Cuttings should be harvested in late autumn and early winter, and the 1 annual branches sprouted on the trunk of seedlings or strong mother trunk are better, and 1 annual branches sprouted at the crown can also be used. In order to ensure the supply of cuttings, a cutting nursery with seedlings can also be established.

Cutting and cuttings processing

Cut the cuttings into 1.5 ~ 20 cm long immediately after harvesting, and leave two nodes and three whole buds for each cuttings, because there are more nutrients in the branches than in the internodes. The lower incision should be close to the node, generally about 1cm from the bud base, which is beneficial to healing and rooting, and the upper incision should be 0.5~ 1cm from the bud tip to prevent the terminal bud from wilting due to dehydration. Every 50~ 100 cuttings are bundled into 1 bundle, and then a pit with a depth of 60~80cm and a width of 80cm is dug on the leeward side with good drainage, and the pit length is determined by the number of cuttings. The bottom of the pit is covered with a layer of virtual soil, and the cuttings stand upright on the virtual soil with their heads down. Finally, cover the soil, cover it into a ball to prevent rainwater from infiltrating, and take it out for cutting the next spring. Harvesting and transplanting can also be done in spring, and the survival rate is also high.

Cutting propagation method

Before cutting, you should choose a well-drained, loose and fertile plot, and make it into a cutting bed after deep turning, disinfection and leveling. In early and mid-March, the cuttage bed was irrigated for 65438 0 times, and the whole cuttage bed was covered with plastic film after seepage. At this time, the cuttings stored in the sand are taken out and soaked in rooting agent 1000 times for 2~3 days, and the rooting agent 1 times is changed every 24 hours. After the ear dipping is completed, the cuttings are carried out according to the plant spacing of 15cm×30cm. Before cutting, punch a hole with a hard stick with the same thickness as the cutting, with a depth of about 10cm, and then cut, with the cutting exposed to the ground for about 5cm. After the whole bed is inserted, the cuttings are sealed with fine soil to make the cuttings closely contact with the soil.

Seedling management

There are secondary buds and latent buds on both sides of main buds on Platanus acerifolia cuttings. Sometimes the leaf buds germinate before rooting, forming a false phenomenon, but the new branches soon die, and secondary buds grow after about 10 days, indicating that the new young roots have grown and the cuttings have survived. After rooting, when the sprout height is 6 ~ 10cm, leave 1 strong branch to cultivate the trunk, and cut off the rest. If withered buds are found, you can remove 1~2 leaves, or remove the main buds and keep the secondary buds. During the growing period, when the branches and leaves are too dense, the branches should be cut off twice, the yellow leaves should be removed, and ventilation and light should be maintained. At the same time, it is necessary to keep the seedbed moist frequently to facilitate the cuttings to take root. After the cuttings take root, apply quick-acting fertilizer, mainly urea, in June-August. Weeding is also important to protect seedlings. Don't wait for the weeds to grow tall before weeding. Try to "weed early, weed small". There are fewer diseases in the growing period, but attention should be paid to the prevention and control of aphids. If carefully managed, the height of seedlings can reach more than 1.5m in that year, and can be planted in the field after 1 year, and can be used for urban greening when they are 6 years old. Seed treatment is different from other tree species, and the seeds of cortex fraxini will fall to the ground when they mature. When its fruit ball is ripe, it can be hung on a tree and will not fall down all winter. Therefore, before the next spring comes, you can pick the fruit balls, put them in sacks, and then gently beat the sacks with wooden sticks to break all the fruit balls, so that all the seeds will be played out. However, fluff often adheres to the seeds of paulownia, and these fluff and seeds must be peeled off to obtain pure seeds, otherwise the attachment of these fluff will keep the seeds from contacting the soil. The specific method is as follows: after the fruit ball is broken, the small ball center in the middle of the broken fruit ball is picked up, the screen is repeatedly rubbed on the iron screen by hand to separate the fluff from the needle-like seeds, and then the seeds are separated from the fluff by air separation to obtain the net seeds, which are bagged and sowed.

Seedbed preparation Seedbed is best selected in fertile and non-hardened agricultural land, which is sheltered from the wind, with smooth drainage, perfect irrigation equipment, convenient water intake and no saline-alkali land. After selecting the seedbed, you should water and irrigate it first, and then apply sufficient base fertilizer. Generally choose decomposed farmyard manure. After fertilization, the seedbed should be deeply ploughed and leveled, and the shallow ditch should be ridged. The ridge should be consistent with the irrigation direction and connected with the ridge. Ridge length10m, ridge height 0.15m, ridge bottom width 0.6m, ridge surface width 0.3-0.4m, irrigation ditch bottom width 0.3m, gully mouth width 0.6m, and the ridge slope is firm.

Generally, spring is the best sowing time, and the specific time depends on the local climate. Generally, when the average daily temperature keeps stable above 15℃, you can start sowing. The northern region is suitable for sowing in late April and early May, depending on the specific climate. If it is advanced or postponed, it will have a great impact on the emergence and growth, which should be paid attention to.

Before seed treatment and sowing, the seeds can be soaked in cold water for a day and night, and fresh water is changed every 65,438+02 hours, and then the soaked seeds can be heated by light under windless conditions or in a greenhouse. After heating, the seeds can germinate quickly and evenly, and it is best to ensure that the storage environment temperature of the seeds reaches 28℃~30℃, so that the seeds can be exposed to the sun within one or two days.

Sowing techniques should be sown in the evening, preferably on cloudy days. Scatter the seeds evenly on the ridge surface with higher density, and then cover them with Qinghe sand. River sand should be prepared in advance, without alkali. The thickness of river sand should be based on the fact that the seeds of Indus can't be seen, not too thick, otherwise it will affect the germination of seeds, and not too little. If it is too little, it will cover incomplete seeds, making them easy to dry and lack water, which is not conducive to germination. After mulching, gently suppress it to ensure that the seeds are closely combined with the soil on the ridge surface, which is conducive to rooting.

After field management and sowing, Miao Di should be irrigated slowly to avoid floods and rapids, so as not to break the ridge surface. Irrigation depth shall be subject to slow infiltration into the surface of the ridge. After irrigation, always observe the humidity on the ridge surface and spray water twice a day, morning and evening. Spray slowly, not too quickly, to prevent the seeds from being washed away and affecting germination. Emergence begins after one week, and normally occurs within two weeks. Within 45 days after sowing, except furrow irrigation after sowing, furrow irrigation was conducted for 65,438+0 times every 7 days, and ridge spraying was conducted for 65,438+0 times in the morning and evening.

June-August is the vigorous growth period of Platanus acerifolia seedlings, so it is necessary to do a good job in timely topdressing, irrigation, wiping side branches, intertillage weeding, pest control and other management work. Topdressing can start in mid-June. The first topdressing can be ditched along the slope bottom on both sides of the seedling ridge. The top dressing should be mainly decomposed manure, and the other is quick-acting fertilizer. Irrigate immediately after each topdressing, and irrigate 6-7 times from the first topdressing to the end of August. In order to enhance the lignification strength of seedlings, stop watering before autumn. Within two months of 10 ~ 1 1, depending on the soil moisture in the nursery, small furrow irrigation was used 1~2 times, and the overwintering water was filled before the end of 1 1 to ensure safe overwintering. The best planting time of Platanus acerifolia is March in spring, and the root system should be no less than 10~ 12 times of DBH. For big seedlings with DBH above 5cm, in order to ensure survival and reduce transpiration, before planting, the stem can be fixed at a height of 3~3.5m, and all the branches on it can be smoothed. Apply antiseptic to the incision, and use white ready mixed paint or lime milk. Immediately after planting, water 1 time, then water 1 time every 7 days, thoroughly water for 3-4 times continuously, and then cultivate and loosen the soil. In autumn, apply 50 ~ 75 kg of organic fertilizer to each plant, water it stably, and cultivate the soil at the base of the trunk to prevent cold and winter. With such meticulous management, the survival rate can reach about 98%.

Plastic trimming

1, select a tree. Platanus acerifolia has straight trunks and branches, and usually has a wide natural crown. When making street trees, the shape is generally cup-shaped. If there is no overhead line on it, you can be happy. When making shade trees, they are mainly naturally straight or multi-branched.

2, plastic trimming. In the winter of the following year, the stem was fixed, the tip was cut off at the height of 3~3.5m, and the side branches on the trunk below the branch point were cut off. In the third year, after the seedlings germinate, 3~5 strong branches near the branches are selected as the main branches, and the rest are cut off in batches. In winter, cut off the main branches by 50 ~80cm, and leave the cut buds on the side to make them as horizontal as possible. After germination in the next spring, two 3-level lateral branches are selected to grow obliquely, that is, the shape of "three branches, six forks and twelve branches" is formed. After 3-4 years of cultivation, the diameter at breast height of the big seedlings is 7-8 cm, which has initially shown the shape of a cup-shaped crown, which meets the standards of street trees and can be taken out of the nursery. After planting, the cup-shaped street trees should be pruned for 4-5 years as in the seedling stage until the crown has 4-5 lateral branches. After the annual dormancy period, the branches of that year will be born. The main pests that harm Platanus acerifolia are Anoplophora glabripennis, Anoplophora glabripennis, Black Moth Six Star, and Eupolyphaga fusca. In the prevention and control, various methods such as artificial capture or black light trapping and killing adults, killing eggs, cutting insect branches and centralized treatment were adopted. During the emergence of adults and newly hatched larvae, chemical agents can be used to spray branches or tree crowns with 40% omethoate EC, 50% phoxim EC, 90% trichlorfon crystals and 25% deltamethrin EC 100~500 times. Prevention and control of larvae that have eaten into xylem by injection and hole plugging. For most larvae of Cerambycidae and Cerambycidae, the following methods can be used: dip 1~50 times of dichlorvos, omethoate, deltamethrin, etc. with a syringe or cotton wool. Enter the wormhole; The wormhole is blocked with aluminum phosphide or zinc phosphide poison stick and sealed with yellow mud, and the effect is good. Fungal blight of paulownia is the main disease, which can be controlled by changing stubble and raising seedlings. Repeated stubble is strictly prohibited. In autumn, the fallen leaves of seedbed are collected and burned to reduce the source of overwintering bacteria; From late May to July, spraying 1: 2: 200 times of Bordeaux solution on the leaves of seedlings for 2-3 times has the effect of preventing diseases.