What are the greenhouse cultivation methods for dragon fruit?
1. Greenhouse construction. The greenhouse can use the "Langfang Type 40 solar greenhouse", which has the characteristics of high light transmittance, strong heat preservation, and low construction cost. The greenhouse covers 80m east-west and 18m north-south. The greenhouse facing south by west 5°-100° is favorable for lighting. The back wall of the greenhouse is 2.8m high, with a bottom width of 4.5m,...
I. Greenhouse construction
The greenhouse can use the "Langfang Type 40 solar greenhouse", which has the characteristics of high light transmittance, strong heat preservation, and low construction cost.
The greenhouse covers 80m east-west and 18m north-south. The greenhouse facing south by west 5°-100° is favorable for lighting. The back wall of the greenhouse is 2.8m high, the bottom width is 4.5m, the top width is 2m, the lower base is 0.7m, the highest point of the east and west gable walls is 3.5m, the wall thickness is 2-3m, and the span inside the greenhouse is 7.25m. The greenhouse wall construction can be done by mechanical operation. For every 40-50cm of soil filled, roll 6-8 times, about 4-5 layers of soil, then carry out manual trimming, so that the inner wall is straight, the outer wall slope is gentle, and it is solid and firm. Place 1 iron arch beam every 1.5m. The arch beam is mainly supported by the central pillar and the front and rear fixed stakes. The rear roof projection is 0.8m, and the inclination angle is 45°. Dig 1.2m deep anchor trenches on the east and west sides of the greenhouse, with 23 anchors on each side. Use 23 strands of No. 8 galvanized iron wire for the front and rear slopes to form a zither-string type tension line, of which 16 strands are on the front slope and 7 strands are on the rear slope. Lay 30cm thick corn stalks on the rear slope, and cover the corn stalks with 30cm of soil. On the zither-string type tension line of the front slope, fix 7m bamboo poles as arch rods, then cover with polyvinyl chloride drip-free film, and then press tightly with film-pressing lines. In early winter, cover with 4cm thick straw mats, with a coverage rate of 150%. In January and February, add 4 layers of kraft paper, with a coverage rate of 110%. On snowy days, add 1 layer of old film on top of the straw mats to prevent the straw mats from becoming too wet and affecting heat preservation.
II. Seedling planting
Dragon fruit is a vine-like cactus plant, and during artificial cultivation it must be trellised for climbing growth. First, in the greenhouse, according to a plant spacing of 1.2m and a row spacing of 1.5m, bury 305 cement piles 1.3m high, and plant 2 dragon fruit seedlings at each cement pile. Before planting, apply 12 cubic meters of coarse manure and 50kg of diammonium phosphate per greenhouse as base fertilizer, and after planting, water thoroughly with planting water.
III. Cultivation management
1. Watering
Dragon fruit is a drought-tolerant plant. Generally, when the relative soil moisture content reaches 70%-80%, it can grow normally, but its waterlogging tolerance is poor. If water accumulates at the roots for a long time, it will cause root rot, leading to reduced yield or death. When watering, grasp the principle of not watering if not dry, and watering thoroughly when watering. In addition, during the growth process, do not water before the fruit sets; wait until the fruit grows to the size of an egg and then water. Under normal circumstances, watering once every 15-20d is appropriate.
2. Fertilization
Because dragon fruit grows vigorously and fruits year-round, it requires more fertilizer. In order to ensure fruit quality and yield, fertilization must adhere to the principle of mainly organic fertilizer, supplemented by chemical fertilizer.
Under the condition of applying sufficient base fertilizer, after entering the fruiting period, topdress once every 15-20d, and note that organic fertilizer and chemical fertilizer should be applied alternately. Pay attention to balanced fertilization, ensure complete nutrients, and fully meet the plant's needs for various nutrients. There are many topdressing methods, such as ring topdressing, radial topdressing, irrigation topdressing, and foliar topdressing.
The root system of dragon fruit is different from that of other fruit trees. It does not have a strong main root; it is a fibrous root system, and the root system is very shallow, basically distributed in the surface layer of the soil. Therefore, when topdressing, special care should be taken not to damage the root system.
3. Pruning
After the dragon fruit seedlings are planted, they can sprout and grow rapidly after about 15-20d. During the growth process, many buds will multiply, forming disorderly side branches. If not pruned in time, they will affect the normal growth of the plant.
When pruning dragon fruit, keep only 1 main stem, and cut off all other side branches to ensure the normal growth of the main stem. When the main stem reaches 1.3-1.5m high (when cultivated as a potted flower, the main stem height should be about 1m), top it to force it to produce side branches, and these side branches are the fruiting branches. According to the plant's growth status and environmental conditions, about 20 fruiting branches can be retained per plant. It is appropriate to retain 3 fruits per fruiting branch. If the fruit-setting distance is less than 15cm, one weak fruit can be removed to ensure the normal growth of the other fruits. After entering the full fruiting period, all branches that have already borne fruit should be cut off to reduce nutrient consumption.
IV. Pest and disease control
Dragon fruit is in a wild state in its place of origin and has strong resistance to pests and diseases. After being introduced and cultivated in China, no serious pests or diseases have been found, but snails and slugs often gnaw on its tender branches, affecting the growth of dragon fruit. Generally, spreading lime can be used for control. If the insect population density is high, poisonous bait can also be used for trapping and killing.
When the fruit matures, fruit flies often lay eggs inside the fruit skin, causing fruit cracking and rotten fruit. The control method is to hang flypaper on the branches and trunks to trap and kill adult flies, or use the biological pesticide "Qianchongke" 800-fold solution for spraying, which is also quite effective.
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