Propagation and cultivation of Cercis gigantea and high planting of Cercis canadensis with purple leaves

In recent years, the application of Cercis gigantea in landscape engineering has been gradually recognized and valued by people. It is famous for its tall trees, straight trunks, dense and elegant branches, strange heart-shaped leaves and brilliant flowers. At the same time, the cultivation of new varieties of high-end colored leaf trees by high grafting of Cercis chinensis has been well received by the industry.

1 Overview of Cercis gigantea

Morphological characteristics of 1. 1

Bauhinia. It is a deciduous tree with an umbrella crown in Leguminosae. It was named Bauhinia. It is a fast-growing and long-lived tree. DBH can reach 55cm and 20m. Simple leaves alternate, thin leathery, heart-shaped or nearly round, entire, short blade tip, transparent edge, smooth surface, 6 ~ 13 cm long; Young leaves are purplish red, adult leaves are green, and petioles are reddish brown. The bark of the big tree is gray-black, with longitudinal cracks, the new branches are dark purple-green, hairless, and the lenticels are light gray. Racemes, flowering from March to April, the first leaves are open, clustered on old branches, and the corolla is purple, resembling a butterfly, and the flowering period is half a month. Fruit period 10 month, pod strip, purple. Seeds are dark green, nearly round, 5~ 1 1, flat.

Biological characteristics of 1.2

Bauhinia is adaptable, cold-resistant, drought-resistant, salt-tolerant, sun-loving, waterlogging-resistant, and strict in soil quality. It can grow in fertile and acid-base soil, but it grows best in deep fertile and well-drained soil. Bauhinia has the characteristics of rapid growth, strong sprouting ability, pruning resistance, pest resistance, strong resistance to sulfur dioxide, hydrogen fluoride and nitrogen, rhizobia and so on, and generally grows in the foothills and ravines of sunny slopes at an altitude of 300~ 1200m. Cercis gigantea is distributed in Lin 'an, Zhejiang, Huoshan, Anhui and Luanchuan, Guizhou. The giant bauhinia in Yi 'an District mainly grows in the three hills of Zhongming, Shun 'an and Tianmen, and is often scattered or clustered in broad-leaved forests.

The application value of 1.3

Giant Bauhinia has excellent material, dense texture, good toughness and strong corrosion resistance, and can be used as building and furniture materials. Bark, wood and roots can all be used as medicine, which has the effects of promoting blood circulation and qi circulation, relieving swelling and pain, removing blood stasis and detoxifying. The giant bauhinia tree has beautiful posture, stretched crown, lush foliage, heart-shaped leaves, round and shiny, light and shadow set each other off, moving and lovely. The branches of the giant bauhinia are soft and drooping, dense and elegant, and the leaves open first in early spring. No matter the big branches and small branches, they are full of purple flowers, like clouds, and brocade reflects the sky. The pods are dark red and strip-shaped, and the colors are beautiful and spectacular against the green leaves.

The giant bauhinia enjoys the reputation of "as tall as fatong and as bright as cherry blossoms". Suitable for growing in urban roads, river banks and other environments, with high ornamental value and broad application prospects in landscaping.

Propagation of giant bauhinia

2. 1 seed collection and processing

Select robust, plump, pest-free and well-shaped Cercis gigantea, collect mature seed pods in late June 10 to 10 in early October10, put them in a ventilated place for a few days, and then take them out to sun 1 ~ 2 days, and the pods begin to grow. The treated seeds can be put into breathable bags and stored in a cool and ventilated place for dry storage or sand storage until sowing in the next year.

2.2 Sand bed germination

2.2. 1 Build sand layer. Choose a flat site with the leeward facing the sun, and set a hollow brick sand bed according to the east-west length 15~20m and the north-south width1.2m. The height of the bed near the north is 50cm, and the height of the bed near the south is 30cm. The sand bed is covered with film inside and outside (except the bottom of the bed). The bottom of the sand bed is paved with melon seeds (gravel) with a thickness of 10cm, and then paved with 65433.

2.2.2 Seed germination. In early February, the seeds of Cercis chinensis were soaked in hot water at 80℃ for 20 hours, then washed, then soaked in 0.5% copper sulfate solution for 2 hours, washed with clean water and dried in the shade, evenly spread on the sand bed (seeds do not overlap), covered with coarse yellow sand with a thickness of 65438±0cm, and then sprayed with 75% carbendazim wettable powder 800 times to disinfect the sand bed. Insert the bamboo bow into the sand bed every 50cm, and then cover it with a 0.4mm thick film for moisturizing. Pay attention to the humidity and temperature in the bed every day. After emergence, the maximum temperature in the arch shed should not exceed 28℃, otherwise shading or ventilation should be conducted at both ends of the sand bed to cool down. After the seeds of Cercis chinensis grow into two true leaves, they are gradually ventilated for 7~ 10d.

2.3 Bud transplantation

2.3. 1 seedbed finishing. Choose sandy loam with flat terrain, abundant sunshine, good irrigation and drainage conditions and fertile soil. Before the end of that year 10/0, 1500kg of decomposed farm manure (chicken manure, pigeon manure or rapeseed cake) and 15kg of compound fertilizer (total nutrients ≥48%) and its 667m2 were evenly spread. Then, according to the width of 100cm, the height of 20cm and the path of 40cm, build high ridges (covered with film to prevent rain from affecting the transplanting of giant bauhinia sprouts) for later use.

2.3.2 Choose the timing of transplanting seedlings. Select continuous cloudy or rainy days, transplant Bauhinia bud seedlings with a spacing of 50cm×50cm, and then spray (fine spray) the bud seedlings with 1000 times of 75% carbendazim wettable powder.

2.4 seedling management

Spray the bud of Bauhinia with the same amount of Bordeaux solution every 10~ 15d on a calm sunny day, and disinfect the bud with 800 times chlorothalonil solution every 20 days. In rainy season, topdressing 0.5kg urea every 10d667m2, paying attention to intertillage and weeding to promote the rapid growth of seedlings. If there are leaf-eating pests such as moths at seedling stage, 500~800 times of cypermethrin can be sprayed for control.

3 giant bauhinia cultivation

3. 1 recovery

Choose loose and fertile sandy loam with good drainage. Before the end of 10 in that year, 3000kg of decomposed organic fertilizer (chicken manure, pigeon manure or rapeseed cake), 30kg of 48% NPK compound fertilizer and 5kg of granular phoxim were applied to 667m2, and the excavator dug it to 30~50cm to form more granular structures. Then, I raked it twice with a rotary tiller.

3.2 Planting density

Planted according to 667 plants /667m2 (plant row spacing 100cm× 100cm), and transplanted according to alternate spacing in the third year, keeping the density 167 plants /667m2.

3.3 planting time

Planting from mid-February to early March.

3.4 Planting method

Dig a 30cm×30cm planting hole, select 1 year-old Cercis gigantea, and plant it with bare roots dipped in mud. When the seedlings grow, don't plant them too deep, which is generally slightly lower than the original soil mark of the giant bauhinia. Seedlings should be planted upright, perpendicular to the ground, and the soil should be filled. After planting, root water should be thoroughly watered, the second water should be watered after 3 days of sunny days, and the third water should be watered after 10d.

3.5 flat stubble for drying.

The next year, before the sap flowed out, it was cut dry underground with a hand saw. The cross section should be smooth to prevent tearing. When the buds grow to 15~20cm, the branches with strong main wind direction are selected as the main culture and the rest are cut off. Axillary bud germination was found during the growth of Cercis gigantea trunk, which should be removed in time.

3.6 Tending management

3.6. 1 new tooth point traction. The giant Cercis chinensis has strong ability of sprouting tillers and huge leaves, and it is easy to bend the trunk because of falling branches, which is not conducive to cultivating a straight trunk shape. In spring, the new buds of Bauhinia should be pulled by bamboo poles with a diameter of 2~3cm (bound with plastic packing ropes, but not too tight) to prevent the new buds from sagging.

3.6.2 Soil moisture control. Always keep the soil moist when planting bauhinia. Bauhinia longifolia enters the peak growth period, and furrow irrigation is prohibited every 10~ 15d depending on the weather. After the drought in early autumn, furrow irrigation should be conducted every 15d. Pay attention to the field drainage in rainy season, so that the rain stops and the ground is dry, and there is no water in the field.

3.6.3 Clever fertilization. Bauhinia seedlings are very sensitive to fertilizer demand, and fertilization in growing season has a very obvious promoting effect on plant growth. After planting Bauhinia, due to the lack of fibrous roots and poor absorption capacity, only a small amount of nitrogen fertilizer (667m2 topdressing urea 65438+ 0.5 kg each time) is needed in rainy season 1 year. From the second year, topdressing compound fertilizer 10kg in late April, mid-May and early June, topdressing potash fertilizer 15kg in early July, early August and early September. During this period, cake fertilizer 150kg was applied every 667m2 border in winter.

3.6.4 Intertillage weeding. In the planting year of Bauhinia, manual weeding was adopted, which was carried out in early April, mid-May, late June, early September and mid-June of 10 respectively. After that, it will be carried out by artificial combined with chemical weeding every year (chemical herbicides will be used in ridges and border areas).

3.6.5 Fix the valve stem and cut it short. 1 year, removing the bud branches of Cercis gigantea in the range of 65438+50cm; Prune the lower branches of Cercis chinensis 1~2 times in the second year (or remove the big branches with a dry height of 2.4m or 2.8m according to the cultivation objectives); In the winter of the third year, the trunk of Cercis grandis was cut at the height of 2.4m or 2.8m, and all the lateral branches with the height of 2.4m or less were removed, and three branches were selected. When the height of trunk branches reaches 2.4m or 2.8m, and the height of trees is 4~6m, the pruning and shaping measures can be ended and the routine management can be started.

3.6.6 Pest control. Bauhinia is a plant with strong resistance to pests and diseases, and no major diseases and destructive pests have been found after years of cultivation. When Cercis chinensis suffers from angular leaf spot, leaf blight and stem rot, 75% carbendazim wettable powder is sprayed with 500-800 times of liquid; When aphids, moths and longicorn beetles appear, they are poisoned with 800 times of cypermethrin; After 200 times solution of avermectin is injected into the borehole (syringe), the borehole is sealed with thick mud. In winter, lime is used to paint the trunk of the giant bauhinia below1.2m.

Bauhinia canadensis

4. High grafting

Purple-leaf Cercis canadensis sealed with wax in spring (Cercis canadensis is a variety of Cercis canadensis, which is a small tree. Its leaves are bright purple in spring, summer and autumn, and its shoots are always magnificent red. It is a rare colorful garden ornamental plant with flowers and leaves in three seasons. It can be planted alone in the courtyard or lawn, or together with other green leaves and colored trees. To achieve the artistic effect of setting each other off), sunset bauhinia (sunset bauhinia is the bud change of deciduous shrub bauhinia, with flowers flying like butterflies, purple or bright red leaves, especially enchanting and naturally drooping branches, which adds to the beauty of flowers and leaves. It is a rare red tree with drooping branches, which can be used for garden flower beds and branches. The branches are upright and naturally open, shaped like an open golden sail; Leaves are golden yellow in spring, and yellow-green in summer and autumn. The young leaves of Bauhinia Jinfan changed from yellow to bright yellow, the petiole was 4~5cm long, the young petiole was chestnut, the new petiole was ginger, and the old petiole was yellow-green. It was an excellent colorful leaf tree species with both leaves and flowers. Using Cercis gigantea as rootstock, grafting was carried out by split grafting and skin grafting, and the fixed stem height of Cercis gigantea was 2.4m and 2.8m2, respectively.

In the summer growing season, in order to make up for the rootstock of Bauhinia which failed to graft in spring and achieve the purpose of expanding high-end colorful tree species, the new branches of Bauhinia were grafted by "T" bud grafting or grafting.