Detailed Explanation of Propagation Techniques and Pest and Disease Control Measures for Red-Flowered Camellia Oleifera
Red-flowered camellia oleifera is one of the main populations of oil tea cultivated in China, with high value for food, medicine, ornamental use, and landscaping. Below, let us look at the propagation techniques for red-flowered camellia oleifera.
I. Biological Characteristics of Red-Flowered Camellia Oleifera
Evergreen shrub or small tree, tree height can reach 7 m. Bark grayish-white, smooth; leaves oblong, smooth and hairless on both sides, with sparse short serrations along the margins; flowers bloom from late winter to spring, red or pink, solitary flowers terminal or axillary, petals 6-8, obcordate. Capsule spherical, hairless, pericarp woody, diameter 4-6 cm, single fruit weight 26-160 g.
II. Suitable Growing Conditions for Red-Flowered Camellia Oleifera
Red-flowered camellia oleifera prefers a warm and humid environment. In Hubei Province, the suitable range is low mountain hills at an altitude of 500-1 000 m, with an annual average temperature of 14-17 degreesC, precipitation >=1 000 mm, relative humidity 70%-80%, frost-free period 220-270 d. The soil is best as loose, fertile, moist, well-drained acidic soil such as mountain yellow soil, yellow-brown soil, sandy loam, and red soil, with a soil layer thickness of more than 60 cm, pH value 5-6.5, slope aspect as sunny slope and semi-sunny slope, and slope below 25 degrees.
III. High-Yield Cultivation Techniques for Red-Flowered Camellia Oleifera
3.1 Variety Selection
Priority is given to selecting superior clones and superior individual plants bred by the Subtropical Forestry Research Institute of the Chinese Academy of Forestry as seed sources. Their main economic and technical indicators are: average fresh seed yield rate 22.0%; kernel oil content 65%, with an average of 3 kg oil per 100 kg fresh fruit; average oil yield at full fruiting stage 15 kg/hm2.
3.2 Seedling Raising Techniques for Red-Flowered Camellia Oleifera
Seedling raising of red-flowered camellia oleifera is divided into: sowing seedling raising, cutting seedling raising, and grafting seedling raising. In production, grafting seedling raising is primary, mostly using light substrate bud seedling rootstock grafting.
3.3 Afforestation Techniques for Red-Flowered Camellia Oleifera
(1) Selection of afforestation site: The afforestation site should preferably be selected in hilly and mound areas at an altitude of 500-1 000 m, requiring sufficient sunlight, a slope below 25 degrees, deep soil layers, loose texture, and slightly acidic plots (pH value 5-6.5). Steep mountain slopes, shady slopes, and low-lying waterlogged land must not be selected.
(2) Land preparation: Land preparation time is before October. After land preparation, it is best to sun-dry for one month before digging holes. There are mainly the following three methods of land preparation. 1. Full reclamation land preparation. For low mountains and gentle slopes with a slope of less than 10 degrees, full reclamation land preparation is implemented. Deeply plow the forest land comprehensively to more than 20 cm, then dig holes at fixed points according to the planned row spacing. The planting hole specifications are 60 cm x 60 cm x 60 cm. 2. Strip reclamation land preparation. For forest land with a slope exceeding 10 degrees, terrace-style land preparation is used. For forest land with a slope of 10-15 degrees, the terrace surface width is 3-6 m, and holes are dug on the strips; for forest land with a slope of 15-20 degrees, the terrace surface width is 1.5-2.0 m, and holes are then dug on the strips. The terrace surface width, distance between terraces, and distance between holes are determined according to terrain and planting density. The hole digging specifications are the same as for full reclamation. 3. Hole reclamation land preparation. For plots with less original vegetation, concentrated precipitation, and severe water erosion, wind erosion, and soil erosion, hole reclamation land preparation is adopted. Dig holes at fixed points along contour lines according to plant and row spacing, with the same specifications as full reclamation.
(3) Afforestation density: This is mainly determined according to the biological characteristics of red-flowered camellia oleifera, site conditions, and afforestation purpose, etc. Generally, 80-120 plants are planted per 667 m2.
(4) Base fertilizer: In order to improve soil fertility, promote seedling growth, and achieve high yield as early as possible, after digging holes, appropriately apply 3-5 kg of garbage compost, rice straw, and farmyard manure according to local conditions, add 0.25-0.30 kg of compound fertilizer per hole, then backfill topsoil and fill the hole into a steamed bun shape for use during afforestation.
(5) Seedling selection: The quality grade specifications of red-flowered camellia oleifera seedlings are shown in Table 1. Grade I and Grade II qualified seedlings are required for afforestation, and light substrate bud seedling rootstock grafted seedlings are recommended for afforestation.
Table 1 Quality Grade Specification Indicators for Red-Flowered Camellia Oleifera Seedlings
(5) Seedling planting: The best planting time for cutting seedlings and sowing seedlings is December to January, and no later than mid-March. For container seedlings, afforestation can be done from late October to before the end of May of the following spring, with early March to late April being the best. When planting, ensure roots are spread, seedlings are upright, and soil is firm. Seedlings should not be planted too deeply, with the grafting interface level with the ground being appropriate. After planting, water thoroughly to settle the roots.
3.4 Tending and Management of Red-Flowered Camellia Oleifera
(1) Tending and management of young forests: 1. Replanting. Replant in the spring of the second year after afforestation, using strong seedlings of the same age to fill in diseased and missing plants. 2. Water, soil, and fertilizer management. After afforestation, attention should be paid to drainage during the rainy season, and timely irrigation should be done during summer and autumn droughts. In the first year after afforestation, to protect the root system, weeding must not be done in summer; weeding is done after September. From the second year onward, tending is carried out 1-2 times per year, the first time in May-June and the second time in August-September. The main tasks are loosening soil, weeding, earthing up, and expanding holes. During the young forest period, green manure, medicinal herbs, oil crops, and other crops can be interplanted using gaps between trees. In winter, apply 10-20 kg of farmyard manure per plant; before spring shoots sprout, apply additional nitrogen fertilizer, with a nitrogen, phosphorus, and potassium ratio of 2:1:1 being best. 3. Tree shape cultivation. When seedling height reaches 40-50 cm after planting, pinch off the growing tip to set the trunk.
In the first year, select and retain 3-4 strong-growing, well-positioned lateral branches at 30-40 cm as main branches; in the second year, retain 2-3 strong branches on each main branch as secondary main branches; in the 3rd-4th years, while continuing to cultivate the main and secondary main branches, cultivate the strong spring shoots on them as lateral branch groups, and make the proportions among the three reasonable and evenly distributed, forming a low natural round-headed and open-center crown. Young trees need their flower buds removed in the first 3 years to maintain vegetative growth of the tree body and accelerate crown formation.
(2) Tending and management of mature forests: 1. Reclamation. Winter reclamation is from November to January of the following year, and can be strip reclamation, hole reclamation, and trench reclamation, with a depth of 20-25 cm; summer reclamation is from May to July, with a depth generally of 10-15 cm, requiring shallow hoeing.
2. Pruning. Red-flowered camellia oleifera is not suitable for heavy-intensity pruning. Remove dead branches, diseased and pest-infested branches, water sprouts, and high forked branches, and cultivate a natural open-center tree shape or natural round-headed tree shape.
3. Fertilization. During the full fruiting period of mature red-flowered camellia oleifera forests, in order to meet the needs of vegetative growth of the tree body and large amounts of flowering and fruiting, fertilization should have a reasonable ratio of nitrogen, phosphorus, and potassium, generally N:P:K at 10:6:8. The total amount of quick-acting fertilizer applied per plant each year is 1.5-2.0 kg, and organic fertilizer 15-20 kg. Increasing the application of organic fertilizer can not only effectively improve soil physical and chemical properties, increase soil fertility, increase the number of soil microorganisms, and prolong fertilizer efficiency, but also increase the oil content of the fruit.
(3) Bee pollination: Red-flowered camellia oleifera mainly relies on bees, ants, and other insects for pollination. First, beneficial pollinating insects should be protected; second, bees should be kept around the forest land, which can both increase economic income and meet the pollination needs of red-flowered camellia oleifera, improving the fruit-setting rate.
IV. Main Pests and Diseases and Their Control
The main diseases of red-flowered camellia oleifera are anthracnose and sooty mold, and the main insect pests are camellia geometrid and tea shoot moth. The principle of "prevention is more important than treatment" should be implemented, with cultivation techniques as the foundation and comprehensive control measures combining biological and chemical control. Protect and utilize natural enemies and carry out biological control.
V. Fruit Harvesting
The fruit maturation time of red-flowered camellia oleifera is mid-September. Immature fruits have low yield, low oil extraction rate, and poor quality after harvest, so early picking is strictly prohibited. When the down on the outer pericarp of red-flowered camellia oleifera falls off, the color deepens, the luster becomes brighter, the outer pericarp changes from green-yellow to red or reddish-brown, and the kernel becomes hard, it is mature. When picking, use a small knife or small hook to remove the fruit; strictly prohibit breaking branches or beating the trunk, which damages the tree body and may affect new flower buds and the next year's yield. Do not pick fruit and randomly strike with poles. After the fruit is brought back, it should be dried in the sun promptly for threshing, impurities removed, and after it is fully dried, stored for oil pressing. Seeds used for seedling raising must not be exposed to the sun; store them in sand for later use.
High-Yield Cultivation Techniques for Red-Flowered Camellia Oleifera
Red-flowered camellia oleifera, also known as Yunnan camellia, belongs to the genus Camellia in the family Theaceae. It is one of the main populations of oil tea cultivated in China, and is also a superior camellia variety with relatively high value for food, medicine, ornamental use, and landscaping. Tengchong red-flowered camellia oleifera in Yunnan is a superior population among China's oil tea. According to measurements, the seed oil yield is 25%-30%, and the oil contains 90% unsaturated fatty acids. It has the effects of softening blood vessels, lowering blood lipids, nourishing and refreshing, and expelling parasites and strengthening the stomach; it can also be used as a pure natural high-quality cosmetic raw material. The oil cake left after pressing oil from its seeds can be used as biological insecticidal pesticide and high-quality organic fertilizer; with the gradual improvement of people's living standards, market demand for red-flowered camellia oleifera will continue to increase. Therefore, carrying out protection of Tengchong red-flowered camellia oleifera variety resources, developing red-flowered camellia oleifera planting, and conducting deep processing of red-flowered camellia oleifera have very broad prospects. At present, the main problems in Tengchong red-flowered camellia oleifera production are mixed and degraded varieties, extensive management, indiscriminate picking and excessive harvesting, lagging product processing research and development, and relatively low overall benefits. Technical departments and the broad masses of farmers need to carry out work in local superior variety selection and breeding, promotion of pollution-free high-yield planting techniques, deep processing of red-flowered camellia oleifera products, and expansion of application fields, so that Tengchong red-flowered camellia oleifera can exert stronger industrial advantages and make greater contributions to local economic development. The cultivation techniques for red-flowered camellia oleifera are now introduced as follows:1. Growing Conditions
(1) Temperature. Tengchong red-flowered camellia oleifera grows in high-altitude mountainous areas at 1500-2500 meters, with strong cold resistance. It can flower and fruit normally even at a temperature of minus 10 degreesC. When the temperature exceeds 35 degreesC, growth and development will be affected and growth stops. Red-flowered camellia oleifera is suitable for growing in mountainous and semi-mountainous areas with an annual average temperature of 8-16 degreesC.
(2) Light. Adult red-flowered camellia oleifera prefers an environment with sufficient light, and can only flower and fruit normally with more than 4 hours of light per day; however, during the young stage it avoids sun exposure and needs certain shading conditions.
(3) Soil. Red-flowered camellia oleifera prefers loose, fertile, well-drained slightly acidic soil. It can grow within a pH range of 4.5-7.0, with pH 5.0-6.5 being most suitable. It grows poorly in alkaline soil and places with high groundwater levels.
2. Propagation Techniques
(1) Seed propagation. In autumn, it should be sown as soon as collected. If it cannot be sown in time, it should be stored in moist sand and sown in February of the following year. Select flat terrain, convenient transportation, loose soil, convenient irrigation, and well-drained land as the nursery. Before sowing, disinfect the soil, carefully plow and harrow, apply sufficient base fertilizer, and prepare the seedbed; at the same time, disinfect and germinate the seeds, and sow by drilling. After seedlings emerge, strengthen management promptly.
(2) Cutting propagation. Select branches from plants that grow robustly, have large and full fruits, and high yield as cuttings. Carry out cutting in mid-to-late June or mid-to-late August. The sand bed or seedling bed should be disinfected. Select current-year semi-lignified branches with complete leaves and full axillary buds for cuttings. The cutting length is 6-8 cm, with 1 leaf retained at the top. Treat with rooting powder and insert immediately after cutting; after insertion, press the bed soil firmly, provide shade, and water thoroughly; afterward, spray water on the leaves 2-3 times a day to keep the soil moist. In winter, the shade shed can be converted into a plastic greenhouse to prevent frost damage to the cuttings.
(3) Grafting propagation. Three methods can be used: approach grafting, branch grafting, and bud grafting. Approach grafting is easy to survive and grows quickly, but propagation speed is slow and material utilization rate is low; branch grafting and bud grafting save materials, are convenient to operate, and have fast propagation speed. As long as the operation technique is proficient, temperature and humidity are suitable, and management is fine, the survival rate can reach more than 70%. White-flowered camellia or low-yield, poor-quality red-flowered camellia oleifera can be used as rootstock. Select red-flowered camellia oleifera varieties that grow robustly, have a good tree shape, are more than 15 years old, have large fruits, and high yield as scions, and pay attention to the construction and protection of superior variety scion orchards.
3. Planting Techniques for Red-Flowered Camellia Oleifera
(1) Land preparation. In places with steep slopes, dig terraced planting belts along the horizontal direction of mountain contour lines with a belt spacing of 3 meters and a belt surface width of 1.5 meters. Inside, dig bamboo-joint drainage ditches 20 cm wide and 20 cm deep, and deep-plow the soil 30 cm. Dig square planting holes with a hole spacing of 2 meters and length, width, and depth of 60 cm each, or dig cylindrical planting holes with a diameter of 60 cm. In places with smaller slopes or where intercropping with crops is done, planting holes can be dug directly according to the above requirements. Plant 110 red-flowered camellia oleifera plants per mu. After the forest matures, thinning dense areas and filling sparse areas can be carried out, or plants can be moved elsewhere for planting.
(2) Transplanting
1. Transplanting time. Transplanting must be done in the rainy season, with the 15 days around the Dragon Boat Festival being the best time, and no later than early August; lift seedlings and plant them in time to avoid seedling roots being exposed to wind and sun; where conditions permit, use two-stage nutrient bag seedling transplanting, and the survival rate can reach more than 90%.
2. Planting method. Apply an appropriate amount of compound fertilizer or organic fertilizer as base fertilizer and backfill part of the topsoil. When planting, require proper placement, straightening, backfilling soil, gently lifting, firming by stepping, and watering to settle the roots. After planting, cover with plastic film, with a coverage area of 1 square meter around the seedling being best, and cover the edges tightly with soil.
4. Management of Young Forest Land
(1) Thinning and replanting. In oil tea orchard land after afforestation, if missing plants are found, nutrient bag seedlings of the same variety should be selected for replanting to ensure full and uniform stands.
(2) Cultivation and weeding. Carry out cultivation and weeding once in the year of afforestation, and 2 times per year within 3 years, the first time in June and the second time in September. Chemical herbicides can also be used for weeding, but care must be taken not to spray the liquid on the tender leaves of red-flowered camellia oleifera.
(3) Topdressing. Topdress at least once a year, preferably in winter and spring. Organic fertilizer and inorganic fertilizer should be used together, and nitrogen, phosphorus, and potassium fertilizers should be applied in combination; the amount of topdressing depends on soil fertility and seedling size. There are 3 fertilization methods: broadcasting, ring trench application, and radial trench application.
Broadcasting. Evenly scatter fertilizer around the rhizosphere under the tree crown, and bury it into the soil together with cultivation and weeding.
Ring trench application. Dig circular or semicircular topdressing trenches 20 cm wide and 20 cm deep along the outer edge of the rhizosphere covered by the tree crown. Apply fertilizer into the trenches and then cover with soil.
Radial trench application. Dig radial fertilization trenches around the rhizosphere covered by the tree crown, apply fertilizer into the trenches, and then cover with soil.
(4) Shaping and pruning. Prune in late winter and early spring. In the second year after planting, retain the spring shoot sprouted from the terminal bud so that it quickly forms the trunk; when the trunk height is about 60 cm, select and retain 3-4 strong main branches around the trunk, and on each main branch select and retain 2-3 secondary branches, so that an umbrella-shaped crown is formed.
(5) Intercropping in forest land. Intercropping in forest land can achieve the effect of cultivation replacing tending, achieve the purpose of using short-term crops to support long-term crops and promoting seedling growth. Intercropped crops should be selected that do not compete with oil tea for light, fertilizer, or water, such as peanuts, beans, and amaranth. Tall-stemmed, vine, and water-consuming crops are not suitable for selection.
5. Management of Mature Forest Orchards
(1) Forest clearing. First, remove scattered upper-story tall trees in the oil tea forest; second, remove miscellaneous shrubs between oil tea belts, so that oil tea trees have ventilation and light. Forest clearing should be carried out once every winter.
(2) Pruning. Pruning is best carried out in late autumn and early winter and can be combined with forest clearing. Cut off diseased and pest-infested branches, parasitic trees, water sprouts, dry branches, and aging branches on the oil tea tree body. Pruning should be adapted to the tree, cutting dense growth and retaining sparse growth, removing weak growth and retaining strong growth, heavily pruning weak trees and lightly pruning strong trees.
(3) Loosening soil and fertilizing. Deeply turn the surface soil of the planting belt once a year (preferably without damaging the oil tea fibrous roots), dig out all miscellaneous and shrub root systems, crush the turned soil and spread it flat. The miscellaneous and shrub root systems between terraced planting belts must not be dug out, so as to maintain soil and water. Soil loosening time is in late spring and early summer each year. For fertilization methods, refer to the young forest land management section. Ring trench application and radial trench application are preferable, and broadcasting is not suitable.
(4) Pest and disease control. The diseases of red-flowered camellia oleifera mainly include anthracnose, powdery mildew, soft rot, and sooty mold; the insect pests mainly include scale insects, red spiders, stem-boring moths, tea shoot moths, tea caterpillars, scarab beetles, and sawflies. The principle of “prevention first, comprehensive control” should be implemented. Based on forest health cultivation techniques, biological control methods should be used as much as possible to control the occurrence and spread of pests and diseases. When pesticide control is needed, pollution-free pesticides should be used.
(5) Bee pollination. Red-flowered camellia oleifera mainly relies on bees, ants, and other insects for pollination. First, beneficial pollinating insects should be protected; second, bees should be kept around the forest land, which can both increase economic income and meet the pollination needs of oil tea, improving the fruit-setting rate.
6. Fruit Harvesting
The fruit of Tengchong red-flowered camellia oleifera is a capsule, with a woody outer pericarp, spherical or oblate-spherical. The fruit differs greatly among varieties. The seed shell is horny and dark brown. Seeds are spherical, hemispherical, or polygonal, with a small embryo and oil-rich endosperm. The fruit maturation time of red-flowered camellia oleifera is from mid-November to early December. Immature fruits have low oil yield and poor quality after harvest, so early picking is strictly prohibited. The sign of fruit maturity is that the down on the outer pericarp falls off, the color deepens, and the luster becomes brighter; the seed shell changes from yellow to brown or deep black. The kernel becomes hard, changes from white to yellow-brown, and is glossy. The fruit maturation period of red-flowered camellia oleifera is exactly the bud stage of new flower buds and leaf buds. When harvesting, tools with a small knife or small hook should be used. Breaking branches to pick fruit is strictly prohibited. After the fruit is brought back, it should be promptly sun-dried for threshing, impurities removed, and after it is fully dried, stored for oil pressing.
How to Plant Red-Flowered Camellia Oleifera: A Highly Adaptable Plant of the Theaceae Family
Red-flowered camellia oleifera is a plant of the genus Camellia in the family Theaceae, and is a tree species with ornamental and economic value. It is a woody oil tree species with extremely strong applicability and potential for deep development, and can form a multi-level industrial structure. So, do you know how to plant red-flowered camellia oleifera? Below, based on the growth patterns of oil tea, the editor of wed114 tells everyone some planting tips, hoping to be helpful.
How to Plant Red-Flowered Camellia Oleifera: Selection of Afforestation Site
Red-flowered camellia oleifera is a sun-loving tree species, preferring light, warmth, and humidity, with a developed root system and strong adaptability. Therefore, the afforestation site should be selected on south-facing, east-facing, or southeast-facing forest land at an altitude of 600-1500 m on middle slopes, lower-middle slopes, or gentle slopes (below 25 degrees), with deep soil layers, loose soil texture, and well-drained acidic or slightly acidic (pH 5-6) red soil, yellow-red soil, or yellow soil being preferable.
How to Plant Red-Flowered Camellia Oleifera: Propagation Techniques
Use local common oil tea fruits with strong adaptability and strong resistance to pests and diseases to cultivate rootstock. Select current-year robust, full-axillary-bud, disease-free semi-lignified new shoots as scion sticks, and graft by approach grafting, branch grafting, and bud grafting. It is best to graft as soon as collected. If long-distance transport is needed, the lower end of the scion stick should be wrapped with water-saturated absorbent cotton to keep it moist.
Seed propagation: After the fruit matures in October, harvest it promptly. After shelling, spread it in a cool place or mix it with moist river sand for storage. The seedling nursery should be selected near the afforestation site in a plot with sufficient water, good drainage and irrigation, fertile soil, loose structure, good aeration, and strong fertilizer retention. Before sowing, carry out moist sand germination treatment of seeds. When the seeds break through the shell and germinate, sow at a spacing of (10-15) cm x (3-5) cm. After seedlings emerge, promptly remove weeds and pay attention to shading. Thirty days after bud seedlings emerge, topdress with water-soluble fertilizer mainly composed of compound fertilizer. The principle is frequent and light application, applying 2-3 times per month, with concentration controlled between 0.1% and 0.3%. If shoots emerge too late in November, appropriately spray 0.5% monopotassium phosphate to accelerate terminal bud formation and prevent cold damage.
Planting method: Before planting, appropriately prune the main root to promote lateral root growth. After dipping the roots in yellow mud slurry, according to the principle of “three burials, two tramplings, and one lifting,” make the hole soil fine and broken, plant the seedling stem upright, and plant toward the inner side, planting appropriately deep (with soil covering 5 cm above the root collar as appropriate). Make the root system spread out, fill soil and firm it, cover with loose soil, and be careful to water to settle the roots.
Cutting propagation: Select branches from mother plants that grow robustly, have large and full fruits, and high yield as cuttings. Use current-year lignified spring shoots, cut 4-5 cm, and carry out cutting in May-June, retaining 1 leaf and 1 bud. After treatment with 100 mg/kg NAA and ABT rooting powder, when cutting, open 60 degrees slanted “V” shaped trenches at a row spacing of 10 cm, and insert cuttings at a plant spacing of 5 cm on the prepared nursery land. Place the cuttings in the trenches in sequence, with the leaves and buds of the cuttings exposed above the ground, leaves facing upward, then backfill soil and press firmly. The insertion depth is about 2/3 of the cutting length. After watering sufficiently, set up bamboo arches on the cutting bed, cover with agricultural film, and cover the shed with shade netting, maintaining 70%-80% shading. Keep the temperature inside the shed at around 30 degreesC to facilitate seedling survival.
How to Plant Red-Flowered Camellia Oleifera: Area
Land Preparation and Site Preparation
Land preparation is generally arranged in the autumn and winter of the year before afforestation and completed 1 month before afforestation. According to labor, funds, and afforestation site conditions, choose suitable land preparation methods according to local conditions. On flat land and gentle slope mountainous land with a slope below 15 degrees and slight soil erosion, carry out full land preparation. The reclamation depth is required to be 20-25 cm in mountainous areas and 25-30 cm in hilly areas; in low mountain and hilly areas with a slope of 15-25 degrees, adopt horizontal terrace land preparation (terraced field land preparation) and horizontal trench reclamation land preparation, with a horizontal gradient generally of 2-3 m and a soil turning depth of 30-40 cm; on steep slopes above 25 degrees and in places lacking labor and funds, hole-shaped land preparation and fish-scale pit land preparation can be used, with a hole digging depth of about 50 cm. Oil tea is mostly planted on sloping land. To prevent soil erosion, when clearing forest land, all trees on the mountain top should be retained, part of the vegetation belt should be retained on the mountainside, and miscellaneous shrubs should be retained at the foot of the mountain.
Reasonable Close Planting
Plant in spring on cloudy and rainy days or after rain, with a plant and row spacing of 2.6 m x 2.6 m, and a planting density of 100-120 plants per 667 m2.
Tending and Management of Red-Flowered Camellia Oleifera
Young Forest Management
Thinning and replanting: If missing plants or diseased and dead plants are found, large seedlings or container seedlings of the same variety type should be selected for replanting in a suitable afforestation season, and management should be strengthened so that replanted seedlings and forestland seedlings grow in a balanced way. According to years of practice, for every 6.7 hm2 of contiguous orchard, mixing 3-5 strains results in lower yield. Cultivation and weeding: In May of the afforestation year, earth up and straighten seedlings, covering the grass turf cut down around the tree base surface to earth up the tree base. In September-October, combine fertilization with weeding and soil loosening. Afterward (2-3 years), loosen soil and weed 2 times each year. Where conditions permit, in the first 3 years after afforestation, reasonably intercrop mainly green manure or leguminous plants, implementing cultivation as tending. Afterward, in addition to normal weeding and soil loosening each year, deep turning to improve soil should also be carried out every other year according to soil conditions. Deep turning is generally carried out in autumn and winter and can be combined with post-fruit topdressing. The soil turning depth should be controlled at 30-50 cm, and soil clods should not be broken. Timely topdressing should mainly apply nitrogen fertilizer to promote vegetative growth of young trees. In southern hilly and mountainous areas, ring or radial trench fertilization is mainly used. Ring trench application means digging circular or semicircular trenches 20-30 cm wide and deep along the outer edge of the tree crown and applying fertilizer into them; radial trench application means opening radial trenches along the central axis of the tree crown and applying fertilizer into them. Generally, no fertilizer is applied in the year of planting. Where conditions permit, in June-July after seedlings recover, appropriately water some dilute human and animal urine. Starting from the second year, fertilizer can be applied 2-3 times per year. About half a month before new shoots sprout in March, apply quick-acting nitrogen fertilizer; in May-June, combine weeding and soil loosening, and apply 50-100 g urea per plant; in early November, use soil and miscellaneous manure or manure as winter fertilizer, applying 5-10 kg per plant. As the tree body grows, the fertilization amount increases year by year. Shaping and pruning: After planting oil tea, when it grows to about 1 cm, cut back the trunk at 30-50 cm from the interface to allow new branches to sprout, and from them select and retain 4-5 robust lateral branches in different directions with a vertical spacing of 10-15 cm as main branches; in the second year, retain 2-3 strong branches on each scaffold branch as secondary main branches.
Mature Forest Management
Clearing the stand: Remove miscellaneous shrubs, weeds, and mixed timber forest and economic forest tree species in the oil tea forest, dig out old, residual, diseased, and weak oil tea trees, and improve ventilation and light transmittance of the oil tea forest. Scientific pruning: Prune every year after fruit harvest until sap flow begins the following year. Spring shoots are the main source of fruiting branches and should be retained as much as possible. Mainly cut off water sprouts, ground-foot branches, diseased and pest-infested branches, thin and weak branches, and some branches affecting the light of the whole plant, cultivate an open shape and an oval or semicircular crown with a large light-receiving area, increase the fruiting surface, and improve yield. For overly dense trees, a small number of upright large branches with a diameter of 2-4 cm should be cut off to improve inner-canopy fruiting capacity. For stands with good site conditions, neat forest form, tree age below 30 years, and low yield, superior clones can be used for top grafting to change varieties. Loosening soil and fertilizing: After oil tea enters the full fruiting stage, according to site conditions and variety type, hoe weeds and loosen soil at least 2 times per year, and deep dig once every 3 years. The time for hoeing weeds and loosening soil should differ among regions, generally in late spring or autumn, with depth controlled at 5-10 cm. Deep digging should be carried out after fruit harvest until sap flow begins the following year, with depth controlled at 15-20 cm. According to different site conditions and growth status, scientifically and reasonably use chemical fertilizers, microbial fertilizers, and trace element fertilizers. In on-years, mainly use phosphorus and potassium fertilizers and organic fertilizers; in off-years, mainly use phosphorus and nitrogen fertilizers. Apply more than 15 kg compound fertilizer per 667 m2 each year, with emphasis on organic fertilizer. In summer dry seasons, oil tea bears a large amount of fruit, and this is exactly the period of fruit expansion and oil conversion, which consumes a large amount of water. Attention must be paid to reasonable irrigation. Where conditions permit, build water storage ponds in the tea garden according to terrain, and irrigate through water diversion and pipe network water transmission. Where conditions are poor, dig bamboo-joint trenches 60 cm long, 40 cm deep, and 30 cm wide above the tree body (outside the direct projection of the tree crown) for irrigation, which can achieve obvious results. Bee pollination: In newly opened oil tea forest land, bees must be artificially introduced and released. That is, on the terrace ridge walls of the oil tea forest land or under tree crowns with loose soil, make bee-attracting holes with a diameter of 1.0-1.5 cm and a depth of 30-40 cm. In the evening, place one mated or mating large digger bee in each hole, with 15-20 holes per 667 m2. Or use the flower-inserting small cover method, that is, introduce oil tea ground bees, striped ground bees, etc., with 4-7 covers per 667 m2, and 50-100 bees per cover. After 3-5 years, the pollination needs of oil tea can be met. When keeping Italian bees, poisoning relief must be fed. For every 10 bee combs, 25-50 g of detoxification agent No. 1 or No. 2 can be given. If rotten pupae are found, remove them promptly.
Pest and Disease Control of Red-Flowered Camellia Oleifera
There are many pests and diseases harming oil tea, among which the main ones causing severe yield reduction are anthracnose, soft rot, root rot, sooty mold, tea shoot moth, weevils, and longhorn beetles. The main types of pests and diseases differ among regions and years, and the main targets for control should be determined according to specific conditions. Pest and disease control of oil tea should implement the policy of “prevention first, comprehensive management,” mainly using biological control and forestry technical control. Through measures such as pruning, reclamation, and tending, achieve the effect of strengthening tree vigor and destroying the living environment of pests and diseases. Attention should be paid to protecting natural enemies, reducing sources of pests and diseases, controlling pest and disease damage, and reducing losses. In principle, pesticides are not used, and highly residual toxic pesticides are strictly prohibited. Only when a large-scale outbreak causes disaster and serious damage may chemical agents be used for control.
Fruit Harvesting of Red-Flowered Camellia Oleifera
When the fruit matures, the pericarp is smooth, red with yellow, and the luster becomes brighter. The seed shell is deep black or yellow-brown, glossy, and the kernel is white with yellow, appearing oily and bright. Taining County red-flowered camellia oleifera belongs to the Cold Dew seed series and is generally picked in early October. The maturity of oil tea fruit is affected by factors such as weather, latitude, altitude, forest land environment, soil fertility, and management level. Generally, high temperature and dryness cause early maturity, while low temperature and rain delay maturity; low latitude and low altitude mature early, while higher latitude and high altitude areas mature late; old forests mature first, young forests mature later; barren land matures first, cultivated land matures later; excessive nitrogen fertilizer application makes oil tea fruit stay green and mature late; increasing phosphorus and potassium fertilizer promotes early maturity of oil tea fruit. Therefore, harvesting oil tea fruit should be flexibly controlled, reasonably arranged, and picked at the right time. After the fruit is brought back, pile it for 3-4 d, sun-dry and thresh it, remove impurities, and prepare for pressing.