The dragon fruit is native to the tropical deserts of the Americas (Mexico, Colombia) and later in Africa and Asia such as Madagascar, Sri Lanka, Vietnam … Recently in Thailand, China and Taiwan have started growing dragon fruit.
Dragon fruits are sweet and sour. In ripe fruits containing over 80% water, Brix 13-15, total sugar content 11-14%, low protein, fat and organic acids content, potassium, magnesium , Phosphorus) and vitamins, especially Vitamin C (8 mg / 100g fruit).
In Vietnam, according to Prof. Vu Cong Hau, a new dragon fruit planted in the middle of last century, mainly in the south. The area of dragon fruit is about 4,000 ha, the most in Binh Thuan (nearly 3,000 ha) followed by Long An, Tien Giang, a few in the city. Ho Chi Minh City, Khanh Hoa. More recently in some areas in the north have grown dragon fruit. Since 1990, dragon fruit has become a valuable export fruit that is growing. However, dragon fruit growers are also reluctant because of their low consumption, both domestically and abroad, and their price is unstable and difficult to preserve and process.
The harvest season for dragon fruit in the South lasts from April to October, the most from May to August. Life expectancy is 10-12 years, if the soil is good and carefully fertilized may be longer.
1. BOTANICAL CHARACTERISTICS
Dragon fruit tree belongs to Cactaceae family.
Bean creepers: Blue stems and branches, with 3 edges, side edges with many small lobes forming ripples. The bottom of each lobe has 3-5 small spines. Cross-section of the body found two distinct parts, the outer part is the pile of chlorophyll, the core is hard-cylindrical core, photosynthesis in the desert. Each year from 3-4 branches, the next branch after the first branch of the first branch in layers on the head. During the season, the time between the two branches from 40-50 days. The number of branches per tree increases with age, the average one year old trees have about 30 branches, 2 years old 70 stems, 3 years old 100 stems, 4 years old 130 stems, 5 years old maintain about 150 – 170 branches. The length of branches is 80 – 100 cm.
The roots of dragon fruit contain very little water, which helps to drought tolerant plants. There are two types of roots and biogas roots. Root-root is the main root, which grows from the root of the rootstock that grasps to the soil to absorb plant nutrients. After placing 10-20 days, the roots, number and size of roots increased with age. Roots are mainly distributed in the topsoil from 0 to 30 cm. In the soil and spongy enough watering roots grow deeper.
Biogas is a secondary root that grows along the tree to cling to the tree to help climb the tree. The root roots of the body near the soil will go down to the ground into the main roots.
Dragon fruit is a bisexual, relatively large, with an average length of 25 -35 cm, many leaves and petals stick together into a tube. There are many males with horn and a pistil 18-24 cm in diameter, 5-8 mm in diameter, delicate pistil with multiple branches. The dragon flower is around the branches, fragrant. Self-pollinating is the main. Flowers usually bloom 3-5 days from blooming flowers to fruit ripening 30-35 days.
Fruit of the dragon fruit is berry, oval with green leaf ears (by the remaining flower blade), the head of the fruit deep into a cavity. When young, the fruit is green, when ripe it turns red. The fruit is mostly white, a few are yellow or red. The shell can be easily removed from the intestines. In the gut of fruit there are many small black seeds like sesame seeds when not eat seeds. Long fruit size is from 12.5-16.0 cm, diameter 10-13 cm, weight from 300-500 g. To achieve the standard export fruit must be uniform, not large or too small, the fruit must be hard blue, shells ball, beautiful red, no insect bites, especially not cracked shell, no residual quantity of pesticides.
2. ECOLOGICAL REQUIREMENTS
Dragon fruit is native to the tropical dry zone, so it is hot and has good drought tolerance. The most suitable temperature range is from 21 to 29 ° C, not exceeding 40 ° c. Especially dragon fruit is very cold, not resistant to high humidity and heavy rain. Suitable for growing in areas with moderate rainfall and with distinct dry seasons. Dragon fruit is strong light intensity, if the sun is shade or the number of hours light little stem is weak and slow to flower.
Dragon fruit is not cocooned, cultivated on many kinds of soil such as gray soil (Binh Thuan), alkaline soil (Ho Chi Minh City), red soil (Dong Nai), meat or sandy soil (Tien Giang , Long An). The main thing is to have a soil layer of 30- 50 cm thick or more, drainage in the rainy season and enough water for irrigation in the dry season. The pH is from 4 to 5.
The Southern Fruit Research Institute surveys some dragon fruit orchards in Cho Gao district (Tien Giang province), where dragon fruit is grown, showing that the soil is 70 cm deep. The major mechanical components are clay P total 0.037%, P easy to 2.5 mg / 100g, K total mean, humus ratio 3-4%, pH = 4.3.
In Binh Thuan province, dragon fruit is also cultivated on many different soil types, including soil washed away, discolored, rice land 1 crop … However, dragon fruit grows well if fertilizers are applied and raised to raise the topsoil and rain water drainage.
The northern provinces of our country do not grow dragon fruit because of the long cold winter, rainy winds and many days with little sun.
3. NUTRITION REQUIREMENTS
As with other fruit trees, dragon fruit should be sufficient and balanced with NPK and trace elements such as Calcium, Magnesium, Zinc, Iron, Fe, Cu.
During the early planting and the period of creating the branches, the dragon fruit needs more nitrogen (N) and phosphorous (P) to help the plant grow roots and stem branches, healthy plants, lush green, early fruit. Lack of nitrogen and unripened tree stems, small and short branches, turns yellowish green. In contrast, if the nitrogen is too long, the branch is long, soft, resistant to insect pests, prolonged growth time should slow flower.
Potassium (K) makes the tree tough, increases resistance to drought, early fruit, large fruit and good quality. To produce the fruit spread, potassium plus phosphorus increased the rate of beans, beans. Lack of potassium weak soft, yellow turning branches, brown streaks, easy to damage pests.
The micro elements are needed for dragon fruit to achieve high productivity, good quality, in organic fertilizers and foliar fertilizers.