Linhai mandarin orange varieties and cultivation techniques

   Why are Linhai tangerines so sweet? Many friends are puzzled by this question. Let me introduce to you the sweetness of Linhai tangerines.

Linhai Mandarin Orange

Linhai, the hometown of seedless tangerines in China.

Citrus is a business card of Linhai. Whenever the autumn breeze brings coolness, friends from the orange town always say enthusiastically: "The oranges are ripe, why not go and have a taste?"

Linhai Mandarin Orange

Since the 1990s, Linhai honey tangerines, mainly produced in Yongquan, have become famous. Linhai honey tangerines are characterized by "uniform shape, bright color, thin skin, tender flesh, rich slag and flavor", "smell fragrant mist when cut open, sweet juice when put into the mouth", and their unique taste has won many awards in various national competitions, and have won the two highest honors of "China Famous Agricultural Products" and "China Well-known Trademark".

Mandarin oranges are the pride of Linhai people. Even the taxis on the streets are dyed orange-red in Linhai’s unique style.

Orange Varieties

At present, the orange varieties planted in Linhai are Gongchuan brand seedless oranges. In addition, Gongchuan brand seeded oranges, local early oranges, Xucheng oranges, and Jiangjunhong oranges are also widely planted.

brand

The most famous brands of Linhai mandarin oranges are: Yanyutou, Yumanyuan, and Wangbulao. Currently, the three major brands have become the first choice for local governments and enterprises and institutions to visit and give gifts. Especially Yanyutou and Yumanyuan are favored by consumers because of their high-grade packaging carton design.

Yanyutou: Linhai's leading agricultural enterprise, the earliest creator of the Yongquan mandarin orange brand, has a strong political color. The special climate, special soil, special environment, and special planting have nurtured China's unique seedless and top-quality oranges. At the 1999 Zhejiang Province Famous, Special, and New Agricultural Products Shanghai Exhibition, the advertisement "Linhai's Wonderful Orange with Peel" caused a sensation throughout Shanghai. It was praised by the news media as "China's Most Expensive Citrus". The owner of this cooperative is basically replaced every two years, because this place is collective land and is contracted out to outsiders. Bidders must have some strength, especially financial strength. The current owner is Shi Shisheng. The cooperative has a planting area of ​​only 50 mu, and it is hard to imagine that it can meet the needs of governments at all levels.

Six-point cultivation technique of mandarin orange

1. Garden site selection and planting.

The planting site should be a flat land with fertile soil and deep soil layer, or a gently sloping land at the bottom of a mountain, free from water, soil and air pollution; terraces should be built for cultivation on hillsides, and the width of the terraces is generally 3-4 meters. When building a garden, it should be planned according to the specific size of the garden, and roads and water conservancy systems should be set up.

The planting time of Yongquan mandarin oranges is generally around March in spring. Virus-free seedlings should be selected for planting, with Citrus aurantium as the rootstock, and large seedlings are recommended for planting. 70-110 plants per mu are suitable; varieties can be selected that are resistant, easy to plant, easy to manage, and high-quality and high-yield, such as Wenzhou mandarin orange early maturing Miyakawa, Ueno Zaosheng, Wenzhou mandarin orange special early maturing Nichinan No. 1, Oita and other varieties.

2. Reasonable shaping and pruning

After planting, we should pay attention to tree management, do a good job of shaping and pruning the orange trees, cultivate low trunks, short crowns, high-quality, high-yield trees, ensure that the trees are ventilated and light-permeable, and produce fruits in three dimensions. Each tree should be equipped with 3-4 main branches, and each main branch should be equipped with 2-3 secondary main branches. The tree height should be controlled within 2 meters. Citrus pruning can be carried out in two periods: spring and the growing season.

Spring pruning: It is carried out before the citrus sprouts. Spring pruning is generally based on large branch pruning. When pruning, first cut off the redundant upright main branches, secondary main branches and overly dense or overlapping branches in the inner part of the crown, then cut off the diseased and insect-infested branches, weak branches, and carry out a small amount of pruning according to the growth and fruiting of the tree body, combined with methods such as retraction, short cutting, and thinning. After pruning, the wounds of large branches should be protected in time, flattened with a sharp knife, and coated with wound protection agent to prevent water accumulation and mildew and promote healing.

Pruning during the growing season: refers to the various pruning treatments during the entire growing period from the emergence of spring shoots to the harvesting of fruits. The method and degree of pruning are determined according to the age, vigor and fruit yield of the tree. It can remove excessive spring shoots or flowering mother branches in the crown, as well as some branches that are not fully grown, branches with serious flower and fruit drop, diseased and insect-infested branches, disturbed branches, and crossed branches, etc., to adjust the ratio of spring shoots to flower buds and young fruits, and promote the balance of nutrition and reproductive growth;

3. Fertilizer and water management

1. Reasonable fertilization

Fertilization of citrus should be based on the different nutrient requirements of the orange tree at different growth stages, as well as the different varieties (lines), tree order, tree vigor, fruit yield, soil fertility and climatic conditions; the selection of fertilizer types should be based on the pollution-free cultivation of citrus and the cultivation of high-quality fruit (high-sugar fruit), and the principle of combining organic and inorganic fertilizers, with organic fertilizer as the main and inorganic fertilizer as the auxiliary, should be adopted to achieve reasonable formula fertilization. Adult fruit-bearing trees should control the amount of nitrogen fertilizer to maintain a moderate tree vigor. Generally, fertilization should be applied 2-3 times a year, and the annual fertilizer application ratio of N, P, and K should be 0.8:0.6:0.8

, adopt the fertilization method of "check the trees in spring, apply fertilizer appropriately in summer, and apply fertilizer again after harvest".

Pre-bud fertilizer (spring fertilizer): Apply before the spring buds sprout (approximately late February to early March). The amount of fertilizer applied should be determined according to the growth of the tree. The type of fertilizer is mainly nitrogen, supplemented with potassium and phosphorus fertilizers. The amount of fertilizer applied accounts for about 15-25% of the annual amount.

Fruit-strengthening fertilizer: Apply fertilizer after physiological fruit drop and 10-15 days before autumn shoots sprout. For early-maturing varieties and orange trees with many fruits but weak tree vigor, apply fertilizer earlier, to early to mid-June. The main type of fertilizer is potassium, supplemented with nitrogen and phosphorus fertilizers. The amount of fertilizer applied accounts for about 30-40% of the annual amount.

Fruit-harvesting fertilizer: Fruit-harvesting fertilizer accounts for about 35%-45% of the total annual fertilizer application. Early-maturing varieties can be applied after harvest, and mid- and late-maturing varieties can be applied while harvesting; organic fertilizers are the main fertilizers, with a small amount of nitrogen and an appropriate amount of superphosphate or calcium magnesium phosphate fertilizer. In winter, when drought occurs, watering or irrigation should be done before fertilization. For trees with too many fruits, 0.2%-0.3% urea or rare earth micro-fertilizers should be added after harvest and sprayed 1-2 times on the leaves in combination with garden cleaning to promote tree recovery and reduce leaf fall.

2. Use water scientifically: Water has a direct relationship and influence on the growth, flowering, fruiting, fruit quality and flower bud differentiation of citrus. During the spring shoot sprouting and flowering period, fruit expansion period and after harvest, if there is drought, water should be irrigated or watered in time. During the plum rain, typhoon and rainy seasons, the ditches of low-lying citrus orchards in flat areas and seashores should be dredged and drained in time to prevent waterlogging.

In order to produce high-quality citrus fruit with high sugar content, water-controlled cultivation is carried out from late August until the fruit ripens. Water control methods include mulching, high-ridge cultivation, protected land (greenhouse) cultivation, etc., to moderately dry the soil and increase the sugar content of citrus fruit.

4. Flower and Fruit Management

1. Control shoots and preserve fruits: During the period from flowering to young fruit development, for orange trees with few flowers and many spring shoots, remove all or most of the spring shoot nutrient branches in the middle and upper parts of the crown, and pinch off the remaining spring shoots with 3-5 leaves;

When the summer shoots are growing in June and July, leave 1-2 buds at the base of the shoots, and continue to pinch the tops after 2 leaves to control vegetative growth. For trees with many flowers or weak trees, remove the flower branches appropriately during the bud stage to maintain a moderate tree vigor. After the physiological fruit drop period, remove some fruits with deformed growth, obvious diseases and insect pests, too small or poor development to reduce the contradiction between shoots and fruits and improve the fruit setting rate and quality.

2. Foliar fertilization or plant growth regulators to preserve fruit:

Starting from the bud stage, spray 0.3%-0.5% urea or 0.3% potassium dihydrogen phosphate and other foliar fertilizers 2-3 times every 10-15 days (add trace elements depending on the nutrient deficiency in the soil) to meet the nutrients required for fruit development and play a role in protecting flowers and fruits.

3. Reasonable fruit thinning:

The time for fruit thinning is after the first physiological fruit drop, that is, when the citrus fruits are clearly of different sizes, first remove the small fruits, diseased and insect-infested fruits, deformed fruits, and dense and weak fruits; the second fruit thinning is after the fruits are set, around late July to August. The leaf-fruit ratio for early-maturing Wenzhou mandarins is 25-30:1, and the leaf-fruit ratio for mid- and late-maturing Wenzhou mandarins is 20-25:1. The leaf-fruit ratio for weak leaves should be increased appropriately.

5. Optimized pest and disease control

Common major diseases and pests include red spider mites, scale insects, whiteflies, aphids, longhorn beetles, scab, black spot disease and yellow dragon disease.

Prevention and control should start from the orange orchard ecosystem, be based on health cultivation, and adhere to the principle of "prevention first, comprehensive prevention and control". In the main seasons when pests and diseases occur, check the insect situation in the field and focus on strengthening the prevention and control of pests and diseases that affect the appearance of the fruit.

As control agents, high-efficiency, low-toxicity and low-residue pesticides or biological pesticides should be selected. The method of "grasping the two ends and focusing on the middle" should be adopted. In the spring and after the harvest every year, lime sulfur mixture, pine alkali mixture, engine oil emulsion and other agents should be used to clean the orchard in time, and the dead branches and leaves in the orange orchard should be removed and burned in a centralized manner. May and June are the periods when various diseases and insects such as black spot disease, scab disease, scale insects, and red spider mites are prevalent. In particular, citrus black spot disease and scab disease have a particularly obvious impact on the surface of citrus fruit. From the beginning of the plum season to the end of the plum season, imported mancozeb, such as Mengshasheng and Dasheng, can be used. Depending on the occurrence of diseases and insects, insecticides and miticides can be added for comprehensive control.

Spray lime sulfur mixture 1-2 times during the fruit color change period to improve the quality of the fruit and reduce damage from pests and diseases and peeling of the fruit.

6. Harvest and post-harvest commercialization

1. Harvest at the right time: To ensure the quality of citrus fruits on the market and realize post-production value-added, the harvest period should be based on the different sales methods of citrus fruits. The same tree can be selected and picked in batches, first picking the outer fruits on the crown, and then picking the inner fruits of the crown. The harvest time of early-maturing Miyakawa Wenzhou mandarin oranges cultivated in facilities can be postponed to January or February of the following year.

2. Post-harvest commercial processing: After the citrus is harvested, attention should be paid to quality, brand management, and the added value of the fruit should be increased. The harvested citrus fruits should be selected, cleaned, graded, and packaged; unqualified fruits should be removed first, then graded, and the graded fruits should be labeled and then packed. The packaging and external labels should be implemented in accordance with the national citrus standards, and the trademark, variety, grade, packing weight, place of origin, product standard number should be indicated. The place of production and producer should also be marked with barcodes, etc. The packaging boxes and icon marks should comply with the requirements of the national citrus packaging standards.