The busy harvesting period at our Yunnan farms was over by early June this year. 

In order to maintain a stable and high yield of blueberries for the next harvest season, it is very important to calculate the timing of post-harvest pruning and implementation of farm management methods. Sufficient pruning management can increase fruit yield and quality, promote the growth of new branches, enhance tree vigor, and reduce pests and diseases.

We have consulted a few experienced colleagues of ours regarding this topic, and summarised some post-harvest management tips for blueberry cultivation in Yunnan.

Blueberry pruning strategy

Pruning is one of the most important and most important agricultural operations, because it has a major impact on yield, ripening time, fruit size and quality. Effective pruning to establish a reasonable plant structure will have a significant impact on the appearance of the fruit, thereby affecting the harvesting speed and cost.

So where do we start when pruning blueberries? 

As the saying goes, "Workers must first sharpen their tools if they want to do well."

Before pruning we must perform the following necessary steps:

– Fully disinfect the tools and clean the trimming tools to avoid spreading various diseases;

– Keep the pruning pliers sharp for easy, effective and less destructive pruning;

In order to increase the pruning speed and reduce the risk of workers being injured by operating the pruning pliers many times for a long time, you can also consider using electric pruning pliers.

Note: After preparing the tools, we enter the actual pruning process. Our professional planting technicians will assess each and every plant onsite, and based on three aspects of "plant height", "tree maintenance", and "branches selection", and select those that do not meet the conditions in order to establish and thereafter maintain a strong plant structure.

I. Control plant height

According to the blueberry plant's age, variety characteristics, growth status, harvesting and spraying requirements and other factors to determine the height of the plant pruning, according to the natural development speed of the blueberry tree, the size of a one-year tree will be smaller than a two-year or three-year-old plant.

II. Keep the plants "happy"

The shape of a "happy" blueberry plant is such that we have to keep the tree shape empty and dense, so that the branches are scattered in layers. A reasonable tree structure can balance the nutrient supply of seedlings and ensure the most effective photosynthesis.

III. Conditions for the retention of branches

Under the main prerequisites of controlling plant height and maintaining tree shape, the branch thickness, the degree of lignification of the branches, the retention of branching branches, and the control of a certain number of cuts are the criteria to determine the reserved branches and cut positions.

Pest control before and after blueberry pruning

Blueberry seedlings that have just been pruned in summer are very vulnerable to pests and diseases due to the wounds from pruning. In order to ensure the health of the plants, special attention should be paid to the prevention and control of pests and diseases before and after pruning. 

I. Thrips

After the blueberry plants are pruned in summer, new branches and leaves will grow. Thrips are prone to break out at this stage. The young blueberry branches and leaves will risk being damaged by thrips and the leaves will turn out to looked twisted and hardened. Therefore, we begin pruning, pesticides can be sprayed inside and outside of the tunnels in advance to reduce the number of thrips in the overall environment as much as possible.

After the blueberry plants are pruned, the number of thrips must be continuously observed. Even if a small amount of thrips are found, pesticides must be sprayed as soon as possible to prevent the thrips from multiplying and thereafter affecting plant growth.

翻译结果

II. Blight 

After the blueberry plants are pruned, the wounds are thereby exposed and can easily be infected with pathogens. Symptoms of branch blight can be seen from fan-shaped dark brown spots on the surface of the cutting mouth. In the summer when the weather is rainy and humid, the risk of branch blight increases. 

Therefore, when blueberry plants are pruned, it is necessary to prevent and effectively control the occurrence of branch blight in advance.

Irrigation and fertiliser management before and after blueberry pruning

The growth of blueberries grown in substrate will be different before and after pruning, therefore the ratio of water and fertilizer and management methods should also be adjusted accordingly.

I. Farm maintenance after blueberry pruning

In the final step of the pruning process, we also need to pay attention to timely cleaning up the dead branches and leaves in the garden, as well as the pest host weeds, etc., to keep the farm environment clean and tidy to prevent plant diseases and insect pests.

Post-harvest pruning is an important measure for blueberry seedlings to expand the crown, rejuvenate old trees, and maintain stable yield and increase yield. But pruning alone is far from enough, and good pest management and water and fertilizer management must be combined to achieve the goal of strong plants, stable and high yield.

Nevertheless, pruning methods vary amongst different varieties, different production areas and different cultivation measures. Thus, it is on ongoing process that farm managers are required to develop their own farm management strategies by learning and experimenting on the different methods according to the characteristics of their own blueberry garden.

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