Top grafting method for promoting loquats to blossom and bear fruits in advance

Abstract

The invention provides a top grafting method for promoting loquats to bloom and bear fruits in advance. The inventor takes' Huabai No.1 'or' Huabai No.2 'as scions, takes Huayu seedless No.1 as a stump-head tree species, takes a branch at the middle lower part of a spring shoot which does not vertically grow on the periphery of a crown of a specific adult tree fruiting in successive years and has the diameter of more than or equal to 1 cm as a scion, takes a loquat tree flowering and fruiting in successive years as a stump-head tree, and cuts back and grafts from the position with the height of 0.4-0.6 m of the loquat tree plant; the top-grafted scions grow and develop quickly and can bloom and bear fruits in the current year, and the yield can be achieved in the second year through the cooperation of water-soluble compound fertilizer after germination and leaf development in the flowering stage and MS microelement fertilizer sprayed in the specific time. Compared with a traditional top grafting method, the method is 1-2 years earlier.

Description

Technical Field

[0001] This invention belongs to the field of plant breeding technology, specifically relating to a grafting method for promoting early flowering and fruiting of loquat. Background Technology

[0002] Loquat ( Eriobotrya japonica ) belongs to the Rosaceae family ( Rosaceae Loquat genus ( Eriobotrya Loquat is a perennial subtropical evergreen woody fruit tree. Its fruit is delicate, juicy, and rich in nutrients, containing various nutrients and active substances. It ripens in early summer and has a very high market value. Traditionally, loquat is propagated by seed sowing, a method that results in significant variation in offspring. Since the 1970s, my country has gradually adopted grafting propagation, with high grafting (or simply high grafting) being the main method, suitable for replacing existing varieties. High grafting mainly involves shortening branches or trunks of mature trees that have grown for many years and using other materials as scions for grafting. Compared to planting grafted seedlings, because the grafting position is higher, the rootstock is older, has a more developed root system, and stores more nutrients in the trunk, the scions from high grafting grow faster. High-grafted plants can form a larger crown and flower in a shorter time (generally 2-3 years). Therefore, high-grafted fruit trees can produce fruit within 3-4 years, and within 5 years can reach the same yield as trees planted for 8 years or more. High grafting comes at the cost of sacrificing the yield of the original tree. Although high-position grafting significantly shortens the planting cycle compared to traditional grafting, it still suffers from problems such as long breeding cycles, high breeding costs, and slow variety improvement. Summary of the Invention

[0003] To address the problems in the prior art, this invention provides a grafting method that promotes early flowering and fruiting of loquat.

[0004] The present invention adopts the following technical solution: A high-grafting method to promote early flowering and fruiting of loquat is characterized by high-grafting of loquat after the Rain Water solar term in February. The method involves selecting the lower and middle branches of spring shoots with a diameter ≥1 cm from the outer periphery of mature trees that have fruited for consecutive years. These shoots are then shortened into 4-5 cm stem segments, with long and short oblique cuts to form scions. Loquat trees that have flowered and fruited for consecutive years are selected as rootstocks, and the rootstocks are shortened at a height of 0.4-0.6 m. Grafting is performed using the conventional cleft grafting method. 28-32 days after grafting, once the scions have sprouted and developed leaves, approximately 0.75-1 kg of water-soluble compound fertilizer is applied to the roots of each tree. For 3-6 months after grafting, MS micronutrient fertilizer is sprayed on the leaves monthly. During the flowering period, 0.75-1 kg of water-soluble compound fertilizer is applied to the roots per tree.

[0005] In one embodiment of the present invention, the mature tree bearing fruit year after year is a loquat tree that is 8 years or older.

[0006] In one embodiment of the present invention, the water-soluble compound fertilizer has an N:P:K ratio of 15:15:15 by mass.

[0007] In one embodiment of the present invention, MS micronutrient fertilizer is sprayed once a month for 3-6 months after grafting.

[0008] In one embodiment of the present invention, the spikelet is a 'Huabai No. 1' or 'Huabai No. 2' loquat.

[0009] In one embodiment of the present invention, the tree at the stump is a 'Huayu Seedless No. 1' loquat. Beneficial effects

[0010] As is well known, top grafting comes at the cost of sacrificing the yield of the original tree. Top-grafted plants can develop a larger canopy and flower in a shorter period (generally 2-3 years). Through long-term practice, the inventors discovered that in the process of top grafting loquat, the type of scion and nutrient management have a significant impact on the development and flowering time of the grafted plant. Surprisingly, the inventors used the lower and middle branches of spring shoots with a diameter ≥1 cm from the outer periphery of the canopy of specific mature trees of 'Huabai No. 1' or 'Huabai No. 2' that have been bearing fruit for many years as scions, and used loquat trees that have been flowering and fruiting for many years as stump trees. They grafted the scions at a height of 0.4-0.6m from the loquat tree, supplemented by water-soluble compound fertilizer after budding and leaf development and during the flowering period, as well as MS micronutrient fertilizer sprayed at specific times. This resulted in rapid growth and development of the top-grafted scions, enabling them to flower and bear fruit in the same year and produce yield in the second year. For 'Huabai No. 1', 85% of the grafted plants had inflorescences in the first year, and all plants had inflorescences in the second year; the proportion of scions with inflorescences in the first year was 79.25%, reaching 100% in the second year; the proportion of inflorescences on the total branches in the first year was 41.83±19.62%, reaching 84.26±9.77% in the second year. For 'Huabai No. 2', 75% of the grafted plants had inflorescences in the first year, and all plants had inflorescences in the second year; the proportion of scions with inflorescences in the first year was 82.98%, reaching 100% in the second year; the proportion of inflorescences on the total branches in the first year was 44.79±12.29%, reaching 84.41±8.41% in the second year. Compared with the traditional high grafting method, this is 1-2 years earlier.

[0011] This invention selects specific branches as scions, namely the lower and middle branches of the spring shoots that emerged in the previous year, and uses root application of water-soluble fertilizer and foliar spraying of trace elements to promote rapid growth and development of the scions. They can flower in the autumn of the same year, and the flowering rate of the terminal branches reaches more than 80% in the second year, thus generating yield. This significantly shortens the yield recovery time of high-position grafting of loquat and is of great significance for the replacement of loquat varieties. Attached Figure Description

[0012] Figure 1 These are pictures of some grafted plants that flowered and tested for fruit in the autumn of the same year. In the picture, A shows the branches of 'Huabai No. 2' that have flowered in the same year of grafting, and B shows the terminal branches of the second year with a flowering rate of over 80%. Detailed Implementation

[0013] To further illustrate the present invention and its advantages, specific embodiments are provided below to further explain the technical solution of the present invention. It should be understood that these embodiments are only helpful in understanding the present invention and should not be regarded as specific limitations of the present invention. Unless otherwise specified, all parts mentioned in the present invention are parts by weight, and all percentages are mass percentages.

[0014] In this invention, MS micronutrients (Murashige and Skoog Micronutrients) are one of the commonly used nutrients in plant tissue culture. First proposed by Murashige and Skoog in 1962, they have been widely used in plant cell culture media. The main components of the MS micronutrient mixture include: iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), boron (B), molybdenum (Mo), and cobalt (Co). Example 1

[0015] A grafting method to promote early flowering and fruiting of loquat Loquat breeding case studies: 'Huabai No. 1' and 'Huabai No. 2' Implementation Location: Group 4, Huinan Community, Sanhe Street, Fengdu County, Chongqing Grafting time: February 2022, after the Rain Water solar term.

[0016] Scion selection and treatment: For 'Huabai No. 1' and 'Huabai No. 2', the main scions are the spring shoots from the previous year. Select the lower and middle branches of spring shoots with relatively dense internodes and a diameter of over 1 cm from the outer periphery of mature trees that have fruited for consecutive years (generally over 8 years old). Using conventional methods, the scions are cut into stem segments of approximately 4 cm, with both long and short slant cuts.

[0017] Selection and treatment of stump trees: Trees that have been planted for more than 5 years and have flowered and fruited every year are selected as stump trees. In this example, the stump (Huayu Seedless No. 1) is cut off at a height of 0.4 m.

[0018] Grafting and Post-Grafting Management Grafting is performed using the conventional cleft grafting method. About 30 days after grafting, when the scion sprouts and develops leaves, apply about 0.75-1 kg of water-soluble compound fertilizer (N:P:K=15:15:15) to the roots of each plant in March. From March to June, spray the leaves with MS micronutrients (1×) monthly. During the flowering period, apply water-soluble fertilizer to the roots once, about 0.75-1 kg of water-soluble compound fertilizer (N:P:K=15:15:15) to the roots of each plant.

[0019] Effect: The grafting survival rate reached over 90%, and some plants flowered and began to bear fruit in the autumn of the same year they were grafted, reaching full production in 2-3 years. Figure 1 ).

[0020] 1. Huabai No. 1: 85% of the plants had inflorescences in the year of grafting, and all plants had inflorescences in the second year; the proportion of scions with inflorescences in the year of grafting was 79.25%, and reached 100% in the second year; the proportion of inflorescences in the year of grafting to the total number of terminal branches (4.90±1.19) was 41.83±19.62%, and the proportion of inflorescences in the second year to the total number of terminal branches (13.70±3.65) was 84.26±9.77%.

[0021] 2. Huabai No. 2: 75% of the plants had inflorescences in the year of grafting, and all plants had inflorescences in the second year; the proportion of scions with inflorescences in the year of grafting was 82.98%, and reached 100% in the second year; the proportion of inflorescences in the year of grafting to the total number of terminal branches (4.70±1.25) was 44.79±12.29%, and the proportion of inflorescences in the second year to the total number of terminal branches (16.70±2.21) was 84.41±8.41%.

Claims

1. A grafting method for promoting early flowering and fruiting of loquat, characterized in that, After the Rain Water solar term in February, loquats are grafted at a high position. Select the lower and middle branches of spring shoots with a diameter ≥1 cm from the outer periphery of mature trees that have fruited for consecutive years. Cut the shoots into 4-5 cm stem segments, creating long and short slant cuts to form scions. Select loquat trees that have flowered and fruited for consecutive years as rootstocks, cutting them back to a height of 0.4-0.6 m. Graft using the conventional cleft grafting method. 28-32 days after grafting, once the scions sprout leaves, apply approximately 0.75-1 kg of water-soluble compound fertilizer to the roots of each tree. For 3-6 months after grafting, spray MS micronutrient fertilizer on the leaves monthly. During the flowering period, apply 0.75-1 kg of water-soluble compound fertilizer per tree to the roots.

2. The method as described in claim 1, characterized in that, The mature trees that bear fruit year after year are loquat trees that are 8 years or older.

3. The method as described in claim 1, characterized in that, The water-soluble compound fertilizer has an N:P:K ratio of 15:15:15, by mass.

4. The method as described in claim 1, characterized in that, Apply MS micronutrient fertilizer once a month for 3-6 months after grafting.

5. The method according to any one of claims 1-4, characterized in that, The spikelets are Huabai No. 1 or Huabai No. 2 loquats.

6. The method according to any one of claims 1-4, characterized in that, The tree at the stump is Huayu Seedless No. 1 loquat.

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