Photo of Catalpa bungeana in the Forbidden City

Catalpa trees have tall and straight branches and light red and elegant flowers. Since ancient times, Catalpa bungeana has been widely planted in

Photo of Catalpa bungeana in the Forbidden City

Catalpa trees have tall and straight branches and light red and elegant flowers. Since ancient times, Catalpa bungeana has been widely planted in palaces and gardens with scenic spots, such as the Forbidden City, Beihai, Summer Palace, University Hall and other tourist attractions and ancient temples in Beijing. There are ancient Catalpa bungeana trees over a hundred years old everywhere, which are vigorous and tall. So how is Catalpa bungeana cultivated? Is there any good way to breed? What should be paid attention to when breeding Catalpa bungeana? Please read with me with questions!

Propagation method of Catalpa bungeana (basic knowledge): The best propagation time: Catalpa bungeana can be propagated in spring and autumn. The planting time in spring is from late March to mid-April, and in autumn:165438+1mid-October 65438+early February.

The most suitable soil for growth: Catalpa bungeana likes deep, fertile and moist soil.

Requirements for growth humidity: The growth humidity of Catalpa bungeana should be kept at 68-79 {BF}.

Optimum growth temperature: Catalpa bungeana is suitable to grow at the annual average temperature of 10- 15℃.

Optimum growth light: Catalpa bungeana likes a sunny growth environment.

Matters needing attention in Catalpa bungeana cultivation: water and fertilizer management;

Catalpa bungeana has strict requirements on water content, which should be paid attention to in daily maintenance. Take the saplings planted in spring as an example. Besides the first three times, water should be poured twice in May, June, September and 65438+1October. July and August are periods of abundant rainfall. You don't need to water them if the weather is not too dry. At the beginning of 65438+February, it is necessary to pour enough antifreeze water, and the next spring. Water the green water in time at the beginning of the month, twice in April, May, June, September and 10. Antifreeze water should be poured in early February of 65438+,and it can be poured in the third year according to the method of the second year. After the fourth year, natural precipitation will increase reliably except for greening water and antifreeze water. However, when the weather is too dry, it is still necessary to water when there is little precipitation, and some street trees that have grown for many years should also be watered when it is dry, which is beneficial to the growth and life extension of plants.

Catalpa bungeana likes fertilizer, except applying sufficient base fertilizer when planting; Should also be 1 combined with frozen water to apply some fermented sesame paste residue or cow dung at the end of autumn every year, and apply some urea to the plants at the beginning of May, which can make the plants flourish; Accelerate growth and apply some phosphorus and potassium fertilizers in late July; It can effectively improve the lignification degree of plant branches and is beneficial to the safe overwintering of plants.

Pruning points:

Catalpa bungeana is resistant to pruning and has strong germination ability. Catalpa bungeana is generally cut off before planting, and the dry height can be determined according to the use requirements or design requirements. When the new branches grow to about 30 cm in spring, three or four branches that are robust, evenly distributed and not on the same track are selected as the main branches, and all other new branches are cut off. In the growing period, the trunk will sprout some buds, which should be erased in time to prevent excessive consumption of nutrients.

The new branches of Catalpa bungeana grew rapidly, reaching 80 cm to 120 cm that year. After defoliation in late autumn, cut the selected main branches into short, medium and long branches, leaving 40 cm to 60 cm, and ensure that there are external buds. In the process of cultivation and management, some people often leave the main branches to grow without pruning. As a result, the crown of Catalpa bungeana is narrow, unopened, unsightly and the shade area is small. Therefore, it is a favorable measure to enlarge the crown of Catalpa bungeana by cutting off the middle and short branches and choosing the outer buds. At the end of the next spring, the main branches were screened with new branches, and two new branches were left on each main branch as side branches. The selected branches should grow vigorously, not cross each other, and all other branches should be thinned out. After the leaves fall in late autumn, these branches should be cut short and medium, and the outer buds should be kept.

After gradual pruning, the basic tree shape of Catalpa bungeana was formed. In the future maintenance, only drooping branches, cross branches, over-dense branches, diseased branches and dead branches need to be thinned.

Breeding point:

Catalpa bungeana can be propagated by sowing, burying roots, cutting and grafting, and the common methods are burying roots and grafting.

Buried root propagation

At the end of March, the root strips with the thickness of 1cm ~ 2cm and the length of 12cm ~ 20cm were selected from the robust catalpa bungeana trees with DBH greater than 15 cm, and the incision should be smooth. Obliquely buried in the soil, the plant spacing is 20cm× 20cm, with the big head up and the small head down. When burying roots, we should pay attention to compacting the soil so that the roots can be closely combined with the soil. The upper end of the root is slightly lower than the ground by 2 cm. After burying, tread lightly and then water.

Horizontal buried propagation

The flat burying method is to lay the roots flat in the groove, fill the soil and step on it, and the spacing between plants is 30 cm ×30 cm. It can germinate in about 20 days after burying the roots. When the seedling height is about 15 cm, pull out the tillers in time, leaving only one strong branch per root. Applying urea once at the beginning of May with a dosage of 50 kg/mu can promote the growth of seedlings. In mid-June, phosphorus and potassium compound fertilizer was applied again to improve the lignification degree of seedlings. In the second year, seedlings were transplanted with a row spacing of 60 cm ×60 cm.

propagation by grafting

Catalpa bungeana was used as seedling and rootstock to graft Catalpa bungeana. In late March, the seeds of Catalpa bungeana were sown by drilling, and urea was applied once a month after the seedlings came out, with the dosage of 50 kg per mu to promote the growth of the seedlings. In the middle of April of the following year, grafting was carried out by bud grafting. After grafting, the bud grafting was covered with plastic bags to keep moisture. After the bud grafting survived, the plastic bags were removed.

Pest control:

Common pests

Bug, paulownia tortoise shell, moth, white-striped moth, Chrysopa chrysalis, Bombyx Batryticatus, Dictyophora, Cicadellidae, etc.

If there are permanent bedbugs; Spraying 20 {BF} concentrated soluble solvent 3000 times in adult and nymph stages can kill it.

The occurrence of paulownia tortoise shell can be killed by spraying 3,000 times of 3 {BF} hypertonic fenoxycarb EC in larval stage.

When moths occur; Spraying 3000 times of solvent with 20 {BF} concentrated solution can kill it.

Spraying 48 {BF} Bacillus thuringiensis at the larval stage of Noctuidae and killing the 3rd instar larvae with 7000 times of 20 {BF} diflubenzuron suspension can kill the Noctuidae.

When the frost moth occurs seriously, it can be killed by spraying 500 times Bt emulsion;

If it happens, it can be controlled by spraying 10 {BF} imidacloprid wettable powder 1000 times. The harm to Cicadellidae can be caused by spraying 1000 times of 25 {BF} chlorpyrifos wettable powder or 3500 times of 48 {BF} leshi emulsifiable concentrate at the nymph stage.

Common diseases

Including Catalpa bungeana anthracnose and Catalpa bungeana root nodule nematodiasis.

Catalpa bungeana anthracnose mainly harms the leaves and shoots of Catalpa bungeana, which is easy to occur in high temperature and high humidity period and poor ventilation conditions. After illness, the leaves withered and fell off. Attention should be paid to ventilation and light transmission, water and fertilizer management should be strengthened, and plant disease resistance should be improved. If it happens, spraying 500 times of 80 {BF} anthrax Fu Mei wettable powder once every seven days and spraying it continuously for three or four times can effectively control the disease.

Root-knot nematode disease of Catalpa bungeana mainly harms the root system of Catalpa bungeana. Taproot, lateral root and small root can all be infected. After the onset, some tumors grew on the root system, and then the root system rotted, leading to the gradual death of the plant. This disease is stubborn. Quarantine should be strengthened before planting to prevent the introduction of diseased seedlings. If it happens, 10 {BF} aniline phosphorus powder (3 kg to 4 kg per mu) or 98 {BF} mianlong micropowder (5 kg to 6 kg per mu) can be applied to the roots for control.

Expanding knowledge-the use of catalpa bungeana: industrial use