First, improved varieties of camellia oleifera.
At present, the main cultivated varieties in our region are common camellia oleifera, small fruit camellia oleifera and Vietnamese camellia oleifera. Among the common camellia oleifera, Cenxi soft branch camellia oleifera is recognized as an excellent farm variety, which has passed the examination and approval of national improved varieties, bearing fruit 2 ~ 3 years earlier than the common variety, and its yield is 1 ~ 2 times higher. It blooms in 3 ~ 4 years after planting, and enters the rich period in the seventh year, with an oil yield of more than 450 kg per hectare. Two clones, Cenruan No.2 and Cenruan No.3, have been selected and widely planted in production. In addition, there are many excellent clones, such as Guiwu 1, 2, 3, 4 and 5, which were selected by Guangxi Academy of Forestry.
Second, the growth conditions and ecological characteristics
Camellia oleifera is an evergreen tree species, which is suitable for planting in various soils and can grow normally even in barren land.
The roots of Camellia oleifera generally begin to move in mid-February, the first peak appears in March-April before the rapid growth of new shoots, and the second peak appears in September. The root system of Camellia oleifera has strong water and fertilizer tropism, strong healing power and regeneration power. It has obvious apical advantage, bud germination begins in March and the peak of differentiation is in June-July. The tender branches of adult trees coexist with vegetative growth and reproductive growth, and the spring shoots are flowering and fruiting branches; Flowers are bisexual and mainly pollinated by insects. Flowering period is from mid-June 65438+ 10 to late February 65438+2, and flowering period is 165438+ 10. Cross-pollination, pollination and fertilization on the first or second day of flowering period have the highest seed setting rate. The fruit maturity of Camellia oleifera is 65438+September, which is divided into cold dew seeds and first frost seeds. There is a phenomenon of "holding a child and getting pregnant" in the same period of flowers and fruits.
Third, high-yield cultivation techniques of Camellia oleifera
1. Selection of afforestation sites
The woodland is selected from mountain red soil and yellow red soil, with a PH value of 5-6.5; Altitude100 ~ 500m; Choose sunny slope and semi-sunny slope, and the woodland slope is best facing south, east or southeast; It is appropriate to use the middle and lower slopes with a slope below 25 degrees.
2. Soil preparation
Soil preparation methods include complete reclamation (slope
3. Afforestation methods
Afforestation with improved seedlings on the mountain. Afforestation is mainly based on afforestation, using 1 ~ 2-year-old clonal grafted seedlings or 1 year-old improved seedlings. The annual seedling height is more than 20 cm, and the biennial seedling height is more than 40 cm. For seedlings that need long-distance transportation, the main roots and dense branches and leaves should be trimmed appropriately, and soil or yellow roots should be brought as much as possible.
Planting and afforestation season mainly depends on local climate conditions and seedling cultivation, and is generally suitable for planting trees in rainy season or cloudy or light rain weather in February-April. The planting density can be 2.5×2.5m, 2×2.5m and 2×3m. Afforestation should be based on the principle of "three buries, one lift and three steps". For the big hole on the flat slope, after planting, the base stem should be piled into steamed bread with loose soil to prevent water from depositing in the hole soil in rainy season and causing waterlogging death. The planting depth of seedlings should be above 1 ~ 1.5 cm in the original nursery.
4. Tending management
(1) young forest
Young tree shaping: in the third year after afforestation, when the height of the tree is 70 ~ 80 cm, in early spring, choose to leave a few strong main branches around the trunk, cut off the branches of diseases and insect pests, properly trim the foot branches, and remove sprouting in time after pruning.
Intertillage weeding and fertilization: three years before afforestation, intertillage weeding once a year in late spring, early summer and early autumn, intertillage weeding once a year from the fourth year to the sixth autumn, and deep digging once every three years. Nitrogen fertilizer is dominant, and phosphorus fertilizer is suitable. In spring, quick-acting fertilizer, urea 50- 150g/ plant, long-acting fertilizer and phosphorus fertilizer 100- plant are applied in winter.
(2) Forest formation
Plastic decoration. Pruning according to trees, shaping according to branches, thinning and maintaining strength, pruning at old age and pruning at young age, to form a round-headed crown and a three-dimensional natural happy crown.
Dig deep into reclamation, improve soil conditions and improve ventilation and water conservation performance. Deep digging and reclamation in winter and spring can improve soil fertility, store water, reduce pests and diseases, promote root extension and increase yield. The general depth is 20 ~ 25 cm, and the scientific method is "digging once every three years (deep digging) and ploughing once a year". In order to prevent soil erosion, full reclamation is adopted below 15o slope, and enclosed reclamation, cave reclamation and bench reclamation are adopted above 15o slope.
Rational fertilization to improve soil fertility. Camellia oleifera has the characteristics of "holding a baby". Flowers and fruits are inseparable from branches all year round. To achieve the goal of high and stable yield, it is necessary to supplement fertilizer sources. According to the soil nutrient content and the growth and fruit of Camellia oleifera, different kinds of fertilizers were applied in different periods. Phosphorus and potassium fertilizer are mainly used in big years, and nitrogen fertilizer or compound fertilizer is added in small years. Organic fertilizer is mainly used in autumn and winter, and quick-acting fertilizer is mainly used in spring and summer. Phosphate fertilizer is mainly applied in the full fruit stage, nitrogen fertilizer is applied appropriately, and compound fertilizer is applied to each plant.
Step 5 control pests and diseases
We must implement the policy of "prevention is more important than cure", do a good job in forecasting pests and diseases on the basis of afforestation technical measures, and take comprehensive control measures with biological control as the main and chemical control as the supplement in time once pests and diseases occur.