Material-saving-free cultivation technology for erythrophloeum ferrugineum

Abstract

The invention belongs to the field of cultivation of precious tree species, namely, erythrophloem artichoke wood forests, and particularly relates to a material-saving-free cultivation technology for erythrophloem artichoke. In order to solve the problems of many branches, unobvious trunks, low outturn percentage, many wood knots in main outturn sections and poor quality in the early stage of an existing artificial evergreen forest, the invention provides the following scheme that the method comprises the following steps: (1) environment regulation and control of early-stage afforestation grafting: S1, environment control: uniform intermediate cutting and different-age mixing, and block intermediate cutting and different-age mixing; s2, associated tree species are selected, wherein the associated tree species and fast-growing tree species are mixed at the same age; (2) a young forest stage tending management stage: S3, afforestation and tending management: the first three years after afforestation is the afforestation tending management stage, and the main technology comprises afforestation density, tending, fertilization and bud picking and pruning; the method can improve the early-stage trunk formation of the erythrospermum erythrorhizon forest, inhibit the number of knots, reduce the cost, and improve the wood yield and quality.

Description

Technical Field

[0001] The invention relates to the technical field of euphorbia pulcherrima cultivation, in particular to a euphorbia pulcherrima knot-free wood cultivation technology. Background Art

[0002] Erythrophleum fordii Ol iv., commonly known as "iron wood", is a tall evergreen tree of the genus Erythrophleum in the family Saccharumaceae, which can reach a height of 30m and a breast diameter of more than 1m. It is the only species of this genus that is naturally distributed in my country (Flora of China). The natural distribution range of Erythrophleum fordii is mainly between 16° and 24°N. The northern edge is in my country, mainly including Guangxi and central and southern Guangdong, southern Fujian and Taiwan (Zhao Zhigang et al., 2009), and the southern edge is in northern Vietnam and Laos. Erythrophleum communities are one of the few plant communities dominated by leguminous plants. Erythrophleum has excellent quality and a wide range of applications. Due to long-term over-exploitation and the gradual replacement of natural forests by cash crops and fast-growing tree plantations, natural forest resources are almost exhausted. It has been listed as a national second-level key protected plant and has been included in the Red List of Endangered Species of the World Conservation Union (IUCN).

[0003] The eucalyptus is a major precious tree species in my country and a national first-class wood. The heartwood and sapwood of the eucalyptus are clearly distinguished. The sapwood is light yellow or yellowish brown, and the heartwood is reddish brown or chestnut brown. It is glossy, has no special smell, and has slightly obvious growth rings. The heartwood is mainly used. It is a high-grade precious wood with delicate patterns and chicken wing patterns. The air-dry density is 0.93-0.97g / cm3, the compressive strength along the grain is 75.0-99.0MPa, and the bending strength is 134.0-170.2MPa. The wood has high strength and hardness. It dries well naturally and is not easy to crack. It has strong corrosion resistance and ant resistance. It is difficult to cut and the cut surface is not easy to plane. It has good gloss after painting and good adhesiveness. It is easy to crack when nailed. It is suitable for high-end furniture, solid wood floors, construction, bridges, ship materials, etc. (Jiang Zehui and Peng Zhenhua, 2001; Xu Feng, 2008).

[0004] The application history of eucalyptus can be traced back to the Qin Dynasty. It was the main material for Cantonese furniture in the Ming and Qing Dynasties. The Palace Museum has a collection of it. The large-diameter wood of eucalyptus with a diameter of more than 30 cm is priced at 20,000 to 30,000 yuan per cubic meter. In recent years, it has been promoted in many places in Yunnan, Guizhou, Guangxi, Guangdong and southern Fujian.

[0005] The terminal buds of young euphorbia chinensis forests are easily damaged by the litchi moth (Cryptophlebia ombrodelta L.), which is the main limiting factor for knot-free timber cultivation. The insect can reproduce five generations a year in South China, and euphorbia chinensis has a strong budding ability. New buds are constantly damaged, causing the tree species that naturally grow as tall trees to grow into shrubs in artificial pure forests. In the early stage (7-10 years after afforestation), the growth performance is extremely poor, the main trunk is not obvious, and it is difficult to achieve the cultivation goal. In the middle and late stages, due to the influence of forest competition, although the main trunk can be formed, the height under the branches is low, the branches are large, and the wood utilization rate is low, which does not meet the requirements of high-quality cultivation.

[0006] The main use of solid wood is in the case of logs, and knots are log defects (GB / T 18000-1999 Wood Defect Atlas), which affect the log quality grade (GB / T 144-2003 Log Inspection). GB / T4822-1999 Sawn Timber Inspection stipulates that the number of live and dead knots within 1m of any length of wood is as follows: no more than 3 for special-grade wood, no more than 6 for first-grade wood, no more than 8 for second-grade wood, and no limit for third-grade wood.

[0007] From the analysis of tree trunks, it can be seen that the lower trunks (6-8m) with the highest yield and the best quality have many knots. The number of knots in pure forests without pruning management can be up to more than 8, and the trunk shape is poor and zigzag, with a low yield, which seriously affects the value of the wood and the realization of cultivation goals. Summary of the invention

[0008] The purpose of the present invention is to solve the shortcomings of the prior art that the early branches of the artificial eucalyptus tree forest are many, the main trunk is not obvious, the yield rate is low, the main yield section has many knots and the quality is poor, and a knot-free wood cultivation technology for eucalyptus tree is proposed.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] A technique for cultivating knot-free wood of euphorbia pulcherrima, comprising the following steps:

[0011] S1. Environmental regulation in the early stage of afforestation:

[0012] Environmental control: uniform thinning and mixed planting of uneven ages, block thinning and mixed planting of uneven ages;

[0013] Selection of companion tree species: Mix with fast-growing tree species of the same age;

[0014] S2, Young forest cultivation and management stage:

[0015] Afforestation and tending management: The first three years after afforestation are the afforestation and tending management period. The main technologies include afforestation density, tending, fertilization, and bud removal and pruning.

[0016] Bud removal and pruning: In the first three years, bud removal is carried out once at the end of the first year of cultivation. In the second and third years, bud removal and pruning are carried out once in spring and autumn and winter respectively.

[0017] Pruning: Pruning is carried out every 1-2 years from the 4th to the 7th year. In the 7th year, the trunk of the target tree is obvious, and the forest canopy density reaches a level that inhibits the germination of lateral buds, laying a good foundation for the cultivation of large-diameter knot-free timber in the later stage.

[0018] S3. Pest and disease control: After the loblolly trees are planted, they should be monitored for pests and diseases and controlled in a timely manner.

[0019] Preferably, in S1, uniform thinning and planting density: the canopy density after uniform thinning is controlled at 0.5-0.6, and the planting density is recommended to be 3-4m×4m, i.e. 42-56 plants per mu; block thinning and planting density: the thinning area is controlled at 300-500m 2 The recommended planting density is 3m×3-4m, that is, 56-74 plants per mu.

[0020] Preferably, in S1, mixed forest with fast-growing tree species: fast-growing tree species include eucalyptus, birch and acacia sempervirens. These tree species grow fast in the early stage and can quickly form a forest stand environment. In the later stage, fast-growing tree species are in the upper layer. The branches and leaves of the tree species are relatively sparse and the light transmittance is high, which is conducive to forming a forest stand environment suitable for the development of loblolly trees. The planting density is recommended to be 2-3m×3m, that is, 74-111 plants per mu; mixed mode 1: row mixed, fast-growing tree species 2-4 rows: loblolly trees 1 row, loblolly trees account for 20-40%; mixed mode 2: block mixed loblolly trees planting area 100-400m 2 , the block spacing is greater than 20m, and the area of ​​​​eucalyptus planting accounts for 20-40% of the afforestation land.

[0021] Preferably, in S2, afforestation includes digging holes of specifications, and the hole specifications are 40-50 cm long × 40-50 cm wide × 30-40 cm deep. The afforestation time is the early spring rainy season, and afforestation can also be carried out in the winter rainy season if conditions permit.

[0022] Preferably, the fertilization is specifically as follows: applying base fertilizer according to soil fertility, with a ratio of 0.5-1.5kg of organic fertilizer, 0.5-0.75kg of calcium magnesium phosphate fertilizer, and 0.25-0.5kg of compound fertilizer;

[0023] Strip weeding is carried out once in April-June and September-November each year, with a forest belt width of 0.8-1.2m, followed by topdressing;

[0024] According to the development characteristics of the trees and the need to save fertilizer, the amount of topdressing is 50-100g of compound fertilizer in the first year; in the spring of the second and third years, topdressing is urea, 100-150g and 150-200g respectively; in the autumn of the second and third years, topdressing is compound fertilizer, with the amount of 150-200g and 200-250g respectively.

[0025] Preferably, in S3, according to the site and forest stand growth conditions, a 6-8 meter section without side branches is eventually formed. After the forest belt is cleared, bud removal and pruning are carried out. The new buds on the side branches are broken off by hand before they are lignified. At this time, the branch epidermis is white-green and partially red. The leaves are not unfolded. When they are unfolded, the semi-lignified and lignified branches with bright green epidermis and brown base cannot be bud-removed and need to be cut off with a knife or pruned with branch shears / high branch shears. Callus cream needs to be applied to incisions larger than 2 cm, and pruning should be carried out before the diameter of the branch base reaches 1.5 cm.

[0026] Preferably, in S4, the main disease of the seedling stage of the loblolly is damping-off disease, and the prevention and control method is: before sowing, the soil is disinfected by watering with 40% formalin 2.5g / L solution.

[0027] Preferably, in S4, the main insect pests are the stem borers, and the method for preventing and controlling the stem borers can be to spray 1g / L of dimethoate solution once a week for 4 consecutive times.

[0028] Preferably, in S2, the afforestation land is selected to be acidic sandy loam or light clay with a thick soil layer below 600m above sea level, and grows in dense forests or sparse forests in mountains.

[0029] Preferably, in S2, before planting, the seeds of the Euphorbia obesa are placed in boiling water at 80-100°C and stirred until the water temperature drops to a suitable level, or soaked in concentrated sulfuric acid for 10 minutes, and then the colloid on the surface of the seeds is washed off with clean water, and then the treated seeds are soaked in clean water for 12 hours.

[0030] In the present invention, the beneficial effects of the knot-free wood cultivation technology of the eucalyptus tree are:

[0031] Improve early trunk formation: can effectively control the incidence of insect pests by 60-80%, reduce the trunk splitting rate by more than 80%, and achieve 100% trunk formation rate in the target section.

[0032] Suppress the number of knots: the lateral branch germination rate decreases by 40-60%, the height under the branches increases by 3-4 times, the comprehensive effect is improved by about 80%, and the wood grade can be improved from second or third grade to first or special grade.

[0033] The cost of early bud pruning is 50-100 yuan / mu, and the cost of later large tree pruning is 400-500 yuan / mu, which can save about 80% of the cost. Moreover, the wounds from pruning large trees heal slowly and are easily infected by pathogens, forming large dead knots and low-grade wood. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A flow chart of a technique for cultivating knot-free wood of euphorbia pulcherrima proposed by the present invention;

[0035] Figure 2 This is a state diagram of severe branching, where the main trunk is not obvious and the branches are dense;

[0036] Figure 3 This is a state diagram with fewer branches, unclear apical dominance, and low branch height;

[0037] Figure 4 This is a state diagram where the top advantage is not obvious;

[0038] Figure 5 A state diagram with a clear main trunk and reasonable branch height;

[0039] Figure 6 A state diagram with a clear main trunk and few branches;

[0040] Figure 7 It is a leaf bud diagram;

[0041] Figure 8 For the branch buds - the buds can be wiped out;

[0042] Fig. 9 For the bud map;

[0043] Fig.10 This is a trunk bending diagram of a large tree pruning stand (10 years old) in a conventional afforestation management stand. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0045] Embodiment 1

[0046] Reference Figure 1-10 , a technique for cultivating knot-free wood of euphorbia cerasifera, comprising the following steps:

[0047] S1. Environmental regulation in the early stage of afforestation:

[0048] Environmental control: uniform thinning and mixed planting of uneven ages, block thinning and mixed planting of uneven ages;

[0049] Selection of companion tree species: Mix with fast-growing tree species of the same age;

[0050] S2, Young forest cultivation and management stage:

[0051] Afforestation and tending management: The first three years after afforestation are the afforestation and tending management period. The main technologies include afforestation density, tending, fertilization, and bud removal and pruning.

[0052] Bud removal and pruning: In the first three years, bud removal is carried out once at the end of the first year of cultivation. In the second and third years, bud removal and pruning are carried out once in spring and autumn and winter respectively.

[0053] Pruning: Pruning is carried out every 1-2 years from the 4th to the 7th year. In the 7th year, the trunk of the target tree is obvious, and the forest canopy density reaches a level that inhibits the germination of lateral buds, laying a good foundation for the cultivation of large-diameter knot-free timber in the later stage.

[0054] S3. Pest and disease control: After the loblolly trees are planted, they should be monitored for pests and diseases and controlled in a timely manner.

[0055] In this embodiment, in S1, uniform thinning and planting density: the canopy density after uniform thinning is controlled at 0.5, and the planting density is recommended to be 3m×4m, that is, 42-56 plants per mu; block thinning and planting density: the thinning area is controlled at 300m 2 The recommended planting density is 3m×3m, that is, 56 plants per mu.

[0056] In this embodiment, in S1, mixed forest with fast-growing tree species: fast-growing tree species include eucalyptus, birch and acacia nigra. These tree species grow fast in the early stage and can quickly form a forest stand environment. In the later stage, fast-growing tree species are in the upper layer. The branches and leaves of the tree species are relatively sparse and the light transmittance is high, which is conducive to forming a forest stand environment suitable for the development of eucalyptus species. The planting density is recommended to be 2m×3m, that is, 74-111 plants per mu; mixed mode 1: row mixed, 2 rows of fast-growing tree species: 1 row of eucalyptus, eucalyptus accounts for 20%; mixed mode 2: block mixed eucalyptus planting block area 100m 2 , the block spacing is greater than 20m, and the area of ​​​​eucalyptus planting accounts for 20% of the afforestation land.

[0057] In this embodiment, in S2, afforestation includes digging holes according to specifications, and the hole specifications are 40-50 cm long × 40-50 cm wide × 30-40 cm deep. The afforestation time is the early spring rainy season, and afforestation can also be carried out in the winter rainy season if conditions permit.

[0058] In this embodiment, fertilization is specifically as follows: base fertilizer is applied according to soil fertility, with a ratio of 0.5 kg of organic fertilizer, 0.5 kg of calcium magnesium phosphate fertilizer, and 0.25 kg of compound fertilizer;

[0059] Strip weeding is carried out once in April-June and September-November each year, with a forest belt width of 0.8-1.2m, followed by topdressing;

[0060] According to the development characteristics of the trees and the need to save fertilizer, the amount of topdressing is 50g of compound fertilizer in the first year; in the spring of the second and third years, topdressing is urea, 100g and 150g respectively; in the autumn of the second and third years, topdressing is compound fertilizer, with the amounts of 150g and 200g respectively.

[0061] In this embodiment, in S3, according to the site and forest stand growth conditions, a 6-8 meter section without side branches is eventually formed. After the forest belt is cleared, bud removal and pruning are carried out. The new buds on the side branches are broken off by hand before they are lignified. At this time, the branch epidermis is white-green, partially red, and the leaves are not unfolded. When they are unfolded, the semi-lignified and lignified branches with bright green epidermis and brown base cannot be bud-removed and need to be cut off with a knife or pruned with branch shears / high branch shears. Callus cream needs to be applied to incisions larger than 2 cm, and pruning should be carried out before the diameter of the branch base reaches 1.5 cm.

[0062] In this embodiment, in S2, the afforestation land is selected to be acidic sandy loam or light clay with a thick soil layer below 600m above sea level, and is grown in dense forests or sparse forests in mountains.

[0063] In this embodiment, in S2, before planting, the seeds of the Euphorbia obesa are placed in boiling water at 80°C and stirred until the water temperature drops to a suitable level, or soaked in concentrated sulfuric acid for 10 minutes, and then the colloid on the surface of the seeds is washed off with clean water, and then the treated seeds are soaked in clean water for 12 hours.

[0064] In the present embodiment, the main disease of the seedling stage of the loblolly is damping-off. In the early stage, yellow water-soaked spots appear on the rhizome, which gradually expand until the whole plant necrotizes. There are white mycelium in the necrotizing part, and the diseased plant has a slight odor. The control method is: 40% formalin 2.5g / L solution is used for soil disinfection before sowing, or 40g / m3 of carbendazim (50% wettable powder, the same below) is mixed with soil; 2g / L liquid of multibacteria is used for soaking for 30min; 2g / L of carbendazim, 1.43g / L of 70% mancozeb are used in the seedling stage; 1.33g / L solution of thiophanate-methyl (70% wettable powder) is sprayed on the seedlings.

[0065] The main pests are the Spodoptera exigua, etc. The main pest in the seedling stage of the eucalyptus is the eucalyptus moth. It harms the seedlings, mainly laying eggs on the buds. After hatching, the larvae bore into the pith of the young buds from the leaf axils, eating from top to bottom, sap and gum flow out of the boreholes, and the upper part of the damaged branches dries up. The method of preventing and controlling the moth is to spray 1g / L of dimethoate solution once a week for 4 consecutive times.

[0066] Embodiment 2

[0067] A technique for cultivating knot-free wood of euphorbia pulcherrima, comprising the following steps:

[0068] S1. Environmental regulation in the early stage of afforestation:

[0069] Environmental control: uniform thinning and mixed planting of uneven ages, block thinning and mixed planting of uneven ages;

[0070] Selection of companion tree species: Mix with fast-growing tree species of the same age;

[0071] S2, Young forest cultivation and management stage:

[0072] Afforestation and tending management: The first three years after afforestation are the afforestation and tending management period. The main technologies include afforestation density, tending, fertilization, and bud removal and pruning.

[0073] Bud removal and pruning: In the first three years, bud removal is carried out once at the end of the first year of cultivation. In the second and third years, bud removal and pruning are carried out once in spring and autumn and winter respectively.

[0074] Pruning: Pruning is carried out every 1-2 years from the 4th to the 7th year. In the 7th year, the trunk of the target tree is obvious, and the forest canopy density reaches a level that inhibits the germination of lateral buds, laying a good foundation for the cultivation of large-diameter knot-free timber in the later stage.

[0075] S3. Pest and disease control: After the loblolly trees are planted, they should be monitored for pests and diseases and controlled in a timely manner.

[0076] In this embodiment, in S1, uniform thinning and planting density: the canopy density after uniform thinning is controlled at 0.5-0.6, and the planting density is recommended to be 3-4m×4m, that is, 50 plants per mu; block thinning and planting density: the thinning area is controlled at 400m 2 The recommended planting density is 3m×3-4m, that is, 65 plants per mu.

[0077] In this embodiment, in S1, mixed forest with fast-growing tree species: fast-growing tree species include eucalyptus, birch and acacia sempervirens. These tree species grow fast in the early stage and can quickly form a forest stand environment. In the later stage, fast-growing tree species are in the upper layer. The branches and leaves of the tree species are relatively sparse and the light transmittance is high, which is conducive to forming a forest stand environment suitable for the development of eucalyptus species. The planting density is recommended to be 2-3m×3m, that is, 74-111 plants per mu; mixed mode 1: row mixed, 3 rows of fast-growing tree species: 1 row of eucalyptus, eucalyptus accounts for 30%; mixed mode 2: block mixed eucalyptus planting block area 250m 2 , the block spacing is greater than 20m, and the area of ​​​​eucalyptus planting accounts for 30% of the afforestation land.

[0078] In this embodiment, in S2, afforestation includes digging holes according to specifications, and the hole specifications are 45 cm long × 45 cm wide × 35 cm deep. The afforestation time is the early spring rainy season, and afforestation can also be carried out in the winter rainy season if conditions permit.

[0079] In this embodiment, fertilization is specifically as follows: base fertilizer is applied according to soil fertility, with a ratio of 1 kg of organic fertilizer, 0.6 kg of calcium magnesium phosphate fertilizer, and 0.4 kg of compound fertilizer;

[0080] Strip weeding is carried out once in April-June and September-November each year, with a forest belt width of 1m, followed by topdressing;

[0081] According to the development characteristics of the forest and the need to save fertilizer, the amount of topdressing is 70g of compound fertilizer in the first year; in the spring of the second and third years, topdressing is urea, 130g and 170g respectively; in the autumn of the second and third years, topdressing is compound fertilizer, with the amounts of 170g and 230g respectively.

[0082] In this embodiment, in S3, according to the site and forest stand growth conditions, a 6-8 meter section without side branches is eventually formed. After the forest belt is cleared, bud removal and pruning are carried out. The new buds on the side branches are broken off by hand before they are lignified. At this time, the branch epidermis is white-green, partially red, and the leaves are not unfolded. When they are unfolded, the semi-lignified and lignified branches with bright green epidermis and brown base cannot be bud-removed and need to be cut off with a knife or pruned with branch shears / high branch shears. Callus cream needs to be applied to incisions larger than 2 cm, and pruning should be carried out before the diameter of the branch base reaches 1.5 cm.

[0083] In this embodiment, in S4, the main disease of the seedling stage of the loblolly tree is damping-off disease, and the prevention and control method is: before sowing, the soil is disinfected by pouring 40% formalin 2.5g / L solution.

[0084] In this embodiment, in S4, the main insect pests are stem borers, and the method for preventing and controlling stem borers can be sprayed with 1g / L of dimethoate solution once a week for 4 consecutive times.

[0085] In this embodiment, in S2, the afforestation land is selected to be acidic sandy loam or light clay with a thick soil layer below 600m above sea level, and is grown in dense forests or sparse forests in mountains.

[0086] In this embodiment, in S2, before planting, the seeds of the Euphorbia obesa are placed in boiling water at 90°C and stirred until the water temperature drops to a suitable level, or soaked in concentrated sulfuric acid for 10 minutes, and then the colloid on the surface of the seeds is washed off with clean water. Next, the treated seeds are soaked in clean water for 12 hours.

[0087] Embodiment 3

[0088] A technique for cultivating knot-free wood of euphorbia pulcherrima, comprising the following steps:

[0089] S1. Environmental regulation in the early stage of afforestation:

[0090] Environmental control: uniform thinning and mixed planting of uneven ages, block thinning and mixed planting of uneven ages;

[0091] Selection of companion tree species: Mix with fast-growing tree species of the same age;

[0092] S2, Young forest cultivation and management stage:

[0093] Afforestation and tending management: The first three years after afforestation are the afforestation and tending management period. The main technologies include afforestation density, tending, fertilization, and bud removal and pruning.

[0094] Bud removal and pruning: In the first three years, bud removal is carried out once at the end of the first year of cultivation. In the second and third years, bud removal and pruning are carried out once in spring and autumn and winter respectively.

[0095] Pruning: Pruning is carried out every 1-2 years from the 4th to the 7th year. In the 7th year, the trunk of the target tree is obvious, and the forest canopy density reaches a level that inhibits the germination of lateral buds, laying a good foundation for the cultivation of large-diameter knot-free timber in the later stage.

[0096] S3. Pest and disease control: After the loblolly trees are planted, they should be monitored for pests and diseases and controlled in a timely manner.

[0097] In this embodiment, in S1, uniform thinning and planting density: the canopy density after uniform thinning is controlled at 0.5-0.6, and the planting density is recommended to be 4m×4m, that is, 56 plants per mu; block thinning and planting density: the thinning area is controlled at 500m 2 The recommended planting density is 3m×4m, that is, 74 plants per mu.

[0098] In this embodiment, in S1, mixed forest with fast-growing tree species: fast-growing tree species include eucalyptus, birch and acacia sempervirens. These tree species grow fast in the early stage and can quickly form a forest stand environment. In the later stage, fast-growing tree species are in the upper layer. The branches and leaves of the tree species are relatively sparse and the light transmittance is high, which is conducive to forming a forest stand environment suitable for the development of eucalyptus species. The planting density is recommended to be 2-3m×3m, that is, 74-111 plants per mu; mixed mode 1: row mixed, 4 rows of fast-growing tree species: 1 row of eucalyptus, eucalyptus accounts for 40%; mixed mode 2: block mixed eucalyptus planting area 400m 2 The block spacing is greater than 20m, and the area of ​​​​eucalyptus planting accounts for 40% of the afforestation land.

[0099] In this embodiment, in S2, afforestation includes digging holes according to specifications, and the hole specifications are 40-50 cm long × 40-50 cm wide × 30-40 cm deep. The afforestation time is the early spring rainy season, and afforestation can also be carried out in the winter rainy season if conditions permit.

[0100] In this embodiment, fertilization is specifically as follows: base fertilizer is applied according to soil fertility, with a ratio of 1.5 kg of organic fertilizer, 0.75 kg of calcium magnesium phosphate fertilizer, and 0.5 kg of compound fertilizer;

[0101] Strip weeding is carried out once in April-June and September-November each year, with a forest belt width of 0.8-1.2m, followed by topdressing;

[0102] According to the development characteristics of the forest and the need to save fertilizer, the amount of topdressing is 100g of compound fertilizer in the first year; in the spring of the second and third years, topdressing is urea, 150g and 200g respectively; in the autumn of the second and third years, topdressing is compound fertilizer, with the amount of 200g and 250g respectively.

[0103] In this embodiment, in S3, according to the site and forest stand growth conditions, a 6-8 meter section without side branches is eventually formed. After the forest belt is cleared, bud removal and pruning are carried out. The new buds on the side branches are broken off by hand before they are lignified. At this time, the branch epidermis is white-green, partially red, and the leaves are not unfolded. When they are unfolded, the semi-lignified and lignified branches with bright green epidermis and brown base cannot be bud-removed and need to be cut off with a knife or pruned with branch shears / high branch shears. Callus cream needs to be applied to incisions larger than 2 cm, and pruning should be carried out before the diameter of the branch base reaches 1.5 cm.

[0104] In this embodiment, in S4, the main disease of the seedling stage of the loblolly tree is damping-off disease, and the prevention and control method is: before sowing, the soil is disinfected by pouring 40% formalin 2.5g / L solution.

[0105] In this embodiment, in S4, the main insect pests are stem borers, and the method for preventing and controlling stem borers can be sprayed with 1g / L of dimethoate solution once a week for 4 consecutive times.

[0106] In this embodiment, in S2, the afforestation land is selected to be acidic sandy loam or light clay with a thick soil layer below 600m above sea level, and is grown in dense forests or sparse forests in mountains.

[0107] In this embodiment, in S2, before planting, the seeds of the Euphorbia obesa are placed in boiling water at 100°C and stirred until the water temperature drops to a suitable level, or soaked in concentrated sulfuric acid for 10 minutes, and then the colloid on the surface of the seeds is washed off with clean water. Next, the treated seeds are soaked in clean water for 12 hours.

[0108] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A technique for cultivating knot-free wood of Euphorbia cerasifera, characterized in that: The following steps are involved: S1. Environmental regulation in the early stage of afforestation: Environmental control: uniform thinning and mixed planting of uneven ages, block thinning and mixed planting of uneven ages; Selection of companion tree species: Mix with fast-growing tree species of the same age; S2, Young forest cultivation and management stage: Afforestation and tending management: The first three years after afforestation are the afforestation and tending management period. The main technologies include afforestation density, tending, fertilization, and bud removal and pruning. Bud removal and pruning: In the first three years, bud removal is carried out once at the end of the first year of cultivation. In the second and third years, bud removal and pruning are carried out once in spring and autumn and winter respectively. Pruning: Pruning is carried out every 1-2 years from the 4th to the 7th year. In the 7th year, the trunk of the target tree is obvious, and the forest canopy density reaches a level that inhibits the germination of lateral buds, laying a good foundation for the cultivation of large-diameter knot-free timber in the later stage. S3. Pest and disease control: After the loblolly trees are planted, they should be monitored for pests and diseases and controlled in a timely manner.

2. The knot-free wood cultivation technology of the loblolly wood according to claim 1, characterized in that: In S1, uniform thinning: the canopy density after uniform thinning is controlled at 0.5-0.6, and the planting density is 3-4m×4m, that is, 42-56 plants per mu; block thinning: the thinning area is controlled at 300-500m 2 The planting density is 3m×3-4m, that is, 56-74 plants per mu.

3. The knot-free wood cultivation technology of the loblolly wood according to claim 2, characterized in that: In S1, mixed forest with fast-growing tree species: fast-growing tree species include eucalyptus, birch and acacia sempervirens, with a planting density of 2-3m×3m, i.e. 74-111 trees per mu; mixed planting method 1: row mixed planting, 2-4 rows of fast-growing tree species: 1 row of eucalyptus, eucalyptus accounts for 20-40%; mixed planting method 2: block mixed planting of eucalyptus, the area of ​​the block is 100-400m 2 , the block spacing is greater than 20m, and the area of ​​​​eucalyptus planting accounts for 20-40% of the afforestation land.

4. The knot-free wood cultivation technology of the loblolly wood according to claim 3, characterized in that: In S2, afforestation includes digging holes according to specifications, and the hole specifications are 40-50 cm long×40-50 cm wide×30-40 cm deep. The afforestation time is the early spring rainy season, and afforestation can also be carried out in the winter rainy season if conditions permit.

5. The knot-free wood cultivation technology of the loblolly wood according to claim 4, characterized in that: The fertilization is specifically as follows: applying base fertilizer according to soil fertility, with a ratio of 0.5-1.5kg of organic fertilizer, 0.5-0.75kg of calcium magnesium phosphate fertilizer, and 0.25-0.5kg of compound fertilizer; Strip weeding is carried out once in April-June and September-November each year, with a forest belt width of 0.8-1.2m, followed by topdressing; According to the development characteristics of the trees and the need to save fertilizer, the amount of topdressing is 50-100g of compound fertilizer in the first year; in the spring of the second and third years, topdressing is urea, 100-150g and 150-200g respectively; in the autumn of the second and third years, topdressing is compound fertilizer, with the amount of 150-200g and 200-250g respectively.

6. The knot-free wood cultivation technology of the loblolly wood according to claim 5, characterized in that: In the S2, according to the site and forest growth conditions, a 6-8 meter section without side branches is eventually formed. After the forest belt is cleared, bud removal and pruning are carried out. The new buds on the side branches are broken off by hand before they are lignified. At this time, the branch epidermis is white-green, partially red, and the leaves are not unfolded. When they are unfolded, the semi-lignified and lignified branches with bright green epidermis and brown base cannot be bud-removed and need to be cut off with a knife or pruned with branch shears / high branch shears. Callus cream needs to be applied to incisions larger than 2 cm, and pruning is carried out before the diameter of the branch base reaches 1.5 cm.

7. The knot-free wood cultivation technology of the loblolly wood according to claim 6, characterized in that: In S3, the main disease of the seedling stage of the loblolly tree is damping-off disease, and the prevention and control method is: before sowing, the soil is disinfected by watering with 40% formalin 2.5g / L solution.

8. The knot-free wood cultivation technology of the loblolly wood according to claim 7, characterized in that: In the S3, the main insect pests are the stem borers. The method for preventing and controlling the stem borers can be to spray 1g / L of dimethoate solution once a week for 4 consecutive times.

9. The knot-free wood cultivation technology of the loblolly wood according to claim 8, characterized in that: In the above S2, the afforestation land is selected to be acidic sandy loam or light clay with a thick soil layer below 600m above sea level, and grows in dense forests or sparse forests in mountains.

10. The knot-free wood cultivation technology of the loblolly wood according to claim 9, characterized in that: In S2, before planting, the seeds of the Euphorbia obesa are placed in boiling water at 80-100°C and stirred until the water temperature drops to a suitable level, or soaked in concentrated sulfuric acid for 10 minutes, and then the colloid on the surface of the seeds is washed off with clean water, and then the treated seeds are soaked in clean water for 12 hours.

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