synonymPoplar tree(Populus alba of Salicaceae) generally refers to Populus alba
White poplar（Populus alba50. ) is SalicaceaePopulusTrees and plants.[6]The crown of the white poplar is wide oval or spherical, and its bark is gray white and smooth. When it is old, it is deeply split, and its young branches, leaves and buds are densely covered with white hairs;The long branches and leaves are broadly ovate or triangular ovate, and the leaf base is truncate or nearly heart-shaped;The leaves of the short branches are smaller, ovate or elliptic ovate;The petiole is slightly flat, without glands, and the back of the old leaf and petiole are densely covered with white hairs. The flowering period is from March to April, and the fruit period is from April to May.[7]
White poplar is produced in Xinjiang, China, and cultivated in southern Liaoning, Ningxia and western Tibet.[8]Silver white Yang Xiguang is cold resistant, drought resistant, light saline alkali resistant, not shade resistant, not damp heat resistant, strong wind resistance, disease resistance and insect pest resistance.The propagation mode of Populus alba is to bury strips and root tillers.[9]
Anhui Traditional Chinese Medicine: "cough relieves asthma, clearing heat and resolving phlegm".[10]The wood of white poplar has straight grain, fine structure, light and soft quality, and can be used for building, furniture, paper making, etc;Bark can be used to make tannin extract;Grinding leaves can drive away bedbugs;The tree is tall with beautiful branches and leaves, and the young leaves are red, which can be used as greening trees.[8]The silver white poplar is still large, and its silver white leaves are swaying in the breeze. Under the sun, it has a unique relaxing effect. It can be used as a shade tree, street tree, or isolated or clustered on the lawn.[7]
Branches:Young branches of white poplar are covered with white hairs, and sprout strips are densely covered with hairs;Buds densely covered with white villi, falling off later;The sprouting branches and long branches and leaves are ovoid, palmately 3-5 lobed, 4-10 cm long, the apex of the lobes is blunt, the base is wide cuneate, round, flat or nearly heart-shaped, the edges of the lobes are irregularly concave, and the first two surfaces are covered with white hairs, and then the upper surface falls off;The short branches and leaves are 4-8 cm long, oval or oval oval, with wide cuneiform and round base, slightly heart-shaped or flat cut, irregular blunt teeth, smooth above and white down below;Petiole shorter than or equal to leaf blade, slightly laterally compressed, white tomentose.
Leaf:The sprout branches and long branches of white poplar are ovoid, palmately 3-5 lobed, 4-10 cm long, the tip of the lobes is blunt and pointed, the base is wide cuneate, round, flat cut or nearly heart-shaped, the edges of the lobes are irregular concave, and the first two sides are covered with white hairs, and then the upper part falls off;The short branches and leaves are 4-8 cm long, oval or oval oval, with wide cuneiform and round base, slightly heart-shaped or flat cut, irregular blunt teeth, smooth above and white down below;Petiole shorter than or equal to leaf blade, slightly laterally compressed, white tomentose;
FLOWER:The male inflorescence of white poplar is 3-6 cm long, the inflorescence axis is hairy, and the bracts are membranous, wide elliptic, about 3 mm long, with irregular teeth and long hairs on the edge;Disk has short stem, wide elliptic, oblique;Stamens 8-10;The female inflorescence is 5-10cm long, the inflorescence axis is hairy, the pistil has a short stalk, the style is short, the stigma is 2, and there are long yellowish lobes.
Fruit:The white poplar is a thin conical capsule, about 5 mm long, 2-valved, glabrous.[12]
White Poplar (original variety) Plate 1:1-4
Growth environment
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White poplar likes continental climate, light, cold resistance, and no freezing damage at - 40 ℃.Not shade tolerant, deep rooted.It is strong in wind resistance and drought resistance, but it is not resistant to humidity and heat. Most of the plants planted in the south of Beijing are affected by diseases and pests.
Distribution range
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White poplar is produced in Xinjiang, China, and cultivated in southern Liaoning, Ningxia and western Tibet.[8]
Main varieties
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1. White poplar (variety)
White poplar
Latin name:Populusalbavar.bachofenii（Wierzb.） Wesm.
The bark is gray or greenish gray, smooth;The tree crown is broad and the branches are spreading.The sprouts and long branches and leaves are palmately 3-5 deep fissured, the base is truncated, the middle lobes are mostly 2-3 shallow fissured, the apex is sharp, the lateral lobes are almost at an acute angle, and the outer edge base has short lobes and teeth;The short branches and leaves are flat cut at the base, and the notched teeth on both sides are almost symmetrical, with few hairs below.Only male plants can be seen.
It is cultivated in Xinjiang, China.It is distributed in southwest Europe, West Asia, Central Asia, etc.
The crown of the glossy white poplar is like that of the white poplar, but the bark is green, gray and smooth;The long branches and leaves are deeply split, the teeth on both sides of the short branches and leaves are almost symmetrical, the base is flat, and the back of the leaves is almost hairless.[1]
2. Xinjiang poplar (variety)
White poplar
Latin name:Populus albavar. pyramidalisBge.
This variety has a narrow cylindrical or spire shaped crown.The bark is gray or greenish gray, smooth with few cracks.The sprouts and long branches and leaves are palmately divided, and the base is flat;The short branches and leaves are round, with coarse missing teeth. The lateral teeth are symmetrical, the base is flat, and the lower part is green, with few hairs.Only male plants can be seen.
It is often cultivated in various provinces and regions in northern China, and Xinjiang is common.It is distributed in Central Asia, West Asia, Balkans, Europe and other places.[2]
Reproductive methods
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The propagation mode of Populus alba is to bury strips and root tiller.[9]
Site selection
White poplar
The sandy loam soil with less salt content, good ventilation condition and high fertility shall be selected. After thawing in spring, the soil preparation time shall be about 25~30cm deep. After leveling the soil, weeds and stones shall be removed.The seedbed is 20~30m long, 10~20cm high, 120~130cm wide bed bottom, 110cm wide bed surface and 30~40cm wide footpath.Spray 30~45kg/hm2 of pesticide phoxim sulfate and 30~40kg/hm2 of dixon fungicide in combination with land preparation, and apply fully decomposed manure, 2000kg or 50kg of calcium superphosphate every 667m2, and fill with bottom water to wait for cuttings.
cuttage
White poplar (Figure 3)
The middle and lower parts of 1-2 year old smooth and sturdy branches, plump and pest free, are selected as cuttings. The cuttings are picked back in the cellar at the beginning of November, buried in layers of wet sand, and the top layer is covered with 20cm sand. At the end of March, the cuttings are taken out and cut into 12~14cm cuttings. It is not necessary to cut the cuttings by buds, but only the upper part of the cuttings is flat and the lower part is inclined.Each 100 ears is a bundle and stored in the cellar. The method is to disinfect the river sand with 0.3% potassium permanganate solution, place the cuttings with the slant mouth facing down, and lay a layer of 10cm thick river sand on each layer, so that the sand can be kneaded into a ball. If the water content is too large, it is easy to rot.
The cuttings after overwintering in sand storage are beneficial to cortex softening and material transformation. The survival rate of spring cuttings is 2-3 times higher than that of spring cuttings, autumn cuttings and autumn cuttings, and the ground diameter is 20%~30% thick.Therefore, overwintering cuttings are often used to breed seedlings.The cutting is carried out around the middle of April after the soil thaws. Before cutting, the seedling field is irrigated with bottom water, and the operation is started when people can go down to the ground after 3 days of irrigation.Before cutting, take out the cuttings and wash them with water, then soak them in rooting powder for 24 hours.The cutting depth can be controlled at the top of the cutting and parallel to the ridge surface, with 6 rows per border and a plant row spacing of 15 × 25 (cm). In order to make the soil closely combined with the cutting, on the ridge after cutting, the cutting root must be closely contacted with the soil, so that the survival rate can be improved without gaps.
The requirements for soil moisture conditions are high during the cutting and seedling raising of white poplar. In addition to irrigation immediately after cutting to make the cuttings closely connected with the soil, the maximum field water capacity should be maintained at 60%~70% during the rooting period (May~June) of cuttings.During the fast-growing period (July to September), when the temperature is high, the seedlings grow rapidly, and the maximum water holding capacity in the field should be about 80%.At the later stage of seedling growth (from mid September to seedling defoliation), the growth gradually decreases. The soil moisture only needs to maintain the survival of the seedlings. Irrigation should be as little or no as possible, so as to improve the lignification of the seedlings and make them well prepared for overwintering
apply fertilizer
Top dressing should be carried out at the peak of seedling growth acceleration. 75 kg urea should be used for each mu of land, diluted to a concentration of 0.2%~0.5%, or applied dry, and the soil should be loosened immediately after application.During the fast-growing period from July to August, 75 kg of urea will be used for one mu of land, and no fertilizer will be applied after the middle of August, so as to facilitate the lignification of seedlings, enhance their cold resistance and safely overwinter.
Pruning
There are many lateral branches on the seedlings of silver white poplar, so it is necessary to prune in time, pay attention to the pruning time, affect the growth of seedlings too early, reduce the quality of seedlings too late, and prune and pick buds at the right time to improve the quality of seedlings.At the same time, the pressed seedlings can get light, reduce diseases, and accelerate the growth of weak seedlings.[3]
Pest prevention
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The forest management measures shall be strengthened with the focus on prevention. The disease resistance of white poplar is strong and it is not easy to cause great harm. In case of damping off, 800 times or 1% - 3% ferrous sulfate solution shall be sprayed once every 10 days to drench the soil surface of the seedbed, for a total of 2-3 times.Rust: spray 65% of the disposable zinc daisen solution 500 times or 50% of the disinfectant solution 500 times.Sodium dichloride 200 times liquid.Black spot: spray 1:1:200 Bordeaux solution or 65% of Dyssenz 250 times solution and 4% of Dyssenz powder once every 10-15 days.The main insect pests are: poplar winged moth, poplar longicorn.The prevention and control methods are as follows: before and after the adult emerges, use toxic mud to block the wormhole; before and after the adult lays eggs, avoid pruning and mechanical damage to prevent the adult from laying eggs at the wound; for the poplar longicorn beetle, you can also poison the eye wasp and the wasp for biological control.[3]
1. Choose the land with flat terrain, good drainage, loose and fertile soil to raise seedlings. Avoid using sticky heavy soil and the land previously used as melon, cotton, potato, vegetable, etc. as the nursery. Choose sunny days to prepare the land, build a fine bed, use yellow soil to cushion the bed with a thickness of 1~2 cm, and then sow seeds.
2. Select seeds, do a good job in accelerating germination, timely sow, timely uncover grass, dry irrigation and waterlogging drainage, and ensure that seedlings emerge neatly and are strong.
3. When sowing, medicinal soil can be sprinkled on the seedbed or in the sowing ditch.The pesticide soil can be prepared with the following pesticides:;Dixon 1~1.5 kg per mu;Sunong 6401 2.5~3 kg per mu;Pentachloronitrobenzene substituted zinc mixture (1:1) 2.5~3kg per mu (suitable for use in northern China), mix pesticides with 30-40 times dry fine soil evenly;Or 15~20 kg ferrous sulfate shall be used for crushing and spraying per mu.
4. The above soil can also be sprayed during seedling onset.If the soil is dry in sunny days, spray 500~800 times of Dixon solution or 800~1000 times of Sunong 6401 wettability agent or 1~3% ferrous sulfate solution. If the soil surface of the seedling bed is wet, ferrous sulfate will cause harm to the seedlings. After application, spray clean water to wash the seedlings.The soil or liquid medicine is applied once every 10 days or so, two to three times in total, which can inhibit the development of disease.According to local experience in Guangdong, 5000 times liquid or 8:2 lime powder of plant ash can also be effective.
rust
White poplar (Figure 4)
Symptoms: During the poplar leaf spreading period in April in spring, the overwintering diseased buds and germinating young leaves are covered with yellow powder piles, which look like a bunch of deformed diseased buds of yellow hydrangea.The seriously invaded diseased buds will dry up after about 3 weeks.The leaves are susceptible to disease after spreading, and yellow powder piles are scattered on the back, which are the summer spores of the pathogen. The tender leaves shrink, deform, or even die.Hardened leaves are rarely susceptible to disease.Oval disease spots on petioles and shoots also produce yellow powder.The diseased leaves may sometimes have ochre scar shaped dots in the spring of the next year, which is the winter spore pile of the pathogen.
Prevention methods:
1. Select and plant disease resistant varieties of Populus tomentosa with sparse branches, small leaves and cut leaves.
2. When sprouting in spring, use the special color and shape of the diseased bud to remove the diseased bud as soon as possible, and burn it in bags or bury it deeply.
3. In the tender leaf stage, spraying 50% of the 800 fold solution of bacteriophage or 0.2~0.3 ° Be sulfur mixture for 2~3 times can alleviate the disease.Due to the sensitivity of Populus tomentosa to triadimefon, it is easy to cause harm when used, so it should be avoided.
5. Remove diseased leaves in the field and burn them to reduce reinfection.
Black spot
See white poplar black spot.
Parathrene tabaniformis Rottenberg
Morphological characteristics: adult body length is 11~21mm, wing span is 23~39mm.It looks like a wasp.The head is semi spherical, surrounded by orange scales between the head and chest, and beige scales on the top of the head.The front wing is longitudinally narrow, with ochre scales, and the middle chamber and rear edge are slightly transparent.The hind wings are transparent, and the marginal hairs are grayish brown.The abdomen is cylindrical, black, with 5 orange yellow bands.Oval shaped, black, with gray and white irregular polygonal patterns.The mature larvae are 30mm long and cylindrical.The first instar larvae are light red, and yellow white when they are ripe.There are 3 pairs of chest feet, and the abdomen feet and buttocks feet are degenerated, leaving only toe hooks.The pupa is 12-23 mm long, spindle shaped, brown.The abdomen has 2~7 segments, with two rows of barbs on the back, and one row of barbs in 9 and 10 rows.Hip spines at the end of abdomen.
Prevention methods:
1. Select insect resistant tree species, such as some hybrid poplar trees, which have strong resistance to the white poplar diptera.
2. Strengthen quarantine. When importing or exporting seedlings, conduct strict inspection. If galls are found, they should be cut and burned to eliminate the source of pests.
White poplar
3. When the larvae are first eaten by artificial prevention and control, if there are any moth chips or small tumors, they should be cut off or cut off in time, or hook and stab the larvae at the defecation of the galls.Cut the galls and burn them when pruning in autumn.
4. Chemical control When the larvae invade the branches and there is obvious excreta on the surface, 50% Phosphamine emulsifiable concentrate and 20-30 times water can be used to apply a circular drug band, or drip or inject boreholes to kill the larvae.Use carbon trisulfide cotton balls to plug the boreholes and block the slime outside the holes, which can kill the larvae that dive into the depth of the tunnel.At the initial invasion stage of larvae, apply deltamethrin slurry (1 part of 2.5% deltamethrin emulsifiable concentrate, 5~10 parts of yellow clay, and add appropriate amount of water to synthesize slurry) on the injured stems and branches to poison the newly hatched larvae.Seize the opportunity when the newly hatched larvae have not yet penetrated the tree trunk, spray 1:500~1000 times of dichlorvos on the tree trunk and branches, and spray once every 9 days, with good toxic effect.[4]
Key values
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Medical value
Anhui Traditional Chinese Medicine: "cough relieves asthma, clearing heat and resolving phlegm".[10]
economic value
The wood of white poplar has straight grain, fine structure, light and soft quality, and can be used for building, furniture, paper making, etc;Bark can be used to make tannin extract;Grinding leaves can drive away bedbugs;[8]
Virescence value
The white poplar has a towering tree shape, beautiful branches and leaves, and red young leaves, which can be used as a greening tree species.[8]The silver white poplar is still large, and its silver white leaves are swaying in the breeze. Under the sun, it has a unique relaxing effect. It can be used as a shade tree, street tree, or isolated or clustered on the lawn.[7]
