Camellia oleifera planting techniques

Camellia oleifera likes warmth and is afraid of cold, so it needs plenty of sunshine, otherwise it only grows branches and leaves, resulting in less fruit and low oil content. The following are carefully arranged camellia oleifera planting techniques for everyone. Let's have a look.

Planting techniques of camellia oleifera Ⅰ. general survey

1 economic value

Camellia oleifera is a plant of Camellia of Theaceae, which is the main woody edible oil tree species in southern China. Tea oil is a high-quality and high-grade edible oil deeply loved by the masses. The content of unsaturated fatty acids is more than 90%, mainly oleic acid and linoleic acid. Tea oil is easily absorbed and digested by human body. It does not contain erucic acid and behenic acid which are hard to be absorbed by human body, nor does it contain cholesterol which can raise blood pressure and lead to arteriosclerosis. Long-term consumption can reduce serum cholesterol content and play a role in preventing and treating hypertension and common cardiovascular diseases. Tea oil is resistant to storage and rancidity. It is delicious and fragrant, and is the best oil for cooking food, canning and making cream. Tea oil and its by-products are not only edible, but also widely used in industry, agriculture and medicine.

Camellia oleifera is an evergreen and long-lived tree species. Once planted, the harvest period exceeds 100 years. Camellia oleifera has strong adaptability and drought resistance, and is a pioneer afforestation tree species in the border area of low hills and hilly red soil in southern China. Camellia oleifera blooms in winter and spring with rich colors, especially in autumn and winter with few flowers. It is not only a beautiful ornamental plant, but also an important nectar source tree species. Camellia oleifera is also an excellent fire-resistant tree species.

Therefore, vigorously developing Camellia oleifera production in hilly areas of our province can not only adjust the agricultural industrial structure, increase farmers' economic income, provide high-quality health care oil sources, meet people's growing living needs, but also improve the forest coverage rate in hilly areas. At the same time, Camellia oleifera forest also has many ecological benefits, such as beautifying the environment, purifying the air, regulating the climate, conserving water and soil, and promoting the sustainable development of industrial and agricultural production. According to the calculation, the ratio of ecological benefit to economic benefit of Camellia oleifera forest is 10:3.

2. Distribution and current situation

Camellia oleifera is not widely distributed in the world, and China is its natural distribution center. The horizontal distribution of Camellia oleifera in China is about 65438+08? 2 1? -34? 34? 98 degrees east longitude? 40? - 12 1? 4 1? The whole distribution area spans 18 provinces and cities and 1 100 counties. The amplitude of vertical distribution is mostly 400-800 meters, but it varies with latitude, longitude and topography.

There are several types of camellia oleifera forests in China, such as intensive plantation, semi-wild low-yield forest and naturally distributed mixed forest. Camellia oleifera forest in the main producing areas is mainly artificial pure forest, which is the main body of Camellia oleifera productivity; Semi-wild camellia oleifera forest has extensive management, low yield and poor economic benefits, and is now being gradually transformed; In natural forests, the growth of Camellia oleifera is often inhibited and the yield is very low.

In recent 20 years, the scientific research and production level of Camellia oleifera in China has been continuously improved, improved varieties have developed rapidly, new breakthroughs have been made in asexual propagation technology, clonal afforestation has been widely implemented, high-yield forest standards have been implemented, large-scale low-yield forests have been transformed, and economic benefits have been significantly improved. Especially in recent years, the understanding of the importance of Camellia oleifera forest in the southern ecological location has been strengthened, Camellia oleifera has been regarded as the first choice of eco-economic tree species in the southern hilly areas, and Camellia oleifera has become a new development hotspot for greening barren hills and returning farmland to forests.

At present, the cultivated area of Camellia oleifera in China is 55 million mu, and our province is the central producing area of Camellia oleifera, with a cultivated area of more than 20 million mu and an annual output of 70,000-80,000 tons of oil, ranking first in the country in both area and output.

There are 4,484.9 hectares of camellia oleifera in Changsha county, accounting for 6% of the county's forestry land area, all of which are artificial forests. There are 20 towns and villages in Changsha county, including 2 towns and villages over 667 hectares and 7 towns and villages over 67 hectares. Most varieties are cold dew seeds, followed by first frost seeds; Most trees are middle-aged and elderly people, and they are all conventional varieties. There are few young trees and improved camellia oleifera, with an average annual oil production of 246 tons and only 55 kilograms per hectare. The local people have nearly 300 years of business history and accumulated some experience in camellia oleifera cultivation. (In recent years, 1 10,000 mu is newly built every year, and the speed of changing to 2,000 mu is slow. With the improvement of living standards, people's demand for camellia oleifera is bound to rise, so Changsha County has certain favorable conditions for developing camellia oleifera industry.

Second, biological characteristics.

1 growth and fruiting habits

Camellia oleifera is a small evergreen tree with a life span ranging from decades to hundreds of years. The age at which Camellia oleifera begins to bear fruit varies with different propagation methods. Seedlings began to bear fruit in 5 years, and entered the full fruit stage in 10. Grafted seedlings began to bear fruit in 3 years, and entered the full fruit stage in 6 years. Under good management conditions, the full fruit period can last for 40-50 years.

Root system: Camellia oleifera is a deep-rooted tree species with central axis. The main tree is particularly developed, extending into the ground 1-2m, with few lateral roots and fine roots, and the absorption roots are distributed in the soil layer of 20-50cm. The roots of Camellia oleifera have two growth peaks in a year, which begin to move in mid-February, and the first growth peak appears in March-April, that is, before the rapid growth of new shoots. In September, the second peak of root growth appeared after flower bud differentiation and fruit growth stopped, but before flowering. From February 65438 to February of the following year, the growth was slow, but it did not stop. The root growth of Camellia oleifera has strong water and fertilizer tropism and strong healing and regeneration ability.

Bud: the bud of Camellia oleifera can be divided into terminal bud and axillary bud according to its position at the tip; According to its nature, it can be divided into leaf buds and flower buds. Generally, there are 1-3 terminal buds, and 10 or more, in which 1 is a leaf bud and the rest are flower buds. Generally, there are 1-2 axillary buds, one of which is a leaf bud and the other is a flower bud. The leaf buds are slender and the flower buds are hypertrophy. At first, it was difficult to distinguish flower buds from leaf buds with naked eyes, and it would not be recognized until mid-May. Round and thick flowers are red. Thin, flat and sharp, blue-green leaf buds germinate in the second year.

The law of flower bud differentiation of Camellia oleifera: the distribution of flower buds in spring shoots is related to forest age, management level, crown and different parts of branches. High management level, high flower bud differentiation rate and early differentiation period in fertilization area; On the same plant, there are many flower buds in the middle and upper part of the crown; There are more flower buds at the top of branches; The crown differentiation rate in the south direction is higher than that in the north direction. The differentiation time and differentiation rate of flower buds of different branching types are different. The highest flower bud differentiation rate of long fruit branches is about 38%, but from the whole plant, the flower bud ratio of middle fruit branches is the highest, followed by short fruit branches, and the long fruit branches are the least. This is because the middle fruit branches and short fruit branches account for a large proportion in the whole tree.

Flower bud differentiation process of Camellia oleifera: The flower bud differentiation of Camellia oleifera started in the middle and late June after the growth of spring shoots basically ended, and basically ended in the late August, with the peak of differentiation from the late June to the middle and late September. Due to long-term climatic reasons, there are differences in different places. The flower bud differentiation in the same stand or even on the same plant is also different, which is also the main reason for the long flowering period of Camellia oleifera.

Shoot: The shoot of Camellia oleifera can be divided into spring shoot, summer shoot and autumn shoot according to the flowering season. In the early stage of Camellia oleifera, when the fertilizer and water conditions are good, they often have both. In adulthood, Camellia oleifera mainly shoots in spring and rarely shoots in summer. More than three leaves on a single branch can form flower buds, blossom and bear fruit; The whole plant has an average of 15-20 leaves per fruit to ensure stable and balanced growth. If there are too few leaves, there will be a small year in the second year.

The growth of spring shoots is not only related to the differentiation of flower buds in that year, but also related to the yield of camellia oleifera next year. The number of spring shoots is positively correlated with the fruit yield in the second year.

Flowers: The flowers of Camellia oleifera are bisexual and cross-pollinated. Pollination media are mainly insects, such as bees and butterflies. Camellia oleifera started to bloom in the middle of June 5438+ 10, and it bloomed in June 5438+065438+ 10. The flowering period basically ended in the end of June, 5438+February, and a few of them were extended to February of the following year. The flowering time in a day is usually from 9 am to 2 pm; 1 1 in the morning to 1 in the afternoon is the most abundant, because the temperature is higher at this time, which is beneficial to flowering, pollination and fertilization.

Fruit: After the female flower of Camellia oleifera is pollinated and fertilized, the ovary gradually expands to form young fruit. After the middle of February, the growth stopped because of the low temperature. In March, the temperature rose and young fruits continued to grow. From April to August, the fruit volume increased rapidly. From July to August, fruits grow rapidly. After the middle and late August, the fruit changed from volume increase to quality improvement and oil accumulation. At this time, the oil content of seeds increased rapidly, while the contents of water, starch and sugar decreased gradually, and did not reach 10 in September.

2. Requirements for environmental conditions

Climatic conditions: Camellia oleifera likes warm and humid climate. Generally, the annual average temperature is 14-2 1℃, the average temperature in June is above 3℃, the average temperature in July is below 28℃, and the extreme minimum temperature is-10℃. 10℃ annual active accumulated temperature1500-5000℃; Annual precipitation1000-2200mm, with precipitation concentrated in April-August; Annual sunshine 1800-2200h, frost-free period of more than 200 days.

Temperature has many effects on the growth and development of Camellia oleifera, among which flower bud differentiation and flowering and fruit setting have the greatest influence. The optimum temperature for flower bud differentiation and flowering of Camellia oleifera is 27-29℃ and 14- 18℃. If the temperature is not suitable, the flower bud differentiation rate and fruit setting rate will decrease.

Camellia oleifera is a light-loving tree species, which has certain shade tolerance at seedling stage and young tree stage, but it needs sufficient light after forest formation.

Camellia oleifera has no strict requirements on water conditions, but during the fruit growth and development from August to September, the rainfall is abundant and even, and the site water is sufficient, which is beneficial to fruit growth and oil conversion. Too much precipitation at flowering stage is not conducive to pollination and fertilization, which aggravates flower and fruit drop. Folk proverbs? Dry ball in July, dry oil in August? This is a fact.

Soil conditions: Camellia oleifera is not strict with soil, yellow soil and red soil grow best, followed by yellow red soil and red soil. In production, loose, deep and fertile loam with PH value of 5-6, good drainage and strong fertilizer and water retention should be selected, or cultivated in sandy loam. Camellia oleifera is a calcium-intolerant plant, which cannot grow on neutral soil and calcareous soil.

Topographic conditions: altitude, slope direction, slope position, slope and other conditions have indirect effects on the growth and development of Camellia oleifera. The growth, fruit yield and oil content of Camellia oleifera forest on sunny slope in mountainous area are higher than those of Camellia oleifera forest on shady slope, with early flowering and early fruit maturity. The growth and yield of downhill Camellia oleifera forest are better than that of uphill Camellia oleifera forest. The slope should be gentle, exceeding 25? The growth is not good.

Third, raise seedlings.

1, seedling cultivation

Seed Camellia oleifera directly in the seedbed, cultivate it for 1-2 years, and take out bare-rooted seedlings from the nursery, which is a conventional seedling raising method. Camellia oleifera seedling stage is negative, which needs sufficient water and fertile soil. Nursery should be selected on sloping land with good irrigation and drainage in the southeast, and sandy loam with PH value of 5.5-6.5 is suitable. Camellia oleifera is not suitable for growing in high humidity, poor drainage, sticky board or dry sandy soil. After ploughing the nursery in early winter, apply the decomposed manure evenly, and then rake it flat to make the border. It is necessary to sow rats in winter. Soak seeds for 2-3 days 25 days before spring sowing, accelerate germination in sand bed 18-22 days, and then sow in nursery. Camellia oleifera is planted in a strip with row spacing of 10. 20cm is suitable. Sow about 20,000 seeds and 40 kilograms of seeds per mu. The thickness of covering soil is 1.5-2.0 cm, which is slightly restrained. The seedling height is about 10 cm, and the effective nitrogen fertilizer (0.5? ) Once, when 3-5 true leaves grow, use a shovel to cut off the main root at an oblique angle of 45 degrees below the surface 10- 15cm to promote lateral root rooting. Then apply compound fertilizer (1? ) once. Using half a quantity of bordeaux mixture to control leaf soft rot in spring rain; Saving in high temperature and rainy season 1? Tobuzin for controlling leaf anthracnose. Pay attention to loosening the soil and weeding, so that the soil can keep a certain water content. One-year-old seedlings are as high as 30 cm, the rhizome is 0.25-3.0 cm thick, and the first-class seedlings can reach 9000- 1 1000 plants per mu.

2. Cutting and seedling raising

Cutting propagation is the simplest and most feasible method in asexual propagation, which can breed a large number of improved seedlings for production in a short time, so it is widely used. Spring shoots and summer shoots within the age of 65,438+0 are selected for cutting, with thick and straight buds, sound axillary buds and complete leaves, especially the spring shoots that have just been lignified in that year.

Harvesting cuttings must be cut with sharp branches, and the cutting position is about 1cm above the weak buds at the base of branches (usually above the first or second leaves), so that the cut branches can make full use of the strong axillary buds for propagation.

There are two kinds of cuttings: long spike and short spike. A long spike with 3-5 buds per spike is about 8- 10 cm long. Because of the large leaf area, more photosynthetic products and easy rooting, the survival rate of conventional cutting is high. Short spike 1-2 leaves per spike, 3-5 cm long; The reproductive coefficient is 2-3 times higher than the former, but it needs superior environment and management conditions. When cutting the ear, use a single-sided blade to cut it at a 45-degree angle about 2mm above the axillary bud. The cuts at the middle and end of the ear should be cut into inclined planes, and the cuts should be smooth, so as not to hurt the buds and leaves. Pay attention to moisturizing during ear cutting to prevent wind and sun exposure.

Make a general nursery-style seedbed in a better place, with a bed surface height of15cm, and use 2: 1 yellow mud mixed with sand as the cutting layer. Shading shed must be set up after cutting, the temperature in the shed should not exceed 30℃, and the light transmittance should be around 30%.

Conventional cutting is suitable in summer and autumn, but the cutting effect in summer is the best. A large number of experiments have proved that the best cutting time is from the end of May to June.

3. Cultivation of grafted seedlings

There are many grafting methods of Camellia oleifera. At present, there are subcutaneous grafting, shield bud grafting, cutting grafting, abdominal grafting and bud grafting. Bud grafting? , the specific operation method is:

Selecting seeds to accelerate germination: after harvesting, dry camellia oleifera in the shade, select large seeds (380-440 seeds/kg), store them in wet sand after disinfection, and cover them with film or other covering to accelerate germination.

Selection of nursery land: choose paddy field or dry land with convenient transportation, flat terrain, sufficient light and easy irrigation and drainage as nursery land. After the nursery is selected, the vegetation will be cleared and the soil preparation will begin in mid-March. After applying 50 kilograms of lime and 50 kilograms of compound fertilizer per mu, dig the soil deeply and make a bed after 6-7 days. Bed width is about1.2m.. It is required that the bed surface is flat and the soil is loose. After the seedbed is completed, it can be covered with a layer of yellow mud to reduce the harm of weeds.

Building a shade shed: After the seedbed is ready, build a shade shed with a height of about1.7m.. After shading, cover the seedbed with plastic film to prevent rain washing, keep the seedbed loose, dry and moist, and facilitate grafting and cultivation.

Collection, transportation and storage of scions. When picking, choose branches with full leaves and buds, no pests and diseases, and good growth. During long-distance transportation, the bottom of the box can be covered with absorbent cotton, soaked in water and transported to the nursery, and inserted into a sand bed or kiln in the shade to keep humidity, which can be used for 5-7 days.

Grafting: Generally, the grafting period is from mid-May to late June, when the rootstock has grown to 3-4 cm high and the scion has been semi-lignified. If the seeds germinate too early, a layer of wet sand can be covered on the bud bed to prolong the germination period and thicken the bud anvil; If the seeds germinate too slowly, warm water can be sprinkled every 2-3 days to ensure that the bud stock stage is consistent with the scion stage.

Grafting method: cutting the rootstock, digging out the rootstock seedlings, washing off the sediment, cutting the rootstock 2 cm above the cotyledon, removing the growing points, and then cutting the rootstock longitudinally at the incision, splitting the rootstock in half, with the incision depth of 1.2- 1.5 cm. Pruning: cut one knife on both sides of the lower part of the bud, cut the lower part into a wedge shape of 1.2 cm, and then cut off the upper part of the bud, one leaf and one bud. 1/2 can leave or cut off all the leaves. Cutting: insert the cut scion into the cut of the rootstock to connect the cambium, then wrap the joint tightly with a thong, and then cut off the main root of the rootstock 1/3.

Planting: Planting the grafted seedlings in the seedbed, with the planting density of 60,000 plants per mu, and watering with watering can once after planting.

Follow-up management: the first germination begins about 20 days after grafting, and weeds and dead plants are removed. Germination and impurity removal will continue until September. One month after grafting is the key period of seedling healing, and low temperature, rainy weather or drought will make seedling healing difficult. Low temperature and rainy weather often make the groundwater level rise, and seedlings are prone to root rot, so ditch cleaning and drainage should be done in time. In case of high temperature and drought, the shading degree should be increased, the light should be reduced, and sprinkler irrigation should be carried out in time to reduce the temperature of the nursery. After transplanting seedlings for half a month, potassium dihydrogen phosphate can be sprayed for 2-3 times, which can prevent Fusarium wilt, root rot and cutworms in the nursery and promote seedling growth. When the seedlings are grafted for about 40 days and the seedlings have survived, the moisturizing cover can be removed and the shade shed can be removed after the Millennium Festival.

In order to improve the quality of seedlings and ensure the survival rate of afforestation, in the first ten days of May of the following year, when the growth of spring shoots nearly stopped, measures were taken to remove the heart and fix the stem to promote the branching of seedlings. The ground diameter was more than 0.4 cm, the height of seedlings was 40 cm -45 cm, and the root system was developed.

Fourth, afforestation technology.

1, afforestation site selection

Camellia oleifera is an acidic tree species, which is generally suitable for growing in soil with pH value of 5-6.5. Acidic soils such as Tiemangji, Yingshanhong, Vaccinium bracteatum, Rhus sumac and Imperata showed that the low hills with lush plants could be used as afforestation sites for Camellia oleifera.

Camellia oleifera is a kind of tree species that gradually changes from semi-shade to sun in the process of individual development. After entering adulthood (10 years), due to a large number of results, vegetative growth and reproductive growth alternate, and the demand for direct light is very urgent, such as insufficient light, which has a great impact on the yield of Camellia oleifera. The main purpose of planting Camellia oleifera is to produce more fruits, seeds and oil, so afforestation must choose sunny and semi-sunny slopes. Especially in mountainous areas with mountainous peaks, we should pay special attention to the choice of woodland slope direction, and should choose south, east or southeast.

Camellia oleifera should be cultivated frequently in intertillage, and the soil in forest land should be excavated and cultivated in different degrees at each growth stage. The greater the slope, the faster the soil erosion. In order to conserve water and soil and conserve water resources, Camellia oleifera should choose sloping land or gentle slope below 25 degrees for afforestation.

2. Soil preparation

There are three kinds of soil preparation methods for Camellia oleifera: full reclamation, strip soil preparation and block soil preparation, which can be selected according to forest land, management level, labor input and ecological environment protection. Full reclamation is suitable for afforestation land with slope less than 15 degree and not easy to cause soil erosion. Steep slopes, broken slopes and? Four sides? Planting trees can be used. Soil preparation should be carried out three or four months before afforestation, which is beneficial to soil weathering and cave soil implementation. The planting hole should be 80? 80? 80 cm pit, combined with the pit filled with enough base fertilizer, base fertilizer should be fully mixed with backfill soil, and the hole filling should be more than 20 cm above the ground.

3. Planting density

The planting density is mainly determined according to the biological characteristics, site conditions and commercial variety model of tree species, which is generally 60? About 120 strains. The fertile land is sparsely planted and the soil is thin and dense; Sparse planting at the foot of the mountain and dense planting at the top of the mountain; Sparse planting on gentle slope and dense planting on steep slope; The experience of intercropping and non-intercropping and planting density, planting density of first frost varieties and planting density of cold dew varieties are worth popularizing.

4, seedling planting

Camellia oleifera is an evergreen broad-leaved tree species, and its seedlings have long main roots and few lateral roots. Afforestation in sunny days and dry seasons is most likely to cause water loss of seedlings, leading to afforestation failure. The survival rate of Camellia oleifera afforestation is closely related to air humidity and soil humidity. The survival rate of afforestation in sunny days is very different from that in rainy days, so the survival rate is high when planting. It is rainy in spring, with high air humidity and wet soil. Beginning of spring? Where to? Scared? During this period, it is most suitable to choose cloudy days or light rain for afforestation before germination.

What is the basis of afforestation? Three buries, two steps and one seedling? The principle of. Be sure to plant it firmly and practically. For large holes on flat slopes, after planting, the base stems should be piled into steamed buns with loose soil to prevent the cave soil from sinking and accumulating water in rainy season, resulting in waterlogging death. The suitable planting depth of seedlings is 1- 1.5cm beyond the original nursery.

Direct seeding afforestation is a simple and labor-saving method, which can quickly complete large-scale afforestation tasks.

5. Tending management

The management of young forest is mainly intertillage weeding to solve the problem that seedlings and weeds compete for light, water and fertilizer. 3 times, at the same time, intercropping cultivation can be used instead of caressing; Secondly, tree-type cultivation, namely, timely drying and coring, and controlling branch elongation, so as to cultivate high-yield tree-type with compact crown and open tree shape; In order to ensure the premature delivery and high yield of young forests, appropriate fertilization measures should be taken. The forest stage is the period when Camellia oleifera begins to bear fruit, and it is also the most valuable period for Camellia oleifera management. In order to ensure the high and stable yield of adult Camellia oleifera, it is necessary to shovel and weed once a year in summer and dig deep every three years in winter. In addition, reasonable fertilization should be carried out according to soil fertility, tree age, tree potential and fruiting year.

Five. Transformation of low-yield forest

Low-yield Camellia oleifera forest is a very common problem in Camellia oleifera production, and its causes are both historical and practical. The historical reason is the traditional seedling propagation, which leads to a mixed variety, a large proportion of inferior plants and a large difference in plant yield. After decades or even hundreds of years, many camellia oleifera forests have unreasonable stand structure, uneven density, mixed generations, aging stands and poor natural regeneration ability. The realistic reason is that we don't know enough about camellia oleifera production, and take camellia oleifera as? Show money? Extensive management, barren forest land, poor nutrients, serious pests and diseases, improper tending management and premature logging. The transformation of low-yield camellia oleifera forest is an effective way to increase production in a short period of time with less investment and quick results. Different stands have different transformation methods, and all kinds of measures cooperate with each other and can achieve the best effect by comprehensive application. The main technical methods for transformation of low-yield camellia oleifera forest are as follows:

(1) Forest land clearing

Forest land clearing refers to the thorough cutting of shrubs, weeds, host plants and other miscellaneous timber forests and economic fruit trees in Camellia oleifera forest. For mixed irrigation forest land, it needs to be cleared at one time, which is beneficial to subsequent operations. When clearing the forest land, it is necessary not only to remove miscellaneous irrigation, but also to cut off the old, disabled and diseased plants of Camellia oleifera.

(2) thinning and filling

For too dense stands and places, we must be cruel and sparse. The experiment shows that the more thorough thinning is, the better the effect is, which not only does not affect the yield, but also increases the yield. Please pay attention to the following aspects when refining:

1. Cut down small trees under the forest.

2. Cut down trees with unreasonable tree structure.

3. Remove unfruitful or unfruitful trees. Through thinning, the canopy density is adjusted between 0.7 and 0.8 to maintain a reasonable light transmittance in the stand.

For sparse forests, replanting is needed to make full use of soil fertility space, improve the production potential per unit area and increase the rate of improved varieties of forests.

③ Pruning

Pruning is necessary in order to form a reasonable tree structure, improve ventilation and light transmission conditions in the forest and facilitate other operations. Pay attention to pruning: 1, mainly thinning. Pruning the lower branches is the main method, that is, pruning the branches and brightening the feet to make the trees empty, which is convenient for reclamation, fertilization, ditching and other operations. 2, according to the tree, cutting dense and keeping sparse, weakening and retaining strong, forming a reasonable forest structure. 3. Avoid cutting branches with machetes, especially big branches, and cut branches with a saw knife to avoid damaging trunk bark and causing pests and diseases.

④ Excavation and reclamation

Reclamation of Camellia oleifera can greatly promote the growth and development of Camellia oleifera and make the output increase exponentially. Camellia oleifera in China has a large area and extensive management, and it has been in a barren or semi-barren state for a long time. Therefore, we must vigorously promote reclamation. Attention should be paid to when recycling:

1, the depth is more than 20 cm.

2, to dig deep reclamation.

3. Advocate deep ploughing and reclamation, and turn the clods upside down. First, it is conducive to the deep burial and decay of litter and other falling objects, and second, it is conducive to the miscellaneous irrigation of roots.

4. Only by adhering to the habit of deep digging once every three years and shallow hoeing once a year can we consolidate the results of deep digging and reclamation. Especially after deep digging in autumn and winter in the first year, a shallow hoe must be carried out in summer in the second year to effectively control weeds and loosen soil.

5) Digging slub ditch

Camellia oleifera forests in China are mostly distributed in subtropical monsoon region, with more rainy seasons in spring and summer and serious soil erosion. High temperature and drought are not conducive to the growth and development of Camellia oleifera. Digging bamboo joint ditch is an important measure to prevent soil erosion and improve the ability of forest land to preserve water, soil and fertilizer. Standards and requirements of slub ditch:

1. Excavate along the horizontal line around the mountain. The bottom of the ditch is 50 cm wide and 40 cm deep.

2. The ditch spacing depends on the slope of woodland. The spacing between upper and lower ditches with a slope greater than 15 degree is 8m, and the spacing between ditches below 15 degree is 10m.

3. If conditions permit, the stand with regular row spacing can gradually build horizontal ladder soil, but even if the horizontal ladder soil is built, the inner slope of the ladder surface should be dug and stored in bamboo ditch to prevent soil erosion.

4. According to the technical requirements, the stand with a slope greater than 25 degrees can take various forms such as digging fish scales pits according to the site conditions. The general principle is to ensure that water, soil and fertilizer are not lost or as little as possible.

（6）

A large area of Camellia oleifera forest, long-term barren, extensive management, poor growth and low yield, has a lot to do with the serious lack of fertilizer in the soil. Therefore, the combination of reclamation and application of a certain amount of fertilizer is the key technical measure to improve the yield of Camellia oleifera.

Fertilization principle:

1, mainly phosphorus and potassium fertilizers in big years and nitrogen fertilizers in small years.

2. Organic fertilizer is dominant in autumn and winter, and quick-acting fertilizer is dominant in spring and summer.

3. Use more big trees and less small trees.

4. Apply more high-yield trees, and apply less or no trees.

5. Trees with strong growth potential should apply less nitrogen fertilizer and more phosphorus and potassium fertilizer, while trees with weak growth potential should apply more nitrogen fertilizer.

6. Increase the application of phosphorus and potassium fertilizer to the stands with good opposition conditions and strong growth potential, and increase the application of nitrogen fertilizer to the trees with poor opposition conditions and weak growth potential.

Fertilization method: at the uphill position, a semi-circular ditch is protruded along the outer edge of the crown, and the depth of the ditch is about 15cm, then the ditch is applied and the soil is covered. Note: Do not apply fertilizer on the surface or pile it together for root system to absorb.

Six, pest control

1, main diseases and control methods

There are more than 20 diseases of Camellia oleifera, among which anthracnose, soft rot and bituminous coal disease are the main hazards to production. Camellia oleifera diseases should be mainly controlled by forestry technology, and forest management should be strengthened to clean the forest environment, keep the forest ventilated and transparent, and reduce humidity. Nitrogen fertilizer should not be applied at the onset stage, and phosphorus fertilizer and potassium fertilizer should be added to improve the disease resistance of plants. Spraying 1% bordeaux solution for protection after new buds grow in early spring to prevent primary infection. At the initial stage of the disease, 50% thiophanate-methyl wettable powder 500? 800 times solution or Baume degree 0.3 stone sulfur mixture for prevention and control.

2, the main pests and control methods

The pests that harm camellia oleifera mainly include inchworm, tea borer, camellia oleifera borer and longicorn beetle. Forestry technical measures that can be used for prevention and control include shoveling insects in summer and killing pupae and larvae in winter, artificial capture and light trapping moths; Attracting beneficial birds to prey on pests, applying Beauveria bassiana, Bacillus thuringiensis and other biological control measures are the direction of pest control in Camellia oleifera. Drug control is only used when there is a big pest, and it is generally not used or used as little as possible.

Planting techniques and propagation methods of Camellia oleifera

Camellia oleifera is propagated by seeds, cuttings or grafting. In order to maintain the excellent characters of parents, cuttings or grafting are often used to raise seedlings, and then planting and afforestation are carried out. The best afforestation season is from beginning of spring to Jingzhe, also in June+10. Direct seeding afforestation is best carried out in winter.

Sowing and seedling raising

Seeding and seedling raising of Camellia oleifera can be carried out in winter and spring, and the method of strip sowing is more suitable. Generally, paddy soil, heavy clay and alkaline reactive soil are not suitable for Camellia oleifera growth, so it is best to choose a slightly acidic soil distribution area with flat terrain, shelter from the wind and the sun, fertile texture and good water retention and drainage performance. Prepare the seedbed before sowing and apply sufficient base fertilizer. After sowing, cover it with a layer of fine fertile soil and a layer of thin grass to keep the soil moist and make the seeds germinate and emerge as soon as possible. When the seeds germinate and are unearthed, it is necessary to uncover the thin grass on cloudy days or in the evening, and weed and loosen the soil in time.

Cutting seedling

Although camellia oleifera can be cut in spring, autumn and Xia San, it is best to cut in summer. Harvest is more suitable for early morning. Branches with lignified leaves, full axillary buds and no pests and diseases should be selected, and then cut into cuttings with one leaf and one bud about 4 cm long. Before cutting, it needs to be treated with ABT rooting powder to promote rooting; When cutting, make sure that the cuttings are upright, the leaves are facing up, and the spacing between plants is about 5cm,15 cm; After the cutting is completed, it is necessary to water and pay attention to building a shade shed.

Generally, the roots of Camellia oleifera will gradually heal within 1 ~ 2 months after cutting, but before rooting, the cuttings should be watered in time to accelerate the internal cell division and sprout new roots as soon as possible. After Camellia oleifera takes root, it is necessary to uncover the shade shed in the morning and evening or on cloudy days to increase the light and promote the growth and development of Camellia oleifera.