle uniformity in Example 1 of the present invention;

[0026] Figure 5 This is a comparison of the internode (I2-I5) lengths of Longjingyou 1212 and Yongyou 4949 before the first harvest in Example 2 of the present invention;

[0027] Figure 6 This is a dynamic change graph showing the number of regenerated buds surviving in Longjingyou 1212 and Yongyou 4949 under different stubble heights and nitrogen fertilizer treatments in Example 2 of the present invention.

[0028] Figure 7 The correlation between the yield of regenerated rice and panicle uniformity of Longjingyou 1212 and Yongyou 4949 in Example 2 of this invention is shown. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] It should also be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0031] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0032] This invention provides a method for cultivating ratooning rice by matching the stubble height according to the node characteristics of the variety, comprising the following steps:

[0033] S1. High-node regeneration bud dominant varieties and low-node regeneration bud dominant varieties are used as breeding varieties. Sowing is carried out from early to mid-March each year. Seedlings are raised in seedbed arched sheds or glass greenhouses to avoid low temperature damage. Transplanting is done in a timely manner.

[0034] S2. Irrigate promptly after transplanting in the first season to promote greening, dry the field during the mid-tillering stage, re-irrigate during the second stage of young panicle differentiation, and irrigate alternately with dry and wet irrigation after heading, draining the water one week before harvest; the total nitrogen fertilizer application rate for the first season is 180-225 kg·N / hm. 2 The total application rate of phosphate fertilizer is 90-110 kg·P2O5 / hm. 2 The total application rate of potassium fertilizer is 90-110 kg·K2O / hm. 2 Nitrogen fertilizer should be applied as basal fertilizer, tillering fertilizer, and heading fertilizer in a 5:3:2 ratio, while phosphorus fertilizer should be applied entirely as basal fertilizer, and potassium fertilizer should be applied as basal fertilizer and heading fertilizer in a 1:1 ratio. The amount of bud-promoting fertilizer should be determined based on leaf color within 15-20 days after the first heading of the crop, and the application rate should not exceed 75 kg N / hm². 2 Urea is used as a fertilizer to promote bud growth.

[0035] S3. Harvest when the first crop is 90% mature. Determine the stubble height based on the node height of the dominant bud. Irrigate promptly after the first harvest, using a night-irrigation-day-drainage method to keep the soil moist. Once the regenerated buds reach over 10 cm in length, deep irrigation can be applied. Except during the heading stage, maintain a water level by alternating wet and dry irrigation. Stop irrigation one week before harvest. Apply urea at 100 kg N / hm² within 3 days after the first harvest. 2 Used as fertilizer for seedlings;

[0036] S4. Harvest ratooning rice at the yellow ripening stage. Strictly control pests and diseases throughout the entire growth cycle of the first-season to ratooning rice. Spray pesticides once each during the tillering peak stage, heading stage, and seedling stage of the ratooning season.

[0037] In some embodiments, in step S1, the high-node dominant rice variety is Longjingyou 1212, and the low-node dominant rice variety is Yongyou 4949.

[0038] In some embodiments, in step S1, the sowing time is from March 5 to March 20, and the seeds need to be water-selected and disinfected before sowing.

[0039] In some embodiments, in step S2, the tillering fertilizer is applied 10 days after transplanting, and the panicle fertilizer is applied during the second stage of panicle differentiation.

[0040] In some embodiments, in step S3, the stubble height is determined according to the variety type during the first harvest. For varieties with high-node regeneration bud dominance, the stubble height is based on retaining the second node from the top. For varieties with low-node regeneration bud dominance, the stubble height is based on retaining the third node from the top. The second and third nodes from the top refer to the axillary buds of the second and third nodes of the main stem counted sequentially downwards from the panicle neck during the first harvest of rice.

[0041] In some embodiments, in step S4, the agent is at least one of propiconazole, tricyclazole, pymetrozine, and chlorantraniliprole, used to control rice sheath blight, rice blast, stem borers, and rice planthoppers.

[0042] The following specific embodiments further illustrate the ratooning rice cultivation method proposed in this invention, which matches the stubble height according to the variety's node characteristics:

[0043] Example 1

[0044] This embodiment provides a method for cultivating ratooning rice by matching the stubble height according to the node characteristics of the variety, including the following steps:

[0045] S1. Select Daxigang Village, Qianshanhong Town, Datonghu District, Yiyang City, Hunan Province as the cultivation site. Use Longjingyou 1212 (a high-node regenerated bud dominant variety) and Yongyou 4949 (a low-node regenerated bud dominant variety) as the cultivation varieties. The first growth period of the two varieties is about 130 days. Sow on March 25, 2024. Place the seedling trays in a greenhouse for heat preservation and seedling cultivation to prevent the seedlings from being damaged by low temperature.

[0046] S2, transplanted on April 19, 2024, with 2 seedlings per hole and a transplanting density of 20 cm × 20 cm. The total amount of nitrogen fertilizer (urea) applied in the first season was 180 kg·N / hm. 2 The total application rate of phosphate fertilizer (superphosphate) is 90 kg P2O5 / hm. 2 The total application rate of potassium fertilizer (potassium chloride) is 90 kg·K2O / hm. 2 Nitrogen fertilizer should be applied 1 day before transplanting (basal fertilizer), 10 days after transplanting (tillering stage), and during the second stage of panicle differentiation, with a nitrogen fertilizer application ratio of 5:3:2. All phosphorus fertilizer should be applied as basal fertilizer in one application. Potassium fertilizer should be applied 1 day before transplanting (basal fertilizer) and during the second stage of panicle differentiation, with a potassium fertilizer application ratio of 1:1. Urea should be applied at 75 kg N / hm² 15 days after the first heading stage. 2 As a fertilizer to promote bud growth (with no fertilizer applied as a control), 100 kg N / hm² of urea was applied within 3 days after the first harvest. 2 As a seedling fertilizer (with no seedling fertilizer as a control).

[0047] S3. From the first transplanting stage to the early tillering stage, maintain a shallow water layer of 2-3 cm to promote tillering. When the number of tillers reaches 80% of the expected number of ears, drain and dry the field. During the second stage of young ear differentiation, re-irrigate and maintain a water layer of 3-5 cm until heading. During the grain filling stage, use alternating wet and dry irrigation. Drain and dry the field 10 days before harvest. On the evening of the first harvest day, re-irrigate using the intermittent re-irrigation method of "irrigating at night and draining in the morning" until the regenerated buds sprout and stabilize. Then maintain the water layer until heading in the regenerated season. During the grain filling stage of the regenerated season, use alternating wet and dry irrigation. Drain and dry the field one week before harvest.

[0048] S4. Harvest manually when the first crop is nine-tenths mature. Set the stubble height for Longjingyou 1212 to 40cm, retaining the second node from the bottom as the regenerated bud. Set the stubble height for Yongyou 4949 to 15cm, retaining the third node from the bottom as the regenerated bud. Harvest manually during the yellow ripening stage of the ratooning rice. Stop watering one week before harvesting and adjust the drainage time according to the weather and soil moisture content to ensure that the soil hardness is sufficient to support the harvesting operation. Strictly control pests and diseases throughout the entire growth cycle of the first crop and ratooning rice. Spray chlorantraniliprole and thifluzamide during the peak tillering stage of the first crop to control stem borers and sheath blight. Spray chlorantraniliprole, tebuconazole / propiconazole, tricyclazole, and trifluralin / pymetrozine during the heading stage to control stem borers, sheath blight, rice false smut, rice blast, and rice planthoppers. Spray trifluralin or pymetrozine again during the seedling stage of the ratooning season to continuously control rice planthopper damage.

[0049] Before the first harvest, 105 single stems were selected from 15 root samples of each of the two varieties and randomly divided into 3 groups to measure the internode lengths (I2, I3, I4, and I5). The stem internode structure and regenerated bud growth of Longjingyou 1212 and Yongyou 4949 were also measured. Figure 1 As shown.

[0050] From 15 days after the first heading to the heading stage of the second heading season, two uniformly growing plants were selected from each plot every 5 days. The regenerated buds / sprouts at the second, third, fourth, and fifth nodes from the top (D2, D3, D4, and D5) were detached from the mother stem. The number of live buds / sprouts at each node was recorded using the following formula:

[0051] Number of regenerated shoots / tillers per unit area = Number of live shoots at each node / tillers (shoot length > 1 cm) / 2 rice clumps covering the area.

[0052] At maturity, 100 plants were randomly sampled from each plot (10 columns in each direction), with an area of ​​4 m². 2 This was used to determine the actual yield. Additionally, 12 representative plants were selected to investigate yield components such as the number of spikes and the number of florets per spike.

[0053] Thirty ears were randomly selected at maturity during the regeneration season. The ear length, ear weight, number of primary branches, and number of secondary branches of Longjingyou 1212 and Yongyou 4949 were measured. Ear uniformity was calculated using the following formula: Where rd represents uniformity, x̄ represents the sample mean, and s represents the standard deviation. The overall evaluation is the average of the four indicators.

[0054] A comparison of the internode (I2-I5) lengths of Longjingyou 1212 and Yongyou 4949 before the first harvest is shown in the following figure. Figure 2 As shown, where Figure 2 Figure (a) in the text corresponds to Longjing You 1212. Figure 2Figure (b) corresponds to Yongyou 4949. The results show that the internode lengths I2, I3, I4, and I5 of Longjingyou 1212 and Yongyou 4949 are 16.12, 10.93, 7.24, 2.46 cm and 12.06, 15.03, 9.38, 2.26 cm, respectively. This indicates that both Longjingyou 1212 and Yongyou 4949 can retain D3, D4, and D5 at a pile height of 15 cm, and can retain D2, D3, D4, and D5 at a pile height of 40 cm.

[0055] The dynamic changes in the number of regenerated shoots surviving under different stubble heights and nitrogen fertilizer treatments for Longjingyou 1212 and Yongyou 4949 are shown in the figure below. Figure 3 As shown, the results indicated that at a stubble height of 40 cm, the number of regenerated buds per unit area during the heading stage of the regeneration season was higher for both varieties than in the 15 cm treatment. The difference was smaller for Longjingyou 1212 and larger for Yongyou 4949. Nitrogen application significantly increased the number of regenerated buds per unit area, and the effect of seedling fertilizer was better than that of bud-promoting fertilizer; the combination of the two yielded the best results.

[0056] The correlation between ratooning rice yield and panicle uniformity is as follows: Figure 4 As shown in the figure, the results indicate that the yield of Longjingyou 1212 and Yongyou 4949 in the regeneration season is significantly positively correlated with the uniformity of the panicle (p<0.01).

[0057] The effects of stubble height and nitrogen fertilizer treatment on the number of panicles per unit area, the number of florets per panicle, and the panicle contribution rate at the 3rd, 4th, and 5th nodes from the bottom (D3, D4, and D5) are shown in Table 1. The results indicate that compared to Longjingyou 1212, Yongyou 4949 has fewer panicles but more grains per panicle. Furthermore, the dominant node of Longjingyou 1212 is the uppermost node, while the dominant node of Yongyou 4949 is the middle and lower nodes. At a stubble height of 40cm, the panicle contribution rate at the D2 node of Longjingyou 1212 is as high as 87.5%; while at a stubble height of 15cm, the combined panicle contribution rate at the D4 and D5 nodes of Yongyou 4949 is as high as 85.1%. Nitrogen fertilizer application increased the number of panicles per unit area at each node to varying degrees, and also increased the number of florets per panicle, but the combined application of bud-promoting fertilizer and seedling fertilizer had the best effect.

[0058] Table 2 shows the uniformity and yield of ears in the regeneration season under different stubble heights and nitrogen fertilizer treatments. Table 1-2 shows that Longjingyou 1212 had the highest yield and ear uniformity in the regeneration season after the first season stubble height was 40 cm and the application of bud-promoting fertilizer and seedling fertilizer. Yongyou 4949 had the highest yield and ear uniformity in the regeneration season after the first season stubble height was 15 cm and the application of bud-promoting fertilizer and seedling fertilizer.

[0059] In Table 1-2, D2, D3, D4, and D5 represent the second, third, fourth, and fifth nodes from the bottom, respectively; N0 indicates that neither bud-promoting fertilizer nor seedling fertilizer is applied; N BThis indicates that the recommended application rate for bud-promoting fertilizer is 75 kg N / ha; N T This indicates that the amount of fertilizer applied for seedling growth is 100 kg N / ha; N B+T The numbers represent the application of 75 kg N / ha for promoting bud growth and 100 kg N / ha for promoting seedling growth. In the same column, different lowercase "ad" letters indicate that the differences in nitrogen fertilizer treatments are significant at the same node position, while different uppercase "AD" letters indicate that the differences in each indicator are significant at different nodes (LSD 0.05).

[0060] Table 1

[0061]

[0062]

[0063]

[0064] Example 2

[0065] This embodiment provides a method for cultivating ratooning rice by matching the stubble height according to the node characteristics of the variety, including the following steps:

[0066] S1. Select Daxigang Village, Qianshanhong Town, Datonghu District, Yiyang City, Hunan Province as the cultivation site. Use Longjingyou 1212 (a high-node regenerated bud dominant variety) and Yongyou 4949 (a low-node regenerated bud dominant variety) as cultivation varieties. The first growth period of the two varieties is about 130 days. Sow on March 22, 2025. Place the seedling trays in a greenhouse for heat preservation and seedling cultivation to prevent the seedlings from being damaged by low temperature.

[0067] S2, transplanted on April 16, 2025, with 2 seedlings per hole and a transplanting density of 20 cm × 20 cm. The total amount of nitrogen fertilizer (urea) applied in the first season was 180 kg N / hm. 2 The total application rate of phosphate fertilizer (P2O5) is 90 kg N / hm. 2 The total application rate of potassium fertilizer (K2O) is 72 kg·N / hm. 2 Nitrogen fertilizer should be applied 1 day before transplanting (basal fertilizer), 10 days after transplanting (tillering stage), and during the second stage of panicle differentiation, with a nitrogen application ratio of 5:3:2. All phosphorus fertilizer should be applied as basal fertilizer in one application. Potassium fertilizer should be applied 1 day before transplanting (basal fertilizer) and during the second stage of panicle differentiation, with a potassium application ratio of 1:1. Urea should be applied at 75 kg N / hm² 15 days after the first heading stage. 2 As a fertilizer to promote bud growth (with no fertilizer applied as a control), the seedling fertilizer was applied at 100 kg N / hm² of urea within 3 days after the first harvest. 2 As a seedling fertilizer (with no seedling fertilizer as a control).

[0068] S3. From the first transplanting stage to the early tillering stage, maintain a shallow water layer of 2-3 cm to promote tillering. When the number of tillers reaches 80% of the expected number of ears, drain and dry the field. During the second stage of young ear differentiation, re-irrigate and maintain a water layer of 3-5 cm until heading. During the grain filling stage, use alternating wet and dry irrigation. Drain and dry the field 10 days before harvest. On the evening of the first harvest day, re-irrigate using the intermittent re-irrigation method of "irrigating at night and draining in the morning" until the regenerated buds sprout and stabilize. Then maintain the water layer until heading in the regenerated season. During the grain filling stage of the regenerated season, use alternating wet and dry irrigation. Drain and dry the field one week before harvest.

[0069] S4. Harvest manually when the first crop is 90% mature, leaving stubble at heights of 15 cm and 40 cm.

[0070] The ratooning rice is harvested manually at the yellow ripening stage. Throughout the entire growth cycle of the first-season to ratooning rice, pests and diseases are strictly controlled. Pesticides are sprayed once each at the tillering peak stage, heading stage, and seedling stage of the ratooning season. The pesticides include propiconazole, tricyclazole, pymetrozine, chlorantraniliprole, etc., to prevent and control rice sheath blight, rice blast, stem borers, and rice planthoppers.

[0071] The effects of stubble height and nitrogen fertilizer treatment on the number of panicles per unit area, the number of florets per panicle, and the panicle contribution rate at the 3rd, 4th, and 5th nodes from the bottom (D3, D4, and D5) are shown in Table 3. The results indicate that compared to Longjingyou 1212, Yongyou 4949 has fewer panicles but more grains per panicle. Furthermore, the dominant node of Longjingyou 1212 is the uppermost node, while the dominant node of Yongyou 4949 is the middle and lower nodes. At a stubble height of 40cm, the panicle contribution rate at the D2 node of Longjingyou 1212 is as high as 65.3%; while at a stubble height of 15cm, the combined panicle contribution rate at the D4 and D5 nodes of Yongyou 4949 is as high as 78.6%. Nitrogen fertilizer application increased the number of panicles per unit area at each node to varying degrees, and also increased the number of florets per panicle, but the combined application of bud-promoting fertilizer and seedling fertilizer had the best effect.

[0072] Table 4 shows the yield and ear uniformity of the regeneration season under different treatments. Longjingyou 1212 had the highest yield and ear uniformity in the regeneration season after the first season stubble height was 40 cm and the application of bud-promoting fertilizer and seedling fertilizer. Yongyou 4949 had the highest yield and ear uniformity in the regeneration season after the first season stubble height was 15 cm and the application of bud-promoting fertilizer and seedling fertilizer.

[0073] The results of the varietal differences in the length of the basal internodes before harvest between Longjingyou 1212 and Yongyou 4949 are as follows: Figure 5As shown, the results indicate that the internode lengths of Longjingyou 1212 and Yongyou 4949 are 18.88, 13.61, 8.23, and 2.92 cm and 14.25, 17.95, 6.34, and 2.61 cm, respectively. Compared with 2024, there are numerical differences in the internode lengths at different positions, but the trend is consistent. Furthermore, both Longjingyou 1212 and Yongyou 4949 can retain D3, D4, and D5 at a stake height of 15 cm, and D2, D3, D4, and D5 at a stake height of 40 cm.

[0074] The dynamic changes in the number of regenerated shoots surviving in Longjingyou 1212 and Yongyou 4949 under different stubble heights and nitrogen fertilizer treatments are shown in the figure below. Figure 6 As shown, the results indicate that the number of regenerated tillers per unit area exhibits a dynamic pattern of first increasing and then decreasing with the progression of the growth period. Under nitrogen fertilizer treatment, the number of regenerated shoots per unit area for both varieties at a 40 cm stubble height was higher than that at 15 cm. Nitrogen application increased the number of regenerated shoots per unit area to varying degrees, with seedling fertilizer showing a better effect than shoot-promoting fertilizer, and the combined application of the two yielded the best results.

[0075] The correlation between the yield of Longjingyou 1212 and Yongyou 4949 in the regeneration season and the uniformity of the ears is as follows: Figure 7 As shown in the figure, the results indicate that the yield of both varieties during the regeneration season is significantly positively correlated with the uniformity of the panicle.

[0076] Table 3

[0077]

[0078]

[0079]

[0080] The cultivation method proposed in this invention achieves a synergistic improvement in panicle uniformity and yield by precisely matching variety type with stubble height and coupling the application of bud-promoting fertilizer and seedling fertilizer. Two years of experimental results show that the high-node regenerated bud dominant variety Longjingyou 1212, under the condition of stubble height of 40 cm and simultaneous application of bud-promoting fertilizer and seedling fertilizer, and the low-node regenerated bud dominant variety Yongyou 4949, under the condition of stubble height of 15 cm and simultaneous application of bud-promoting fertilizer and seedling fertilizer, exhibits the highest uniformity and yield in the ratooning season. This invention is simple to operate, highly applicable, and can significantly improve panicle uniformity and achieve high and stable yields in the ratooning season, making it particularly suitable for large-scale promotion and application in the ratooning rice planting areas of the middle and lower reaches of the Yangtze River.

[0081] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for cultivating ratooning rice by matching the stubble height according to the node characteristics of the variety, characterized in that, Includes the following steps: S1. High-node regeneration bud dominant varieties and low-node regeneration bud dominant varieties are used as breeding varieties. Sowing is carried out from early to mid-March each year, and transplanting is carried out in a timely manner. The high-node dominant rice variety is Longjingyou 1212, and the low-node dominant rice variety is Yongyou 4949. S2. Irrigate promptly after transplanting in the first season to promote greening, dry the field during the mid-tillering stage, re-irrigate during the second stage of young panicle differentiation, and irrigate alternately with dry and wet irrigation after heading, draining the water one week before harvest; the total nitrogen fertilizer application rate for the first season is 180-225 kg·N / hm. 2 The total application rate of phosphate fertilizer is 90-110 kg·P₂O₅ / hm² 2 The total application rate of potassium fertilizer is 90-110 kg·K2O / hm. 2 ; S3. Harvest when the first crop is nine-tenths mature. Determine the stubble height based on the node height of the dominant bud. After harvesting, maintain soil moisture by irrigating at night and draining during the day. Once the regenerated buds have grown to over 10 cm, irrigate deeply. Stop watering one week before harvesting. The total nitrogen fertilizer application rate during the regeneration season is 100-175 kg·N / hm². 2 ; S4. Harvest ratooning rice at the yellow ripening stage. During the entire growth cycle of the first-season to ratooning rice, spray pesticides once each at the peak tillering stage, heading stage, and seedling stage of the ratooning season to control pests and diseases.

2. The method for cultivating ratooned rice according to claim 1, characterized in that, In step S3, during the first harvest, the stubble height for high-node regenerated bud dominant varieties is based on retaining the second node from the top, while the stubble height for low-node regenerated bud dominant varieties is based on retaining the third node from the top. The second and third nodes from the top refer to the axillary buds of the second and third nodes of the main stem counted sequentially downwards from the panicle neck node during the first harvest of rice.

3. The method for cultivating ratooning rice according to claim 1, characterized in that, In step S3, during the first harvest, the stubble height of Longjingyou 1212 is 40 cm, and the stubble height of Yongyou 4949 is 15 cm.

4. The method for cultivating ratooned rice according to claim 1, characterized in that, In step S1, the sowing period is from March 5 to March 20.

5. The method for cultivating ratooning rice according to claim 1, characterized in that, In step S2, nitrogen fertilizer is allocated in a 5:3:2 ratio according to the total amount applied, and is applied as base fertilizer, tillering fertilizer and heading fertilizer respectively. Phosphorus fertilizer is applied entirely as base fertilizer. Potassium fertilizer is allocated in a 1:1 ratio according to the total amount applied, and is applied as base fertilizer and heading fertilizer respectively.

6. The method for cultivating ratooning rice according to claim 1, characterized in that, In step S2, the tillering fertilizer is applied 10 days after transplanting, and the panicle fertilizer is applied during the second stage of panicle differentiation.

7. The method for cultivating ratooning rice according to claim 1, characterized in that, In step S3, the application rate of the bud-promoting fertilizer is determined based on leaf color within 15-20 days after the first heading of the crop, and the application rate should not exceed 75 kg·N / hm. 2 Urea is used as a fertilizer to promote bud growth.

8. The method for cultivating ratooning rice according to claim 1, characterized in that, In step S3, apply 100 kg N / hm² of urea as a top dressing within 3 days after the first harvest. 2 Use it as fertilizer for seedlings.

9. The method for cultivating ratooning rice according to claim 1, characterized in that, In step S4, the agent is at least one of propiconazole, tricyclazole, pymetrozine, and chlorantraniliprole.

10. The application of a method for cultivating ratooning rice as described in any one of claims 1-9 in the large-scale cultivation of ratooning rice in the middle and lower reaches of the Yangtze River.

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