Dragon Fruit Training, Pruning, Irrigation and Drainage Methods

Dragon fruit is a relatively common and frequently eaten fruit in our daily lives. It is a tropical fruit, generally grown abundantly in places like Hainan, so if you want to eat delicious and inexpensive dragon fruit, you have to go to Hainan. Although we see dragon fruit quite often, very few people may know much about how dragon fruit grows.

Training and Pruning Techniques

1. Pruning during the seedling stage. After the plant has survived transplanting, it climbs and grows along the concrete post. At this time, side branches sprout during seedling growth. One strong upward branch should be retained, and the remaining side branches should be cut off promptly, which helps concentrate nutrients to supply the strong branch so it can climb upward quickly.

2. When the plant grows to 1.5 m tall, it can be allowed to produce more than 3 naturally drooping branches. After the branches mature and during the period from April to November, these drooping branches have the opportunity to flower and bear fruit. According to observation, the branches in the upper and middle parts, especially the drooping branches, have a higher rate of flowering and fruiting, while the branches in the middle and lower parts rarely flower. From the perspective of branch distribution position, the growth vigor of the upper branches is usually greater than that of the middle and lower branches. This may be due to apical dominance. However, because the upper branches are positioned high and are inconvenient to tie, although their growth vigor is strong, their mechanical tissue strength is poor, and they are often easily broken by wind. The upper branches can gradually be supported, pulled, suspended, and tied, and after the branches mature and begin to flower, they can gradually be made to droop to reduce wind damage.

3. After fruiting, 2/3 of the branches of each plant can be arranged as fruiting branches, and the other 1/3 of the branches can have their flower buds or flowers removed, and their branch growth angle can be narrowed to promote their current vegetative growth and cultivate them into strong reserve fruiting branches. If some plants bear more fruit, the possibility of forming a large number of concentrated flowering branches the next year is relatively small. After a large number of strong branches have formed at the base of the plant, thinning can be used to remove the weak and retain the strong, or weaker branches can be cut back to promote their development into strong vegetative branches. When thinning or cutting back, the overall nutritional area of the plant should be considered. The branches that are thinned out or cut back can be used for: 1) as propagation scions; 2) old branches, after peeling and removing the pith, can be dipped in mustard sauce or used in salads; 3) the flesh of old branches and young branches can become fine dishes, such as fried, cold dressed, or braised; 4) can be used to treat constipation, and has no side effects.

Irrigation and Drainage Techniques

Water is the lifeblood of plant growth and an indispensable component of all organ activities. In the life activities of fruit trees, water plays the role of maintaining cell turgor pressure, ensuring stomatal opening, and allowing carbon dioxide to enter. All chemical changes in the body can only proceed under conditions with water. Nutrients in the soil can only be absorbed and utilized when dissolved in water. More importantly, water is a necessary raw material for photosynthesis and the foundation for forming yield. In addition, only under conditions with water can fruit tree transpiration be maintained, tree body temperature be regulated, and the transport of photosynthetic products and mineral nutrients be ensured. Therefore, in fruit tree cultivation, timely watering is an important measure to ensure early production, high yield, and high quality.

Irrigation should be carried out before fruit trees are affected by water shortage. It must never be done only when the fruit trees already show drought symptoms (such as wilting or fruit shrinkage). Judging whether watering is needed mainly depends on soil moisture. Generally, 60% to 80% of the soil's maximum water-holding capacity is most suitable for the growth and development of fruit trees. Dragon fruit has long grown in desert regions and has a relatively strong tolerance for water shortage. Abroad, measuring instruments are generally used to determine soil moisture to guide irrigation. Determining the irrigation period depends not only on soil moisture but also on climatic conditions and the growth and development stage of the fruit tree itself. In production, watering is mostly carried out during the following periods.

1) From before and after bud break to the flowering period. If there is sufficient water in the soil at this time, it can strengthen the growth of new shoots, increase leaf area, enhance photosynthesis, and allow flowering and fruit setting to proceed normally, laying the foundation for a high yield that year. In spring drought areas, this irrigation is especially important.

2) The period of new shoot growth and young fruit enlargement. This period is often called the critical period of water demand for fruit trees. At this time, the physiological functions of the fruit tree are most active. If water is insufficient, the leaves take water from the young fruit, causing the young fruit to shrink and drop.

3) The period of rapid fruit enlargement. This watering can meet the fruit's requirements for fertilizer and water during enlargement. However, the amount of water applied must be well controlled.

4) Before and after fruit harvest and during the dormant period. In arid areas in autumn and winter, irrigation at this time can store sufficient water in the soil, help decompose fertilizer, and thereby promote the growth and development of fruit trees the following spring. After the last batch of dragon fruit is harvested in autumn and winter, the plant enters the dormant period. If there is appropriate irrigation at this time, it can promote plant growth and encourage branches to become fruiting branches as soon as possible.

Irrigation Methods for Dragon Fruit

1) Flood irrigation

In areas with abundant water sources and flat terrain, whole-orchard irrigation is often practiced. However, this method causes certain damage to soil structure, is labor-intensive and time-consuming, and is not economical. It is now gradually being used less.

2) Border irrigation

Build a tree basin for each plant, or make long borders along the tree rows. During irrigation, lead water into the tree basins or borders. This method saves water and is easy to manage, so it is widely used. However, it likewise damages the soil structure of the tree borders and causes the death of absorbing roots.

3) Hole irrigation

When water sources are lacking, 8-12 holes with a diameter of about 30 cm can be opened outside the outer edge of the tree canopy drip line. The depth of the holes should be such that roots are not damaged. Pour water into the holes, and after the water seeps in, fill them level.

4) Furrow irrigation

Between 2 rows of trees, open irrigation furrows at regular intervals, with a furrow depth of 20-30 cm and a width of about 50 cm. Generally, 2 furrows are opened per row; in dwarf dense-planting orchards, opening one furrow is also acceptable. Lead water into the furrows so it gradually seeps into the soil. This method both saves water and causes less damage to soil structure, and should be advocated.

5) Drip irrigation

Drip irrigation is an advanced irrigation technique developed in recent years through mechanization and automation. It is a watering method that slowly applies water droplets or small water streams to the plant root zone. It is now gradually being adopted in production. Drip irrigation has many advantages: for example, it wets only the soil layer near the crop roots and the surface soil, greatly reducing water evaporation; this system can be fully automated, reducing labor to a minimum; and it can frequently supply water to the root-zone soil, evenly maintaining soil moisture so that it is neither excessively wet nor excessively dry, while also keeping the root-zone soil well aerated. If drip irrigation is combined with fertilization, it can even more continuously supply nutrients to the root system, which is most beneficial to the growth and development of fruit trees and serves two purposes at once. According to foreign data reports, drip irrigation can increase fruit tree yield by 20% to 50%. However, a drip irrigation system requires more piping materials, a relatively large investment, a water tower with a certain pressure and a filtration system, as well as main and branch pipes leading water into the orchard, and capillary tubes and emitters surrounding the trees. In addition, pipes and emitters are easily clogged, strictly requiring good filtration equipment.

Irrigation Amount for Dragon Fruit

No matter which irrigation method is used, the amount of water applied at one time must not be too large or too small. It is suitable to wet through the soil layer where the main root system is distributed. Determining the specific irrigation amount also requires considering soil texture, the growth and development stage of the fruit tree, fertilization conditions, and meteorological conditions. For theoretical calculation of irrigation amount, determining it by soil moisture is the most commonly used. It is generally believed that the minimum irrigation amount is when soil moisture is 60% of the soil's maximum water-holding capacity, while the ideal amount is 80% of the maximum water-holding capacity. In addition, based on the long-term accumulated experience of fruit growers and technicians, when irrigation is considered to have penetrated through, that is actually the most suitable irrigation amount.

The roots of dragon fruit are most afraid of lack of oxygen and taboo water accumulation. If there is too much soil moisture, aeration performance weakens, which hinders root respiration. In severe cases, it can suffocate the active parts to death, causing fruit drop, reducing fruit flavor, and even causing plant death. Therefore, in addition to doing a good job of water conservation and timely irrigation, drainage work such as flood control and waterlogging prevention should also be done well, and drainage ditches and flood diversion channels should be built well. In rainy seasons, preparations for flood control and drainage should be made. The number and size of drainage ditches in the orchard should be determined according to the amount of local rainfall, the strength of the soil's water-holding capacity, and the height of the groundwater level. Under normal circumstances, the drainage ditches in a dragon fruit orchard are about 1 m deep.

Precisely because the market demand for dragon fruit is relatively large, and the price of dragon fruit in the market is not cheap either, especially red-fleshed dragon fruit, which costs about 10 yuan to 20 yuan each when bought in a fruit shop, its profit is also very considerable. Therefore, many people now think that growing dragon fruit is a planting project with very good development prospects!