Key Technical Points for Greenhouse Cultivation and Management of Dragon Fruit
Dragon fruit is also known as red dragon fruit, green dragon fruit, fairy honey fruit, etc. Currently cultivated varieties mainly include white dragon fruit, red dragon fruit, and yellow dragon fruit. Dragon fruit is very rich in nutrients, mainly containing vitamins, cellulose, glucose, carotene, fat, amino acids, and minerals needed by the human body such as phosphorus and iron. It has detoxifying...
Dragon fruit is also known as red dragon fruit, green dragon fruit, fairy honey fruit, etc. Currently cultivated varieties mainly include white dragon fruit, red dragon fruit, and yellow dragon fruit. Dragon fruit is very rich in nutrients, mainly containing vitamins, cellulose, glucose, carotene, fat, amino acids, and minerals needed by the human body such as phosphorus and iron. It has effects such as detoxification, nourishing the stomach and intestines, purifying the blood, lowering blood pressure, lowering cholesterol, preventing vascular sclerosis, constipation, anemia, angular cheilitis, and colds. It also has beauty, skin-nourishing, and anti-aging effects. Dragon fruit is not only a treasure among fruits, but due to its large, pure white flowers and bright red fruit, it is also a rare top-grade ornamental flower. Its key greenhouse cultivation technical points are as follows.
(1) Construction of the greenhouse
The greenhouse can use the "Langfang Type 40 Solar Greenhouse," which features high light transmittance, strong insulation, and low construction cost.
This greenhouse covers 80 m east-west and 18 m north-south, with the greenhouse facing south and biased 5-100 degrees west, which is favorable for light collection. The back wall of the greenhouse is 2.8 m high, with a bottom width of 4.5 m, a top width of 2 m, and a base of 0.7 m. The highest point of the east and west gable walls is 3.5 m, the wall thickness is 2-3 m, and the span inside the greenhouse is 7.25 m. The greenhouse wall construction can be done by mechanical operation. For every 40-50 cm of soil padded, roll 6-8 times, for about 4-5 layers of padded soil, and then carry out manual trimming so that the inner wall is flat and straight, the outer wall slope is gentle, and it is solid and firm. Place 1 iron arch beam every 1.5 m. The arch beam is mainly supported by the central pillar and the front and rear fixed stakes. The rear roof projection is 0.8 m, and the inclination angle is 45 degrees. Dig 1.2 m deep anchor trenches on the east and west sides of the greenhouse, with 23 anchors on each side. Use No. 8 galvanized iron wire in 23 runs on the front and rear slopes to form piano-string-style tension lines, of which 16 runs are on the front slope and 7 runs on the rear slope. Lay 30 cm thick corn stalks on the rear slope, and cover the corn stalks with 30 cm of soil. On the piano-string-style tension lines of the front slope, fix 7 m bamboo poles as arch rods, then cover with polyvinyl chloride drip-free film, and then press tightly with film-pressing wire. In early winter, cover with 4 cm thick straw mats, with a coverage rate of 150%. In January-February, add 4 layers of kraft paper, with a coverage rate of 110%. On snowy days, add 1 layer of old film over the straw mats to prevent the straw mats from becoming too wet and affecting insulation.
(2) Planting of seedlings
Dragon fruit is a vine-like cactus family plant. During artificial cultivation, trellises must be set up for it to climb and grow. First, in the greenhouse, bury 305 cement posts 1.3 m high at a plant spacing of 1.2 m and a row spacing of 1.5 m, and plant 2 dragon fruit seedlings at each cement post. Before planting, apply 12 cubic meters of coarse fertilizer and 50 kg of diammonium phosphate per greenhouse as base fertilizer. After planting, water thoroughly with planting water.
(3) Cultivation management
① Watering. Dragon fruit is a drought-tolerant plant. Generally, normal growth can be achieved when the relative soil moisture content reaches 70%-80%, but its waterlogging tolerance is poor. If water accumulates around 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 the soil is not dry, and watering thoroughly when watering. In addition, during the growth process, do not water before the fruit has set. Wait until the fruit grows to the size of an egg before watering. Under normal circumstances, watering once every 15-20 days is appropriate.
② Fertilizing. Because dragon fruit grows vigorously and bears fruit year-round, it requires more fertilizer. To ensure fruit quality and yield, the principle of mainly using organic fertilizer supplemented by chemical fertilizer must be adhered to when fertilizing.
Under the condition of applying sufficient base fertilizer, after entering the fruiting period, topdress once every 15-20 days, 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, including ring-shaped topdressing, radial topdressing, irrigation-type topdressing, and foliar topdressing. The root system of dragon fruit differs from that of other fruit trees. It does not have a strong taproot but has a fibrous root system, and the root system is very shallow, basically distributed in the surface layer of the soil. Therefore, when topdressing, special attention should be paid not to damage the root system.
③ Pruning. After dragon fruit seedlings are planted, they can sprout and grow rapidly in about 15-20 days. During the growth process, many buds will multiply, forming disordered lateral branches. If not pruned in time, it will affect the normal growth of the plant. When pruning dragon fruit, keep only 1 main stem and cut off all other lateral branches to ensure the normal growth of the main stem. When the main stem reaches 1.3-1.5 m high (when cultivated as a potted flower, the main stem height should be about 1 m), top it to force it to produce lateral branches. These lateral branches are the fruiting branches. According to the plant's growth condition and environmental conditions, about 20 fruiting branches can be kept per plant, and it is appropriate to keep 3 fruits per fruiting branch. If the fruit-setting distance is less than 15 cm, 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.
(4) 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 pest density is high, poisoned 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 rotting. The control method is to hang fly sticky paper on the branches and trunks to trap and kill adult flies, or use the biological pesticide "Qianchongke" 800-fold solution for spraying, which also has a relatively ideal effect.
(5) Harvesting and storage
Dragon fruit generally takes 30-40 days from flowering to maturity. When the fruit skin turns red and has gloss, it can be harvested.
When harvesting, use fruit scissors to cut off the fruit stalk close to the branch. It is best to retain a section of the fruit stalk to reduce nutrient consumption of the fruit during storage and transportation. After harvesting, place it gently in fruit baskets to minimize mechanical damage.
Dragon fruit is storage-tolerant. Generally, after harvesting, it can be stored at room temperature for more than 15 days. If stored in a fresh-keeping warehouse at 10-15 degrees Celsius, the time can be extended to more than 2 months.