Koelreuteria paniculata, aliases: luan, luanhua, etc., is a subfamily, luan tree plant. It is a deciduous tree or shrub; the bark is thick, gray-brown to gray-black, longitudinally lobed in old age; the skin hole is small, gray to dark brown; the small branches have warts, and the leaf shaft and petiole are wrinkled short soft hairs or hairless.
Luan trees have few diseases and insect pests, easy cultivation management, and the cultivation soil is most suitable for deep, moist soil. Mainly sowing and propagation, tillers or root cuttings can also be made, and the main root and thick lateral roots are appropriately cut when transplanting, which can promote multiple whisker roots and make it easy to survive. Harvested when the autumn fruit is ripe, it is dried and shelled in time. Because the seed coat is hard and impermeable, if not treated, the second year of spring sowing often does not germinate, so the autumn shelling sowing, can be wet sand layer treatment after spring sowing. Generally using ridge sowing, the distance is 60-70cm, because the seed emergence rate is low, so the amount of seeds is large, and the sowing amount is 30-40kg/mu.
<h3>Propagation and sowing</h3>
Seed propagation
Luan tree
The fruit of the luan tree ripens from September to October. Select a good growing, dry and straight, open canopy, full fruit, in the prime of the excellent single plant as the mother tree, in the fruit is reddish brown or orange and the capsule has not yet cracked when the collection in time, otherwise it will fall off on its own. However, it should not be picked too early, otherwise the seed germination rate is low.
After the fruit is collected, the peel and stem of the fruit are removed, and the dried or dried should be dried in time, and after the capsule is cracked, it is beaten and threshed, and the seed is purified by the screening method. The seeds are black, spherical, about 0.6cm in diameter, about 20% seeding rate, about 150g in 1,000 grains, and a germination rate of 60% to 80%.
The seed coat of Luan tree seeds is hard and impermeable, and if it is not managed by germination, it is often sown in the spring of the following year without germination or the germination rate is very low. Therefore, sowing in the autumn of that year and letting the seeds complete the germination stage in the soil can eliminate the process of seed storage and germination. After a winter, in the spring of the second year, the seedlings emerge early and neatly, and grow robustly.
In late autumn, choose high and dry terrain, good drainage, leeward and sunny digging pits. The pit is 1 to 1.5 m wide, deep above the groundwater table, below the permafrost, about 1 m, and the length of the pit depends on the number of seeds. The bottom of the pit can be laid with a layer of gravel or coarse sand, about 10 to 20 cm thick, and a bunch of grass handles are inserted in the pit for ventilation. The sterilized seeds are mixed with wet sand and placed in the pit, and the seed and sand volume ratio is 1:3 or 1:5, or 1 layer of seeds and 1 layer of sand are staggered. The thickness of each layer is about 5cm. The humidity of the sand is suitable for the hand to be able to hold the ball, do not come out of the water, and let go of the hand to spread out. Install until it is about 20 cm above the ground, cover it with 5 cm of river sand and 10 to 20 cm thick straw, etc., and dig a drainage ditch around it.
Luan trees generally use field seedlings. Sowing land requires that the soil be loose and breathable, the land preparation should be flat and fine, and for arid and rainy areas, it is advisable to irrigate the bottom water before sowing. The germination rate of luan tree seeds is low, and the amount of seeds used should be large, generally 50 to 100 grams per square meter.
Sow in the spring in March, take out the seeds and sow them directly. Apply basal fertilizer on selected plots, sprinkle furandan granules or zinc thiophos granules 3000 g per acre to 4000 g for insecticide. The use of wide strip sowing is not only conducive to the ventilation and light transmission of seedlings, but also easy to manage. Dry-hidden seeds are sown in broad strips about 45 days before sowing. After sowing, cover a layer of loose and fine crushed soil 1 to 2 cm thick to prevent the seeds from drying and losing water or being endangered by birds and animals. Immediately watered once with small water, and then covered with grass, straw and other materials to increase the ground temperature, maintain soil moisture, prevent weeds from growing and soil compaction, about 20 days after the seedlings are ready, remove the straw.
Cuttings and seedlings
Collection of cuttings: After the leaves fall from the trees in autumn, combined with the flat stubble of l annual seedlings, the trunks with a base diameter of 0.5 to 2 cm are collected as seed strips, or the tillers of the year of perennial luan trees are collected, and the long branches are used as seed strips, and bundled while collecting. Immediately after tidying up, bury it in wet soil or wet sand so that it does not lose moisture for cuttings.
Cutting of cuttings: take out the buried cuttings, cut them into small segments of about 15cm, cut flat on the upper shear, 1.5cm from the bud, cut the lower shear close to the bud, and cut the lower shear obliquely.
Winter storage of cuttings: The winter storage site should be selected in the shade of the back that is not easy to accumulate water, the depth of the ditch is about 80cm, and the width and length of the ditch depend on the cuttings. Lay a layer of wet sand about 2 to 3 cm deep at the bottom of the ditch and place the cuttings vertically in the sand ditch. Pay attention to the upward direction of the leaf buds, place them in a single layer, and then cover them with wet sand 50 to 60 cm thick.
Cuttings: Soil cuttings are made of loam soil with rich humus, loose soil, aeration and good water retention, and organic fertilizer is applied. The soil is prepared in autumn, deep ploughing, leveling and fine, and cuttings are cut in the spring of the following year. The row spacing is 30 cm×50 cm, first punch the hole with a wooden stick, insert it straight, and expose 1 to 2 buds in the cuttings.
Post-planting management: maintain soil moisture, appropriately build shade shelters and apply nitrogen and phosphorus fertilizers, carry out appropriate irrigation and topdressing, and control water and fertilizer during the hardening period of seedlings to promote lignification.
Shaping trimming
1. Select the main branches After the Luan tree is dried, 3-5 strong and evenly distributed main branches are selected in the winter of that year or the spring of the following year, and the remaining branches are cut off.
2, the selection of side branches In order to promote the growth of the main technology of selection, in the summer, it is necessary to cut the new shoots that sprout on the main branches in time. The first time to peel the buds, each main branch to leave 3-5 buds, the second time to leave 2-3, the direction of the buds should be reasonable, the distribution should be uniform.
3. In the winter, the branches are shortened, so that the side branches on each main branch are evenly distributed and the direction is reasonable. Cut 2-3 side branches, the rest are all cut off, and the length of the stub is about 60 cm. This is shortened for 3 years, the canopy expands, and the trunk is thick, forming a spherical canopy.
4. Winter disease, dry and weak branches Every winter, cut off dry dead branches, diseased and insect branches, intersecting branches, thin weak branches, and dense branches. If the extension of the main branch is too long, it should be retracted in time to prune and continue to be the extension head of the main branch. For the erect branches on the back of the main branch, cut off from the base. Retain some small side branches on both sides of the main branch, so that there is space, but it does not disturb the tree shape and does not affect the growth of the main branch.
Note that the large branches of the overly stout luan tree should be cut in sections to prevent splitting the main pole. Because of the influence of the direction of the road, the ground building and the underground pipe network, it often causes the phenomenon of partial crown and tilt during the growth of luan trees, and the shape should be trimmed as soon as possible to adjust the center of gravity. For trees with weak growth potential, as long as they do not affect overhead lines or buildings, they should not be cut or cut lightly to achieve the purpose of alleviating the tree momentum and balancing growth. Pruning luan trees should comply with safe operating practices to prevent accidents. Also pay attention to the safety of pedestrians and nearby buildings. [1]
<h3>Field management</h3>
Luan tree planting management
(1) Shade: The shade time and shade degree should be determined by the local temperature and climatic conditions at that time to ensure that its seedlings are not harmed by sunburn. In the autumn, the light time and light intensity should be gradually extended until full light is received to increase the degree of lignification of the seedlings.
(2) Inter-seedlings, supplementary seedlings: when the seedlings grow to a height of 5 to 10 cm, the seedlings should be interspersed, and the seedlings between the plants should be combined with watering and fertilization after the seedlings were separated, leaving about 12 seedlings per square meter. The inter-seedling requires that the small and large, the inferior remain the superior, the inter-dense remain thin, the whole seedling is equidistant, and it is better to carry out on rainy days. Combined with inter-seedlings, the missing plants are treated to ensure that the seedlings are evenly distributed.
(3) Daily management: to often loosen the soil, weeding, watering, keep the bed surface moist, most of the seedlings can be as high as 2m after the fall of leaves in late autumn, and the diameter of the ground is about 2cm. The seedlings are dug up and graded, transplanted in the spring of the following year, the roots are slightly shortened before transplantation, and the dried seedlings are cut off from the rhizome after transplantation, that is, the stubble is flattened from the surface, and then watered. After germination, the buds should be wiped frequently, leaving only the strongest bud to cultivate into the trunk. During the growth period, the soil is loosened, hoeed, watered, and fertilized, and a straight trunk can be formed in the autumn.
(4) Transplantation: Seedling transplanting can promote the development of the root system of seedlings, and the annual seedlings are 50 to 70 cm tall. Luan tree is a deep-rooted tree species, which should be transplanted multiple times to form a good and effective root system. The sown seedlings can be dug into the ditch after the leaves fall in the autumn of that year, and are planted in the spring of the following year.
Since the trunk of the luan tree is not easy to grow straight, the first transplant should be dried with stubble and strengthen the management of fertilizer and water. In the spring, the branches are sprouted from the base, and the straight, robust people are selected to cultivate into the main trunk, and the main trunk grows rapidly and straight. If the first drying does not meet the requirements, the second spring can be dried again. After that, transplantation should be carried out every 3 years or so, and the main root and the thick lateral root should be cut properly during transplantation to promote the development of new roots. The young trees of Luan trees grow slowly, and the first two transplants should be properly densely planted, which is conducive to cultivating a straight trunk and saving land. Thereafter, the canopy should be properly sparse and well cultivated.
(5) Fertilization: Fertilization is an important measure to cultivate strong seedlings. After the seedlings are excavated and the roots are long, they should be combined with watering and fertilization. During the peak annual growth period, a fast-acting fertilizer based on nitrogen should be applied to promote the vegetative growth of plants. In autumn, it is necessary to stop applying nitrogen fertilizer and increase the application of phosphorus and potassium fertilizers to improve the degree of lignification of plants and improve the cold resistance of seedlings. In winter, it is advisable to apply farmhouse organic fertilizer as a base fertilizer, which not only provides effective nutrients for the growth of seedlings, but also plays a role in heat preservation and soil improvement. With the growth of seedlings, the amount of fertilization should be gradually increased to meet the nutrient requirements of seedling growth. The amount of fertilizer for the first time should be less, 2500g to 3000g of nitrogen fertilizer per mu, and then applied once every 15 days, and the fertilizer amount can be slightly larger.
<h3>Transplanting</h3>
Large seedling cultivation generally when the trunk height reaches the height of the branching point, the main branch is left, and it can be released in 3 to 4 years. If the annual seedlings are not straight or do not meet the fixed dry standards, they shall be re-cultivated after the stubble is flattened the following year. Generally, after two transplants, culture for 3 to 6 years, the chest diameter can reach 4 to 8 cm.
Colonization density: about 600 trees per mu with a chest diameter of 4 to 5 cm, 200 to 300 trees per mu with a chest diameter of 6 to 8 cm, select 3 to 5 main branches, short as 40 cm, each main branch leaves 2 to 3 side branches, and the crown height ratio is 1:3.
Cultivate full-crown seedlings with a dry diameter of 8 to 12 cm, plant 160 to 170 plants per mu, that is, the plant row spacing is 2 m×2 m; cultivate large seedlings with a dry diameter of more than 12 cm, plant 130 plants per mu, that is, the plant row spacing is 2 m×2.5 m. In combination with nursery management, prune budding branches with a dry height of less than 1.5 m to promote straight growth of the main trunk.
Seedling shaping and pruning luan tree crown is nearly spherical in shape, generally using a natural tree shape. The plastic surgery requirements vary depending on the use. The seedlings used in the street tree require the trunk to be straight, the height of the first branch is 2.5 to 3.5 m, the canopy is complete and full, and the branches are evenly distributed and unfolded. Shade trees require a large and dense canopy, with the first branch being lower in height than the street tree. During the incubation process, corresponding pruning measures should be taken around the above requirements. This can generally be done in winter or during transplantation.
<h3>disease control</h3>
Luan tree flow gum disease
Gum disease: This disease occurs mainly in the trunk and main branches, but can also occur on the branches. At the beginning of the disease, the diseased part is slightly swollen, dark brown, the surface is moist, and the posterior part of the disease is dented and cracked, spilling a pale yellow translucent soft rubber block, and finally becoming an amber-like hard rubber block, with a smooth and shiny surface. Trees grow weakly, and when severe, they can cause some branches to dry out.
Prevention and control measures:
(1) Scratch scar coating medicine. Scrape the gel from the branches with a blade and then apply the wound with carding agent and agent.
(2) Strengthen management, pay attention to cold protection and antifreeze in winter, and can be applied white or carding agent. In summer, pay attention to preventing sunburn, timely control of branch diseases and insect pests, and try to avoid mechanical damage.
(3) Spray the stone sulfur compound before the early spring germination, spray once every 10 days, and spray twice in a row to kill the overwintering bacteria. Spray 800 to 1000 times of bacillus or carbendazim during the onset period.
Luan tree aphid disease
Aphid disease: Luan tree aphids are the same as the order, aphid family, is a major pest of luan tree, mainly harm the young shoots, shoots, young leaves of luan trees, when serious, young branches are covered with insect bodies, affecting the growth of branches, causing the tree to weaken, and even death.
Prevention and control methods:
(1) Spray aphid net 2000 times liquid, 40% oxidized Lego emulsion, aphid pine emulsion or imidacloprid agents during the initial incubation period of aphids.
(2) Cut off the germinated branches on the trunk with serious insect pests in time at the initial stage to eliminate the aphids that have not yet spread at the beginning.
(3) Pay attention to the protection and utilization of natural enemies such as ladybirds and grasshoppers.
(4) Young trees can be buried in the root in late April, 15% of the nodal granules, the trunk diameter of the tree per centimeter of medicine 1 ~ 2g, after covering the soil watering; or watering of le fruit emulsion, dry diameter per centimeter of pouring watering about 1.5kg.
1. For trees with a large number of winter insect eggs, spray 30 times the No. 20 petroleum emulsion before the trees germinate in early spring. Spraying aphid net 2,000 times liquid or 10% imidacloprid 2,000 times solution or 10% imidacloprid 2,000 times solution began in early April during the initial incubation period of aphids.
Luan tree six-star black-spotted leopard beetle moth
2. Cut off the germinating branches on the trunk in time at the initial stage, and eliminate the aphids that have not yet spread at the beginning. Pay attention to the protection and use of natural enemies such as ladybirds and grasshoppers.
Six-star black-spotted leopard beetle moth: annual generation, overwintering as larvae. The overwintering larvae begin to active in early April, pupate in mid-May, the adults feather and lay eggs in early June, and the larvae hatch in late June. The larvae can be mothed into the branches from the base of the petiole, the posterior part of the main vein of the leaf, or directly into the branches, and are withered by the front ends of the moth branches. The larvae can be transferred to pests or turn around in the worm tunnel, and in October the larvae moth into the biennial branches to overwinter. The insect discharges a large amount of granular wood chips when it is damaged by moths. A large number of dead branches appeared in the affected plants in August and September, which seriously damaged the landscape.
The most effective control method is to manually cut off the branches with insects and dead branches. It can also be sprayed with contact killers during the incubation period of larval hatching moths, such as 1000 times liquid for insect killing, or with endosorbent agents such as imidacloprid 2000 times liquid.
Peach-necked celestial bull: mainly harmful to xylem.
Peach-necked celestial bull
The eggs are mostly laid in the crevices of the bark of the weak branches of the tree, and the larvae hatch and feed down on the phloem. After the larvae regain their activity the following spring, they continue to feed downward from the cortex to the xylem surface, initially forming a short oval moth tunnel with a depression in the middle. After June, it is mothed into xylem from the middle of the moth road, and the moth road is irregular. The larvae then feed from top to bottom and moth into curved, irregular holes in the trunk, some up to 50 cm long. On closer inspection, there are often a large number of excreted reddish-brown feces debris outside the borer holes in the trunk and on the ground. The effect of drying with a medicated agent to prevent and control the peach red necked celestial cow is better, and an assorptive insecticide can be selected.
Jujube turtle wax suke: Ceroplastes japonicus Gr belongs to the order Homoptera, wax suke, also known as Japanese wax suke, jujube bag wax suke, commonly known as jujube lice. When it occurs in a large area of Luan trees, the whole branch and leaf are covered with insect bodies, and the female insects attached to the branches look like snow from a distance, and the nymphs suck sap on the leaves, and the excrement is scattered all over the tree, causing the tree to weaken and seriously affecting the green landscape. Through two years of investigation and research, the occurrence of the insect was found out and a satisfactory control method was found.
Luan Tree Japanese Turtle Wax Suke
1． Artificial control: From November to March of the following year, the overwintering female adults can be scraped off, and the branches can be pruned with pruning.
2． Hit the ice edge to eliminate the overwintering female adults, in the harsh winter season, if there is rain and snow weather, when there is thick ice on the branches, timely knock on the branches to shake off the ice, the wintering insects can be shaken down with the ice.
3． Spray 40% oxylgo + 40% hydroamine thiophos 1000 to 1500 times during the large occurrence of nymphs, sprayed 2 to 3 times, at intervals of 7 to 10 days.
4． Furandan root irrigation: Irrigated with 25% wettable powder 200 to 300 times in May, the effect is very good at killing nymphs.
Japanese Turtle Wax Suke: Control Measures:
1. During the nymph outbreak period, spray lesben 2000 times and washing powder 1000 times mixed solution, spray 2 to 3 times, interval 7 to 10 days. Irrigating the roots 2 times in May with 25% furandan wettable powder 200 to 300 times is very effective in killing nymphs.
2. From November to March of the following year, the overwintering female adults can be scraped off, and the insect body can be scraped down to the plastic bag and buried deeply, and the pruning can be combined to cut off the insect branches. Hit the ice edge to eliminate the overwintering female adults.
Double-toothed long beetle: occurrence law: double-toothed long beetle is a kind of borer pest that is more seriously harmful to garden trees, with adults and larvae endangering the branching position of trees, hatching larvae along the branches longitudinally moth to eat the primary xylem, with the increase of age gradually moth to eat heartwood, adult moths into the branches after close to the phloem annular feeding week to form a circular pit, and there is a repetitive feeding habit. Adults and larvae eat tree branches, the initial appearance of the hazard is not obviously damaged, in the autumn and winter when the wind comes, the new branches of the victim are blown off by the wind from the circular moth, the next year the side shoots are overgrown, so repeatedly, the canopy is easy to become broom-shaped, affecting the growth and form of the tree; in the summer and autumn, causing the young tree trunk to die, the large branches withered or wind broken, posing a serious threat to the urban landscaping.
1. Strengthen quarantine: Strengthen the quarantine of seedlings, strictly prevent death, and prevent the spread and spread of double-toothed beetles. The main quarantine measures include quarantine at the place of origin, quarantine for transfer and transportation, and re-inspection.
2, prevention: double-toothed long beetle body is small, the borer hole is hidden, all insect states are hidden life, not easy to be found, the main harm to seedlings and branches, not harmful to fruits and leaves, comprehensive prevention and control measures should be taken.
3. Physical prevention and control:
(1) Clean up dead branches and damaged trees and suppress the source of insects.
(2) Adult worms have the habit of going out during the spawning stage and the adult feathering stage, and adult insects are artificially captured.
4. Biological control: Guan's swollen-legged bee can parasitize the larvae and pupae of the double-toothed long-legged beetle, and the control rate can reach 40 to 50% in mid-to-late May.
5. Pharmaceutical prevention and treatment:
(1) Spraying: from late March to mid-to-late April, adult worms go out to mate and adult worms go out to activity from late June to early August, spray 20% rapid killing 3000 times liquid or 12% nicotinine emulsion 1000 times liquid, etc. Because the adults go out untidy, it is necessary to choose a long-acting agent.
(2) Blocking the worm hole: use 20% chrysanthemum milk oil 800 times liquid, and then add wood chips to mix into a paste, make a poison, and block the borer hole of the double-toothed long beetle from mid-to-late April to the first sentence in October.
Powdery mildew: control measures:
1. Agricultural measures are first, planting disease-resistant varieties; second, reasonable dense planting and reasonable fertilization.
2. Pharmaceutical prevention and control: one is the plot where the autumn seedlings have a serious disease, which can be mixed with seeds, and the method is the same as that of wheat smut; the second is in the autumn or spring, when the field incidence is 3% to 5% (the adult plant period investigation is calculated by the flag leaf to the 2 leaves under the flag leaf), every 666.7 square meters with 20 to 30 ml or 15% powder rust nin wettable powder 50 grams, 50 to 60 kg spray to water, or 10 to 15 kg of low-volume spray to water. It can also be used with 25% zebrain emulsion per 666.7 square meters 50 ml, add 50 kg of water, spray evenly.
In addition, the mulberry thorn ruler moth, the luan tree jujube turtle wax introduction, and the national locust small line horn wood beetle moth will also cause harm to the luan tree, and it is necessary to strengthen prevention. [2]
<h3>Resources</h3>
1. Trimming of Luan Trees on Sidewalk Trees [Cited on 2020-05-19]
2. Luan Tree - Luan Tree Pictures, Ornamental Value and Garden Use of Luan Tree, Luan Tree Pruning Cultivation Maintenance Management| Garden Plants [Cited on 2020-07-28]
This article was edited by headline encyclopedia users Happy 1978, Beichen 82660108, and Autumn Love Tomorrow.