A pruning method for in-plant rotation felling of mulberry trees used for fruit in cold regions

Abstract

The present invention relates to a pruning method for in-plant rotation of cold-region fruit mulberry trees, belonging to the technical field of fruit tree cultivation. The method comprises the steps of determining the planting period and density of cold-region fruit mulberry trees, the planting method, shaping the basic tree shape, and annual rotation pruning. This method can increase the fruit yield of cold-region fruit mulberry trees by 2-3 times, and the fruiting part of the tree will not shift upwards year by year, facilitating manual or mechanical harvesting. The number of fruiting branches is relatively constant each year, ensuring that the annual yield remains stable within a relatively fixed range and preventing the occurrence of alternate years. The fruiting branches are renewed annually, resulting in fewer major wounds after pruning, minimal damage to the tree, and the vitality of the tree can be maintained, making it strong and less susceptible to disease.

Description

Technical Field

[0001] The invention belongs to the technical field of fruit tree cultivation, and in particular relates to a pruning method for in-plant rotation felling of mulberry trees used for fruit in cold regions. Background Art

[0002] In southern regions, mulberry trees are pruned after fruiting each year. This allows new branches to fully lignify and complete flower bud differentiation that same year, allowing them to safely overwinter without affecting growth and fruiting the following year. The entire fruiting branch group, after pruning, resembles a fist, a practice known as fist pruning. However, in cold regions, fruiting mulberry trees fruit from mid-June to mid-July. If pruning is done after fruiting, before winter frost and leaf drop, branches will grow very little, only 20 to 70 cm, and will not fully lignify. Leaf and flower buds will not mature, preventing them from safely overwintering. They will not sprout or bloom the following year, and may even die. Therefore, the southern practice of pruning after fruiting should not be used in cold regions.

[0003] Traditionally, cold-region mulberry trees have employed the same pruning methods used for other types of fruit trees, such as open-heart and main-trunk trees. This involves annually pruning 1 / 2 to 2 / 3 of the annual branches. This method shifts the fruiting area upwards, lengthening the nutrient transport path and increasing nutrient consumption. This leaves the lower part of the tree bare, leafless, and photosynthetic, resulting in weak growth. Furthermore, annual pruning of the annual branches reduces yield by 1 / 2 to 2 / 3. Therefore, finding a pruning method that optimizes the growth characteristics of cold-region mulberry trees and increases fruit yield is crucial. Summary of the Invention

[0004] The purpose of the method of the present invention is to address the above-mentioned existing problems and, in combination with the actual needs of mulberry cultivation operations in the high-altitude Heilongjiang region, develop a pruning method for cold-region fruit mulberry trees by intra-plant rotation felling, so as to achieve the purpose of increasing the fruit yield of cold-region fruit mulberry trees.

[0005] The object of the present invention is achieved in that the pruning method of cold-region fruit mulberry tree in-plant rotation felling comprises:

[0006] A pruning method for in-plant rotation felling of mulberry trees used for fruit in cold regions comprises the following steps:

[0007] (1) Planting period and density: Plant before budding in spring, with rows oriented north-south, with a row spacing of 3-4 meters and a plant spacing of 3 meters;

[0008] (2) Planting method:

[0009] a. Digging a tree hole: Dig a hole with a length, width and depth of 30 to 40 cm. The width of the hole should be the same from top to bottom, and the soil at the bottom should be loose.

[0010] b. Apply base fertilizer: apply 1-2 kg of decomposed manure and 200-300 g of nitrogen, phosphorus and potassium compound fertilizer, and mix them evenly with the bottom soil;

[0011] c. Before planting, prune the roots of one-year-old mulberry trees so that the roots can stretch naturally in the tree hole without bending;

[0012] d. When planting, make sure the grafting point of the mulberry tree is below the soil layer, and the junction of the green and yellow rhizomes is level with the soil layer;

[0013] e. After filling the soil, tamp it down and make the upper edge of the soil in the tree hole 5 to 7 cm below the soil layer to facilitate watering;

[0014] f. Water the plants on the same day after planting, and irrigate thoroughly at one time;

[0015] (3) The basic shape of the cold-region fruit mulberry tree should be formed in the first three years of planting:

[0016] a. The first year: After planting and before germination, the stems are fixed. In order to facilitate the passage of machinery, the height of the fixed stems is selected to be 60 to 100 cm according to the height of the tractor used. The horizontal height of the fixed stems in the same plot is consistent. In summer, when the new shoots grow to 10 to 15 cm, 3 to 4 new shoots with strong growth and uniform growth position on the upper part of the main trunk are selected. The growth angle of the selected new shoots is tilted upward and the angle with the horizontal is 30° to 75°. The rest are thinned out. 3 to 4 main branches are cultivated in the same year.

[0017] b. Second year: Before budding, cut back the main branches grown in the first year at 40-50 cm from the base of the branches, and remove the remaining branches. In summer, when the new shoots grow to 10-15 cm, select 2-3 new shoots that grow strong and evenly located on the upper part of the main branches as side branches. The selected new shoots should grow upward at an angle of 30°-75° to the horizontal, and remove the remaining ones. In that year, the tree should have a total of 6-9 side branches.

[0018] c. The third year: Before budding, the side branches developed in the second year are cut back at 40 to 50 cm from the base of the branches, and the remaining branches are thinned out. In summer, when the new shoots grow to 10 to 15 cm, 6 to 7 strong new shoots on the upper part of the side branches are selected as fruiting branches and renewal branches. The selected new shoots grow at an upward angle and at an angle of 15° to 80° to the horizontal. The rest are thinned out. In that year, a total of 30 to 40 one-year-old branches are cultivated on the tree as fruiting branches and renewal branches, and the basic tree shape is completed;

[0019] (4) From the fourth year onwards, the pruning method of intra-plant rotation is implemented, with branches growing on a side branch as a group, and they are pruned in rotation throughout the year:

[0020] a. Before budding, select two one-year-old branches on a group of side branches that are located lower and in opposite directions, retain 3 to 5 buds and cut them short as renewal branches for the second year's fruiting branches. The remaining 4 to 5 one-year-old branches are used as fruiting branches, with only the stems cut off and thrown out for fruiting;

[0021] b. In summer, when the new shoots grow to 10-15 cm, select 2-3 branches from each renewal branch as the fruiting branches for the next year, and remove the rest;

[0022] c. Before budding in the second year, remove the two-year-old branches that were set aside for fruiting the previous year, select two branches that are located lower and in opposite directions, and keep 3 to 5 buds to be pruned as renewal branches for the third-year fruiting branches. Remove the rest. After the previous year's pruning, only the stems of the newly grown one-year-old branches are cut off and set aside for fruiting.

[0023] d. In summer, when the new shoots grow to 10-15 cm, select 2-3 as the fruiting branches for the next year and remove the rest;

[0024] e. Repeat this process to carry out annual rotation pruning within the plant. DETAILED DESCRIPTION

[0025] The embodiments of the present invention are described in detail below.

[0026] A pruning method for in-plant rotation felling of mulberry trees used for fruit in cold regions comprises the following steps:

[0027] (1) Planting period and density: Plant before budding in spring, with rows oriented north-south, with a row spacing of 3-4 meters and a plant spacing of 3 meters;

[0028] (2) Planting method:

[0029] a. Digging a tree hole: Dig a hole with a length, width and depth of 30 to 40 cm. The width of the hole should be the same from top to bottom, and the soil at the bottom should be loose.

[0030] b. Apply base fertilizer: apply 1-2 kg of decomposed manure and 200-300 g of nitrogen, phosphorus and potassium compound fertilizer, and mix them evenly with the bottom soil;

[0031] c. Before planting, prune the roots of one-year-old mulberry trees so that the roots can stretch naturally in the tree hole without bending;

[0032] d. When planting, make sure the grafting point of the mulberry tree is below the soil layer, and the junction of the green and yellow rhizomes is level with the soil layer;

[0033] e. After filling the soil, tamp it down and make the upper edge of the soil in the tree hole 5 to 7 cm below the soil layer to facilitate watering;

[0034] f. Water the plants on the same day after planting, and irrigate thoroughly at one time;

[0035] (3) The basic shape of the cold-region fruit mulberry tree should be formed in the first three years of planting:

[0036] a. The first year: After planting and before germination, the stems are fixed. In order to facilitate the passage of machinery, the height of the fixed stems is selected to be 60 to 100 cm according to the height of the tractor used. The horizontal height of the fixed stems in the same plot is consistent. In summer, when the new shoots grow to 10 to 15 cm, 3 to 4 new shoots with strong growth and uniform growth position on the upper part of the main trunk are selected. The growth angle of the selected new shoots is tilted upward and the angle with the horizontal is 30° to 75°. The rest are thinned out. 3 to 4 main branches are cultivated in the same year.

[0037] b. Second year: Before budding, cut back the main branches grown in the first year at 40-50 cm from the base of the branches, and remove the remaining branches. In summer, when the new shoots grow to 10-15 cm, select 2-3 new shoots that grow strong and evenly located on the upper part of the main branches as side branches. The selected new shoots should grow upward at an angle of 30°-75° to the horizontal, and remove the remaining ones. In that year, the tree should have a total of 6-9 side branches.

[0038] c. The third year: Before budding, the side branches developed in the second year are cut back at 40 to 50 cm from the base of the branches, and the remaining branches are thinned out. In summer, when the new shoots grow to 10 to 15 cm, 6 to 7 strong new shoots on the upper part of the side branches are selected as fruiting branches and renewal branches. The selected new shoots grow at an upward angle and at an angle of 15° to 80° to the horizontal. The rest are thinned out. In that year, a total of 30 to 40 one-year-old branches are cultivated on the tree as fruiting branches and renewal branches, and the basic tree shape is completed;

[0039] (4) From the fourth year onwards, the pruning method of intra-plant rotation is implemented, with branches growing on a side branch as a group, and they are pruned in rotation throughout the year:

[0040] a. Before budding, select two one-year-old branches on a group of side branches that are located lower and in opposite directions, retain 3 to 5 buds and cut them short as renewal branches for the second year's fruiting branches. The remaining 4 to 5 one-year-old branches are used as fruiting branches, with only the stems cut off and thrown out for fruiting;

[0041] b. In summer, when the new shoots grow to 10-15 cm, select 2-3 branches from each renewal branch as the fruiting branches for the next year, and remove the rest;

[0042] c. Before budding in the second year, remove the two-year-old branches that were set aside for fruiting the previous year, select two branches that are located lower and in opposite directions, and keep 3 to 5 buds to be pruned as renewal branches for the third-year fruiting branches. Remove the rest. After the previous year's pruning, only the stems of the newly grown one-year-old branches are cut off and set aside for fruiting.

[0043] d. In summer, when the new shoots grow to 10-15 cm, select 2-3 as the fruiting branches for the next year and remove the rest;

[0044] e. Repeat this process to carry out annual rotation pruning within the plant.

[0045] Using this method, fruiting mulberry trees produce 2-3 times more fruit than before. The fruiting area does not shift upward year by year, remaining at a constant level of 1.5-2.5 meters, making it easier to harvest manually or mechanically. The number of fruiting branches remains relatively constant each year, ensuring stable yields within a relatively fixed range and reducing the risk of uneven yields. Fruiting branches are renewed annually, resulting in fewer major pruning wounds and minimal damage to the tree, maintaining its vitality and making it stronger and less susceptible to disease.

[0046] Figure 1 is a comparison of annual mulberry yields using the method of the present invention and the conventional method.

[0047] As shown in Figure 1, the average yield of mulberries using the patented intra-plant rotation pruning method is 2.45 times that of the ordinary pruning method.

[0048] The method of the present invention is more advantageous.

[0049] Table 1 Comparison of the results of the method of the present invention and the conventional method:

[0050]

[0051] As shown in Table 1, the patented intra-plant rotation pruning method maintains a stable fruiting position at 1.5 to 2.5 meters, whereas conventional pruning methods cause the fruiting position to move upward year by year, resulting in high nutrient consumption and inconvenience during harvesting. This demonstrates the advantages of the patented method.

Claims

1. A method for pruning mulberry trees for fruit cultivation in cold regions by rotational felling, comprising the following steps: (1) Planting period and density: Plant before budding in spring, with rows oriented north-south, with a row spacing of 3-4 meters and a plant spacing of 3 meters; (2) Planting method: a. Digging a tree hole: Dig a hole with a length, width and depth of 30 to 40 cm. The width of the hole should be the same from top to bottom, and the soil at the bottom should be loose. b. Apply base fertilizer: apply 1-2 kg of decomposed manure and 200-300 g of nitrogen, phosphorus and potassium compound fertilizer, and mix them evenly with the bottom soil; c. Before planting, prune the roots of one-year-old mulberry trees so that the roots can stretch naturally in the tree hole without bending; d. When planting, make sure the grafting point of the mulberry tree is below the soil layer, and the junction of the green and yellow rhizomes is level with the soil layer; e. After filling the soil, tamp it down and make the upper edge of the soil in the tree hole 5 to 7 cm below the soil layer to facilitate watering; f. Water the plants on the same day after planting, and irrigate thoroughly at one time; Its characteristics are: (3) The basic shape of the cold-region fruit mulberry tree should be formed in the first three years of planting: a. The first year: After planting and before germination, the stems are fixed. In order to facilitate the passage of machinery, the height of the fixed stems is selected to be 60 to 100 cm according to the height of the tractor used. The horizontal height of the fixed stems in the same plot is consistent. In summer, when the new shoots grow to 10 to 15 cm, 3 to 4 new shoots with strong growth and uniform growth position on the upper part of the main trunk are selected. The growth angle of the selected new shoots is tilted upward and the angle with the horizontal is 30° to 75°. The rest are thinned out. 3 to 4 main branches are cultivated in the same year. b. Second year: Before budding, cut back the main branches grown in the first year at 40-50 cm from the base of the branches, and remove the remaining branches. In summer, when the new shoots grow to 10-15 cm, select 2-3 new shoots that grow strong and evenly located on the upper part of the main branches as side branches. The selected new shoots should grow upward at an angle of 30°-75° to the horizontal, and remove the remaining ones. In that year, the tree should have a total of 6-9 side branches. c. The third year: Before budding, the side branches developed in the second year are cut back at 40 to 50 cm from the base of the branches, and the remaining branches are thinned out. In summer, when the new shoots grow to 10 to 15 cm, 6 to 7 strong new shoots on the upper part of the side branches are selected as fruiting branches and renewal branches. The selected new shoots grow at an upward angle and at an angle of 15° to 80° to the horizontal. The rest are thinned out. In that year, a total of 30 to 40 one-year-old branches are cultivated on the tree as fruiting branches and renewal branches, and the basic tree shape is completed; (4) From the fourth year onwards, the pruning method of intra-plant rotation is implemented, with branches growing on a side branch as a group, and they are pruned in rotation throughout the year: a. Before budding, select two one-year-old branches on a group of side branches that are located lower and in opposite directions, retain 3 to 5 buds and cut them short as renewal branches for the second year's fruiting branches. The remaining 4 to 5 one-year-old branches are used as fruiting branches, with only the stems cut off and thrown out for fruiting; b. In summer, when the new shoots grow to 10-15 cm, select 2-3 branches from each renewal branch as the fruiting branches for the next year, and remove the rest; c. Before budding in the second year, remove the two-year-old branches that were set aside for fruiting the previous year, select two branches that are located lower and in opposite directions, and keep 3 to 5 buds to be pruned as renewal branches for the third-year fruiting branches. Remove the rest. After the previous year's pruning, only the stems of the newly grown one-year-old branches are cut off and set aside for fruiting. d. In summer, when the new shoots grow to 10-15 cm, select 2-3 as the fruiting branches for the next year and remove the rest; e. Repeat this process to carry out annual rotation pruning within the plant.

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