Pruning method for promoting blackberry fruiting under outdoor efficient cultivation condition

Abstract

The invention discloses a pruning method for promoting blackberry fruiting under an open field efficient cultivation condition, which is used for performing the following pruning management on the blackberries cultivated in the open field in winter after fruits are harvested: (1) pruning basal branches: for the basal branches of the blackberries, selecting 1-2 branches with the branch thickness of more than 20mm, reserving 1-2 branches as trunks, and directly pruning and removing the rest basal branches; (2) secondary lateral branch pruning: retaining 4-5 secondary lateral branches with the thickness of more than 10 mm and the length of more than 80 cm on the basal branches, pruning and removing all the other secondary branches, pruning the retained secondary lateral branches, and controlling the length between 70 cm and 80 cm; 15-20 tertiary lateral branches with the thickness being 7 mm or above and the length being 50 cm or above on the secondary lateral branches are reserved, moderate pruning is conducted on the tertiary lateral branches, the length is controlled to range from 45 cm to 50 cm, 3-5 axillary buds are reserved on each branch, and the other tertiary lateral branches are directly pruned and removed. According to the method, the blackberries cultivated in the open field are pruned in winter, meanwhile, fertilizer and water regulation in spring and summer of the next year is combined, the balance between vegetative growth and reproductive growth of the blackberries can be effectively regulated, flower bud differentiation of the blackberries is promoted, the number and quality of blackberry fruits are improved, and the maximum economic benefits are achieved.

Description

Technical Field

[0001] The invention belongs to the field of fruit tree cultivation, and in particular relates to an open-field cultivation and pruning method for promoting fruiting of blackberries over two years old. Background Art

[0002] Blackberry is a genus of the Rosaceae family (Rubus Rubus Blackberries are an important small berry tree. Their fruits are highly nutritious, rich in anthocyanins, polyphenols, ellagic acid, and other antioxidant compounds. Traditional cultivation methods no longer meet the demand for blackberries. In large-scale blackberry cultivation, effectively promoting their growth, improving their yield and quality, and maximizing their economic output are pressing challenges.

[0003] As a small shrub fruit tree, blackberry trees grow rapidly, with numerous leggy branches and unclear tiers. Uncontrolled growth often results in overcrowding, a dense canopy that blocks light, leading to inefficient nutrient consumption and disrupting the balance between reproductive and vegetative growth. This is detrimental to fruit development and quality, and can also affect the quality of flower buds the following year. In recent years, due to labor shortages and rising labor costs, blackberry cultivation has been largely managed in a haphazard manner. Infrequent or inappropriate pruning often leads to excessive vigor or premature decline, low and unstable yields, high operating costs, and poor economic returns, hindering the healthy and sustainable development of the blackberry industry. Pruning is a crucial technique for cultivating high-yielding and stable yields in blackberries. Appropriate shaping and pruning of blackberry trees ensures an optimal tree size within a given planting density, maximizes canopy ventilation and photosynthetic capacity, reduces ineffective transpiration, improves water and fertilizer use efficiency, stimulates the growth of flower buds, and effectively improves blackberry yield and quality. Therefore, how to develop a pruning method that can promote blackberry fruiting and increase its yield has become a key technical issue that needs to be solved urgently. Summary of the Invention

[0004] The purpose of the present invention is to solve the defects in the prior art and provide a method that can effectively promote blackberry fruiting and increase blackberry yield, and a cultivation method with very high economic benefits.

[0005] In order to achieve the above object, the present invention is as follows: A pruning method for promoting blackberry fruiting under open-field high-efficiency cultivation conditions, wherein the blackberry plants are pruned as follows in mid-November after the fruit is harvested: (1) Basal branch pruning: For the basal branches of blackberries, select 1 to 2 branches with a thickness of more than 20 mm and retain them as the main trunk. The rest of the basal branches are directly pruned and removed. (2) Pruning of secondary side branches (branches sprouting from the main trunk): retain 4 to 5 secondary side branches on the basal branches with a diameter of more than 10 mm and a length of more than 80 cm, and remove all other secondary branches. At the same time, prune the retained secondary side branches to a length of 70 cm to 80 cm. (3) Pruning of tertiary branches (branches sprouting from secondary branches): retain 15 to 20 tertiary branches with a thickness of more than 7 mm and a length of more than 50 cm on the secondary branches, and prune the tertiary branches moderately, controlling the length between 45 and 50 cm. Keep 3 to 5 axillary buds on each branch, and directly prune away the remaining tertiary branches.

[0006] The pruning method of the present invention is carried out in winter after all blackberry fruits have been harvested for 3 to 4 months and the plants have stopped growing. In addition, the plants need to be pruned 10 days after the fruit harvest is basically completed (approximately in late July), mainly to remove fruiting branches and weak branches with a thickness of less than 2 mm. In August and September after pruning, integrated fertilizer and water drip irrigation technology should be used, and fertilization should be applied once every two weeks. The nutrient solution mainly uses a water-soluble fertilizer with an N:P:K ratio of 1:1:1 to a concentration of 1‰. 1000 ml of nutrient solution is applied to each plant each time to promote the growth of new branches. The EC value of the nutrient solution is controlled between 1.0 and 2.0, and the pH value is around 5.5 to promote the sprouting of side branches.

[0007] More specifically, from March to June of the year following pruning, integrated fertilization and water drip irrigation should be used, with fertilization applied once a week, with 1000ml of nutrient solution applied per plant each time. From March to April, the nutrient solution primarily uses a high-nitrogen water-soluble fertilizer with a N:P:K ratio of 2:1:1, at a concentration of 2‰; from May to June, the nutrient solution primarily uses a high-potassium water-soluble fertilizer with a N:P:K ratio of 1:1:2, at a concentration of 1‰. This water-soluble fertilizer also contains the following trace and secondary elements in the following mass percentages: 0.8‰ Fe, 0.25‰ Mn, 0.1‰ B, 0.15‰ Zn, 0.1‰ Cu, 0.05‰ Mo, 0.8% Ca, and 0.25% Mg.

[0008] Compared with the prior art, the present invention has the following advantages: 1. The present invention studies various steps of open-field cultivation to develop a set of cultivation methods that are most suitable for and promote the fruiting of blackberries, thereby achieving maximum economic yield and benefits; 2. The present invention determines the optimal pruning method by screening the thickness, pruning length and number of basal branches, secondary branches and tertiary branches of blackberries in winter, thereby effectively increasing the fruiting number of annual blackberry branches and effectively improving economic benefits. DETAILED DESCRIPTION

[0009] The present invention is described in detail below with reference to specific embodiments.

[0010] The blackberry variety Shuofeng No. 2 was planted in the Zhongzhi Two-Berry Industry Demonstration Garden in Caojiaqiao, Baima Town, Jiangsu Zhongzhi Ecological Plant Science Research Institute Co., Ltd. Example

[0011] Two-year-old field-grown blackberry seedlings of similar size and vigor were selected for pruning experiments. Winter pruning was performed four months after fruit harvest. Among them, control: only prune dead branches, diseased branches and very thin and weak branches, leave 1-2 basal branches, keep 4-5 secondary side branches, the length of secondary side branches is controlled at 100-110 cm, keep 25-30 tertiary side branches, the length of tertiary side branches remains basically unchanged, and the pruning amount is 15%; light pruning: leave 1-2 basal branches, keep 4-5 secondary side branches, the length of secondary side branches is controlled at 85-100 cm, keep 20-25 tertiary side branches, the length of tertiary side branches is controlled at 50-55 cm, and the pruning amount is 30%; moderate pruning: leave 1-2 basal branches, keep 4-5 secondary side branches, the length of secondary side branches is controlled at 70-80 cm, keep 15-20 tertiary side branches, the length of tertiary side branches is controlled at 45-50 cm, and the pruning amount is 50%; heavy pruning: leave 1-2 basal branches, keep 4-5 secondary side branches, the length of secondary side branches is controlled at 60-70 cm, retaining 5-10 tertiary branches, each 25-30 cm in length, and 70% pruning, where pruning is calculated as the percentage of branches before and after pruning. Each treatment consisted of three plants, replicated three times, and fruit yield was surveyed and analyzed during the second year of fruiting.

[0012] 1. Changes in blackberry plant biomass before and after pruning.

[0013] Basal branches serve as the main branches and stems of blackberries, and only one or two main stems were retained during pruning. Under different pruning methods, the length and diameter of basal branches remained unchanged before and after pruning, while the number of branches decreased slightly or remained unchanged, with no significant differences among the treatments.

[0014] Secondary lateral branches remained at 4-5 branches under all pruning methods, with the amount of pruning varying from 32.7% to 36.39%. Branch lengths after pruning differed significantly between treatments, with the heavily pruned secondary lateral branches reaching 58.37% of the control.

[0015] The number of branches of the tertiary lateral branches was significantly different under different pruning methods. After moderate pruning, the number of branches was only 49.58% of that before pruning, and after severe pruning, the number of branches was only 26.43% of that before pruning. The branch length was only 33.50 cm, which was 47.76% less than the control.

[0016] 2. Effects of different pruning amounts on blackberry bunches and fruit set.

[0017] Different amounts of pruning significantly affected the length and width of blackberry clusters. Heavy pruning resulted in the longest and widest blackberry clusters, significantly exceeding those in the control and lightly pruned clusters. Cluster length and width increased by 17.73% and 12.76%, respectively, compared to the control. Furthermore, there were no significant differences in cluster length and width between heavy and moderate pruning.

[0018] The number of clusters per blackberry plant varied significantly under different pruning treatments. Moderate pruning produced the most clusters, followed by light pruning, heavy pruning, and the control. Moderate pruning produced the most fruit per cluster and the highest yield per plant. Light pruning, the control, and heavy pruning were the next best treatments, with the number of fruit per cluster and yield per plant increasing by 18.56% and 52.21%, respectively, compared to the control. Heavy pruning produced the heaviest fruit per cluster, followed by moderate pruning, light pruning, and the control. Therefore, moderate pruning resulted in the highest blackberry yield and higher fruit weight.

Claims

1. A pruning method for promoting blackberry fruiting under open-field high-efficiency cultivation conditions, characterized in that: The pruning method is to perform the following pruning management and corresponding water and fertilizer management on blackberries grown in the open field in winter after the fruits are harvested: (1) Basal branch pruning: For the basal branches of blackberries, select 1 to 2 branches with a thickness of more than 20 mm and retain them as the main trunk. The rest of the basal branches are directly pruned and removed. (2) Pruning of secondary side branches: retain 4 to 5 secondary side branches on the basal branches with a diameter of more than 10 mm and a length of more than 80 cm, and remove all other secondary branches. At the same time, prune the retained secondary side branches to a length of 70 cm to 80 cm. (3) Pruning of tertiary branches: retain 15 to 20 tertiary branches with a thickness of more than 7 mm and a length of more than 50 cm on the secondary branches, and prune the tertiary branches moderately, controlling the length between 45 and 50 cm, retaining 3 to 5 axillary buds on each branch, and directly prune away the remaining tertiary branches.

2. The pruning method according to claim 1, characterized in that: The pruning method is performed in winter 3 to 4 months after all blackberry fruits are harvested and the plants stop growing.

3. The pruning method according to claim 2, characterized in that: Before winter pruning, summer pruning is required, that is, the plant needs to be pruned 10 days after the fruit harvest is basically over (around late July), mainly to remove fruiting branches and weak branches with a thickness of less than 2 mm.

4. The pruning method according to claim 3, characterized in that: In August and September after summer pruning, integrated fertilizer and water drip irrigation technology should be used, and fertilizer should be applied once every two weeks. The nutrient solution should mainly use water-soluble fertilizer with N:P:K=1:1:1 to prepare a concentration of 1‰. 1000ml of nutrient solution should be applied to each plant each time to promote the growth of new branches. The EC value of the nutrient solution should be controlled between 1.0 and 2.0, and the pH value should be around 5.5 to promote the sprouting of side branches.

5. The pruning method according to claim 4, characterized in that: From March to June of the second year after winter pruning, integrated fertilizer and water drip irrigation technology should be used, with fertilization once a week and 1000ml of nutrient solution applied to each plant each time.

6. The pruning method according to claim 5, wherein: In March and April of the second year, the nutrient solution primarily consisted of a high-nitrogen water-soluble fertilizer with a N:P:K ratio of 2:1:1, at a concentration of 2‰. In May and June, the nutrient solution primarily consisted of a high-potassium water-soluble fertilizer with a N:P:K ratio of 1:1:2, at a concentration of 1‰. This water-soluble fertilizer also contained the following trace and secondary elements in the following mass percentages: 0.8‰ Fe, 0.25‰ Mn, 0.1‰ B, 0.15‰ Zn, 0.1‰ Cu, 0.05‰ Mo, 0.8% Ca, and 0.25% Mg.