Cultivation technology for the propagation of pu trees and the control of pests and diseases
The tree is a large deciduous tree of the genus Pu in the elm family. Hermaphroditic, grey bark, leathery leaves, glabrous, broadly ovate or oval ovate. The flowering period is from April to May, and the fruit period is from September to October, and the fruit is nearly spherical.
Pu tree is a positive tree species, like light, slightly shade-tolerant, water-resistant, not strict on soil requirements, has a certain drought tolerance, in the slightly acidic, slightly alkaline, neutral and calcareous soil can grow. The tree has a wide canopy, rich shade, autumn leaves turn golden, and bright colors, and are the main tree species in the courtyard and park. It can be planted alone, group planted, and can also be shaped into stumps and bonsai, which has high ornamental value.
Reproduction
Plain trees can be propagated by sowing seeds and cuttings, and the production is mainly based on sowing and propagation.
Sowing and propagation
(1) Seed collection and processing. The seeds ripen in October and are collected when the fruit of the tree changes from cyan to yellow-brown. Manually knead the pulp, remove the net seeds, rinse repeatedly with water, and dry in the shade. Select seeds with full grains, no defects or deformities, and sow in the spring after winter sowing or stratification germination. The production is mainly based on spring sowing after layering. Layer accumulation germination: Choose a dry and ventilated room that cannot be illuminated by sunlight, first lay 1 layer of wet sand with a thickness of 10 cm on the ground, and then stack the seeds and the wet sand in layers of 1. 3 layers, stack 40 cm high, and then cover the wet sand with a thickness of 10 cm, and insert several perforated bamboo tubes or straws on the sand pile to breathe. The humidity of the sand is advisable to hold the hand into a clump and loosen several large cracks. If there are not many seeds, the seeds and wet sand can also be mixed into perforated wooden boxes and baskets, and checked frequently in winter to prevent the seeds from rotting due to excessive sand.
(2) Garden finishing. Neutral loam soil with flat, fertile terrain and easy access to transportation and water sources was chosen as a nursery. Remove the roots, bricks, plastics, weeds and other debris on the garden before tillage.
a. Land preparation. In the late autumn or early winter of the first year, the garden is deeply turned 1 time, up to 35cm, without rake, after a winter (about 2 months) of drying and freezing, which is conducive to soil weathering, changing the physical and chemical properties of the soil, and reducing the occurrence of diseases and insect pests. Combined with the rural winter leisure, the drainage ditch (commonly known as the fence ditch) around the nursery is excavated, with a width of 40cm and a depth of 35cm, so that it can be drained. In mid-to-late February of the following year, 2000 kg of fully decomposed manure, or 150 kg of decomposed cake fertilizer, or 75 kg of potassium sulfate compound fertilizer were applied per mu of garden land. Each mu of land can be equipped with 100 kg of calcium superphosphate to improve soil fertility and facilitate the absorption and survival of young plants. After applying the fertilizer, the nursery land is continuously rake for 3 to 4 times, so that the nursery land is fully flattened, the soil particles are fully rake, and the fertilizer is evenly mixed in the soil.
b. Ditching to make a bed. In order to prevent sunburn from harming seedlings, the seedbed is mostly in a north-south direction. Manually use the 1.5m wide wire to open the groove as a seedbed. Among them, the seedbed width is 1.2m, the width of the compartment groove is 30cm, and the depth of the ditch is 25cm. The length of the seedbed is controlled within 15m, and the middle ditch must be opened if it is too long, so that the "three ditches" of the enclosure ditch, the middle ditch and the box ditch are connected. Deep trench narrow bed, conducive to drainage and irrigation and personnel operations.
c. Disinfection. It is best to carry out a pesticidal treatment before sowing. Sterilization can be sprinkled with fine soil mixed with ferrous sulfate granules (15 ~ 20kg/ mu) and 70% dixone wettable powder (1 ~ 1.5kg/mu), and the effect is good. Insecticide can be sprinkled with 3% of the carbufuran granules 5 kg per acre.
(3) Sowing. In March to April, the germination of the seeds of the tree is often checked, and when 30% of the seeds begin to whiten, the seeds of the tree after the accumulation of germination are sieved out with a sieve to remove the mold seeds, further carefully selected, washed and drained with water and sown. Artificially drawn lines to open a strip sowing ditch, row spacing 25cm, ditch depth 2cm, the seeds of the tree are evenly sown in the ditch, covered with fine soil 1cm, and can be sprayed with 50% acetochlor emulsion to seal the soil to control weed breeding. Cover with pine needles, sawdust, straw, etc. to keep the moisture breathable. After sowing, according to the weather conditions and soil moisture, appropriate watering, to maintain the appropriate humidity of the seedbed. About the end of April, when the emergence reaches 50%, the straw is removed in two batches, and the pine needles are removed at intervals of about 10 days and diluted with 50% carbendazim wettable powder diluted 1000 times the liquid spray sterilization. Properly managed, the seedlings sown that year can reach a height of about 100 cm.
Propagation of cuttings Of the simple tree is divided into hard branch cuttings and young branch cuttings.
(1) Hard branch cuttings. Hard-branched cuttings of the tree are mostly carried out in early spring in early March, with lignified branches.
a. Nursery preparation. The cuttings of the tree are arranged in the same sowing garden, but no fertilizer is applied, and the seedbed is made into a turtle back shape to facilitate drainage. Set up a shade according to the area of cuttings and cover 50% of the shade net. The nets are connected to each other by wire or strong ropes, and the nets are secured by wire or rope around them. Shade shelters must be sturdy and able to withstand high winds. Calculate the cutting time and use 1000 times the liquid potassium permanganate 24 hours in advance to water the seedbed thoroughly to sterilize.
b. Cuttings for ear picking. In early March, large trees with robust growth and no pests and diseases are selected and strong branches that are 1 to 2 years old before the trees are fully lignified are cut. The harvested branches are piled up in the cool leeward for short cutting, the length of the cuttings is 10 to 12 cm, leaving only the upper part of 1 to 3 buds, the upper end of the cuttings is flat sheared, and the lower end is obliquely cut into a horse ear shape. Cut the 30 spikes into 1 bundle, aligning the lower parts. The lower end is soaked in 100 mg/kg of abt1 rooting powder solution for 2 hours to cut the cuttings. The depth of the cuttings is 2/3 of the cuttings. After inserting 1 compartment, quickly water it with a watering can so that the cuttings are in full contact with the substrate. A small arch is built with bamboo pieces, and the middle film is covered with a width of 2m, and the middle film is surrounded by stones or soil to keep warm. Hang a thermohygrometer in one of the vaults.
c. Post-insertion management. After the cuttings of the tree tree, the main thing is the management of temperature and humidity. In the early stage of cuttings (within 30 days), the relative humidity of the air in the small arch should be kept above 90%. After about 30 days, the cuttings wound begins to heal and take root. When all the cuttings are rooted and more than 50% of them begin to leaf, the two ends of the film must be removed to ventilate the seedlings. After proper refining, remove the film and shade net to increase the resistance of seedlings, but the suitable humidity of the seedbed should be ensured. Every 10 days, decaying and dead cuttings are removed and burned or buried. Spray sterilization with 50% carbendazim wettable powder diluted 1000 times at intervals of 7 to 10 days.
(2) Cuttings of young branches. The young branches of the simple tree are mostly cut from May to July, and the cuttings are made from the semi-woody branches of the year. Mostly carried out in the all-light intermittent spray greenhouse, mainly using the semi-woody branches of the simple tree with the characteristics of vigorous cell division, strong vitality, and easy survival of cuttings.
a. Laying seedbeds. From May to July, a seedbed is laid in an all-light intermittent spray greenhouse (covered with imported plastic film), the length of the seedbed is controlled within 15m, the width is 1.2m, and the gap between the seedbed and the seedbed is 30cm. The seedbed is paved with a mixture of vermiculite, perlite, peat and other substances. To save costs, loam soil can also be directly used to pave the bed with river sand, and the seedbed is fixed with a 15 cm high wooden plank or slate around the seedbed.
b. Cuttings for ear picking. After the seedbed is set, strips are picked before sunrise in the early morning or on rainy days. Keep the harvested shoots indoors and moisturize them with a foliar spray. Prune the branches into 8 to 10 cm with 1 to 2 leaves, and dip the base of the cuttings in 1000 mg/kg of iba (indole butyric acid) solution for 5 to 10 seconds, drain slightly to extract the cuttings. The density of cuttings is appropriate to not cover the leaves with each other, the depth of cuttings is 1/2 of the cuttings, and the spray moisturizer is quickly sprayed after inserting a box to prevent the cuttings from dehydration and loss of vitality.
c. Full light intermittent spray management. After the spikes are cut, the all-light intermittent spray is used for management. Until the cuttings heal and root, the air humidity in the plastic greenhouse should be kept above 95%. Generally, when the water film of the leaves of the tree evaporates to only 1/3 of the time, the spray starts, the interval is about 10 to 30 minutes on sunny days for 10 to 30 seconds, and the number of sprays is reduced on rainy days and nights, and the interval time is increased. About 20 days, the seedlings begin to heal and take root, which can be sprayed after the leaf surface water film has completely evaporated, and when the cuttings are rooted, they can only be sprayed around noon on sunny days, and not sprayed on rainy days and nights. In short, it should be flexible according to weather conditions. Every interval of 10 to 15 days, the decaying cuttings of the tree are pulled out and burned or buried. Dilute 1000 times with 70% methyl tolbucin wettable powder to sterilize the sap, and the seedlings can be transplanted to the field in the spring.
Seedling management
Intermittent seedlings, supplementary seedlings When the seedlings sown by the simple tree grow to 5 to 10 cm, the seedlings can be inter-seedlings, and the inter-seedlings can be combined for re-seedlings. Use a small sharp spatula to gently dig up the dense young saplings, then replant them in the sparse area of the garden and water them steadily. The principle of inter-seedling should follow the principle of "leaving a large one in the interval, leaving a thin space between the small, leaving a thin one, leaving the inferior and leaving the superior, and the whole seedling equidistant" to keep the seedbed seedlings evenly distributed.
Loose soil weeding After the seeds of the simple tree germinate or the cuttings are in viable, the weeding should be carried out according to the actual situation in the garden and greenhouse. Weeds in sowing seedbeds, furrows, middle ditches and ditches can be directly eradicated with hoes to increase soil permeability and prevent soil compaction. For the cuttings of the simple tree, a small sharp shovel should be used to remove weeds a little bit, and the loose seedlings should be watered steadily. In general, weeds need to be removed twice a month in April to July, and once a month from August to October. In order to prevent weeds and seedlings of simple trees from competing for fertilizer, water and light, it is conducive to the growth of seedlings.
Water and fertilizer management Reasonable irrigation is the premise of the normal growth and development of seedlings sown by the tree. Before and after the emergence period, in order to avoid drying of the soil surface of the nursery, the principle of watering is a small amount of times. Pay attention to drainage during the rainy season. In the summer drought, it is necessary to increase the number of watering and try to water thoroughly. Water less in autumn and no water in winter. In peacetime, it is necessary to strengthen the dredging and dredging of the surrounding ditches, middle ditches, and box ditches to ensure that irrigation and drainage are smooth. From June to August, the seedlings sown to the simple tree can be combined with watering for topdressing, and urea can be applied 5 to 10kg per acre of seedling field, and the seedlings can be washed while applying watering to prevent the formation of fertilizer damage. Stop topdressing at the end of August to promote lignification of seedling shoots and facilitate overwintering. Foliar spray of 0.2% to 0.3% potassium dihydrogen phosphate can be used for pushu cuttings, once every 10 to 15 days, and more than 3 consecutive times, which can effectively promote the growth of cuttings
Pest control There are fewer pests and diseases in the trees. Insect pests include aphids, stinging moths, wood lice, American white moths and other harmful roots, stems and leaves of the tree, which can be controlled by 80% of the dichlorvos emulsion 1500 times liquid spray. Diseases with root rot can be spread in soil with 70% dixone wettable powder for seedling prevention, and 70% dixon or 70% methyl tolbutzin wettable powder can be diluted with 1000 times liquid spray or root irrigation for tree control.
Large tree and bonsai shape
Large tree shape The digging and planting of large trees should be carried out in the autumn and before the budding in the spring. Wild stumps can be cut in place at one time, and the distance between the stumps and the stumps is 4m×4m. Water the roots with a 100 ppm abt solution so that the soil is in close contact with the roots and often remain moist afterwards. After 2 to 3 years of stumps to become live branches, according to the pile shape, with a diameter of 20 ~ 30 ~ 40 ~ 50 ~ 60 cm and other bamboo circles.
Climb the tree with a wooden ladder and tie the branches on the bamboo circle according to the principle of first the main branch and then the side branches, first up the branches and then the lower branches. Depending on the situation, the branches are pulled and climbed with thin wire and fixed to the surface of the bamboo circle. The upward development branches on the surface of the bamboo circle are flat-cut, about 3 to 4 times a year. Through repeated fine pruning, the branches are enriched and the leaves are dense, so that the branches develop around the plane and can be formed in 5 years. Often a large tree has multiple planes. Compound fertilizer is applied to large trees 1 to 2 times a year, and the purpose of topdressing is achieved through water infiltration, which promotes robust growth and plump branches and leaves.
Bonsai cultivation First of all, the branches and leaves of the simple tree pile are properly pruned, the pastoral soil or the configuration of nutrient soil is selected, the superfluous main root is cut off from the simple tree stump, more whisker roots are left, the pot is potted, the soil is cultivated, and the bonsai pile culture is carried out. After 1 to 2 years of bonsai pile cultivation, a combination of pruning and pruning is adopted, and the pruning and tying skills are emphasized, and the shape is carried out according to the pile shape. The shape has straight dry type, oblique dry type, curved dry type, horizontal dry type and other shapes. During the growing season, a thin liquid fertilizer of decomposition can be applied, and when the potting soil is dry, it can be properly watered and sprayed on the leaves. After several years of pruning, the bonsai of the simple tree can be cultivated and has its own characteristics. Even after the leaves fall in winter, the shape is full of masculine beauty.