Prevention and Control of Diseases and insect pests of Catalpa

Anthracnose disease control

When Catalpa is infected with anthracnose, its leaves and shoots will be very harmful, especially in the case of high temperature, high humidity and poor ventilation. If infected, the leaves of Catalpa will fall off after wilting.

Therefore, for anthracnose, maintain environmental ventilation and light transmission, maintain a good supply of water and fertilizer, this operation can improve the disease resistance of catalpa trees, but if it is still infected, disease prevention agents should be sprayed once a week. 3-4 consecutive spraying of the disease can be effectively controlled.

Control of root nodule nematode disease

The root system of catalpa tree will be damaged by nodule nematode disease, and the main root, lateral root and small root will be invaded. This disease will produce nodules in the root of catalpa tree, and then the root system will slowly rot and eventually die.

Because the disease is stubborn, quarantine should be strengthened before planting so as not to bring in the diseased plant. once it occurs, 10% grams of phosphorus powder or 98% micronutrient powder can be applied to the root.

The above is about the introduction of disease and pest control of catalpa tree, next let's take a look at the value of catalpa tree!

Cultivation and pest control techniques of Catalpa chinensis

Liriodendron, also known as Juglans mandshurica, is a deciduous tree belonging to the catalpa of the family Liriodendron, which is mainly produced in the Yellow River and Yangtze River basins in China, and is also distributed in North China and Zhejiang and Anhui provinces. Catalpa tree trunk is tall and straight, growing rapidly, suitable for shade trees, street trees, can also be used to decorate lawns, rockery, is a good material for landscaping. The cultivation and management techniques are introduced as follows, for reference only. Morphological characteristics and ecological habits of catalpa up to 35 meters high, trunk tall and straight, crown is Obovate, bark gray or dark brown, shallow longitudinal crack. There are tuberous protuberances on the trunk of the old tree, and the young branches are grayish green and glabrous. Leaves opposite or verticillate, triangular-ovate or long-ovate-elliptic, apex acuminate, base truncate to broadly cuneate or heart-shaped, 5 cm to 17 cm long, entire, abaxially with purple glandular spots. Racemes terminal, with 3 to 12 flowers, Corolla light pink with purple spots. The capsule is 25 cm to 45 cm long, about 5 mm in diameter, with flattened seeds and long white hairs at both ends. Flowering from April to May and fruiting from September to October. Liriodendron likes light, seedlings are slightly tolerant to shade, like warm and humid climate, but not resistant to severe cold. Catalpa is neither drought-resistant nor water-resistant, nor barren. It likes moist, fertile, permeable sandy loam, can tolerate mild saline-alkali soil, and can grow normally in mild saline-alkali soil with pH8.8 and 0.15% salt content. It has strong resistance to sulfur dioxide and chlorine and strong dust retention ability. Planting method planting Juglans mandshurica in landscaping can be carried out in both spring and autumn. The planting time is from late March to mid-April in spring and from mid-November to early December in autumn. Before planting, planting holes should be dug according to the requirements. The planting holes should be not less than 1.2 meters × 1.2 meters, and the depth is not less than 80 centimeters. The topsoil and subsoil should be stacked separately. If the soil quality does not meet the requirements, the soil should be changed. Planted catalpa trees with DBH less than 10 cm can be planted with bare roots, and seedlings with more than 10 cm had better be planted with soil balls, which can maintain a high survival rate. When planting Juglans mandshurica trees, we must be careful not to plant too deep, which can easily lead to muggy buds, even seedlings planted in autumn. When watering the spring water in the early spring of the second year, the mound should also be removed, which is conducive to plant germination. Generally speaking, when planting bare-root seedlings, the fill can be 2 cm to 3 cm higher than the original soil marks, and the seedlings with soil balls should be flush with the original soil balls. Catalpa trees like fertilizer, should be planted with some rotten fermented circle fertilizer as the base fertilizer, the base fertilizer should be mixed well with the planting soil, it is easy to burn roots. Water should be watered immediately when planting in spring, two water after three days, and three water after five days. Autumn planting should be based on the planting time to determine the watering times. If it is planted in the middle of November, it can be watered twice, that is, it can be watered immediately after planting and two water after seven days; if it is planted in early December, it can be watered once. After planting, brackets should be set up in time for larger seedlings to prevent wind blowing or artificial shaking. The requirement of water and fertilizer management of catalpa chinensis is relatively strict, which should be paid attention to in daily maintenance. Taking the seedlings planted in spring as an example, in addition to watering the first three waters, they should also be watered once or twice in May, June, September and October. July and August are periods of abundant precipitation. If they are not too dry, they can not be watered, and they should be fully watered in early December. In the following spring, they should be watered back in time in early March, and watered once or twice in April, May, June, September and October, and anti-freezing water in early December. The third year can be watered according to the method of the second year, and after the fourth year, in addition to watering green water and anti-freezing water, reliable natural precipitation grows, but when the weather is too dry, it should still be watered when the precipitation is low, and some street trees that have grown for many years should also be watered during drought. this is conducive to plant growth and prolong life. Liriodendron likes fertilizer. In addition to applying sufficient basic fertilizer at the time of planting, some rotten and fermented sesame sauce dregs or cow and horse manure should be applied in combination with frozen water at the end of autumn every year. Some urea can be applied to the plant at the beginning of May, which can make the plant grow luxuriantly and accelerate its growth. The application of some phosphorus and potassium fertilizer in late July can effectively improve the Lignification degree of plant branches and be conducive to the safe overwintering of plants. Reshaping and pruning catalpa trees are resistant to pruning and have strong sprouting ability. Catalpa trees are generally cut off before planting, and the dry height can be determined according to the requirements of use or design. In spring, when the new branches grow to about 30 cm, among the branches close to the top, three or four branches with strong growth, uniform distribution and not on the same track are selected as the main branches, and the rest of the new branches are all cut off. During the growing period, the trunk will also sprout some buds, which should be erased in time to prevent excessive nutrient consumption. The new branches of the catalpa tree grow faster, and they can grow to 80 cm to 120 cm in the same year. After the leaves fall at the end of autumn, truncate the selected main branches and retain 40 cm to 60 cm. Be sure to leave outer buds. In the process of cultivation and management, some people often do not truncate the main branch and allow it to grow. as a result, the crown of catalpa tree is narrow and does not open, which is not beautiful and the shade area is small. Therefore, the truncation of the main branch and the selection of outer buds are favorable measures to expand the crown of Catalpa chinensis. At the end of the next spring, the new twigs on the main branches were screened, and one or two new branches were retained on each main branch as side branches. The selected branches should grow strong and can not be staggered with each other, and all the other branches should be removed. After the leaves fall at the end of autumn, these branches should be cut short and medium, and the outer buds should also be retained. After the above pruning, the basic tree shape of catalpa tree is formed, in the future maintenance, only need to remove drooping branches, cross branches, over-dense branches, disease and insect branches, dry and withered branches. Pest control 1. Common pests such as Perth bug, paulownia tortoise shell, moth, white kidney armyworm, frost moth, ginkgo silkworm moth, catalpa beetle wild borer, big green leafhopper and so on. If the bug bug occurs, it can be killed by spraying 3000 times of 20% Kangfuduo solvent in the adult and nymph stage, 3000 times of 3% hyperosmotic phenoxyvir EC in the larval stage of paulownia tortoise shell, and 3000 times of 20% Kangfuduo solvent in its larval stage. When Spodoptera litura occurs, 48% Bacillus thuringiensis can be sprayed in its larval stage, and 7000 times of 20% diflubenzuron suspension can be used to kill pre-3rd instar larvae; when frost moth occurs seriously, 1000 times of Bt emulsion can be sprayed to control the wild borer, Chilo suppressalis If the green leafhopper is harmful, it can be sprayed with 1000 times of 25% buprofezin wettable particles or 48% of 3500 times of Lesbon EC in the nymph stage. two。 Common diseases include anthracnose of Juglans mandshurica and root nodule nematode disease of catalpa. The anthracnose of Juglans mandshurica mainly harms the leaves and shoots of Liriodendron chinensis, and it is easy to occur in the period of high temperature and humidity and poor ventilation. After the disease, the leaves wilted and fell off. In the process of maintenance, we should pay attention to ventilation and light transmission, strengthen the management of water and fertilizer, and improve the disease resistance of the plant. If it occurs, it can be sprayed with 80% anthrax Fumei wettable granule 500 times for prevention and control, once every seven days. Three to four consecutive sprays can effectively control the disease. Liriodendron root nodule nematode disease mainly harms the root system of catalpa tree, the main root, lateral root and small root can be infected, after the disease, some nodules are planted on the root system, and then the root rot, resulting in the gradual death of the plant. The disease is relatively stubborn, and quarantine should be strengthened before planting to prevent the introduction of diseased seedlings. If it occurs, 10% line phosphorus powder (3 kg to 4 kg per mu) or 98% micronized powder (5 kg to 6 kg per mu) can be applied to the roots for prevention and control. The propagation methods of catalpa chinensis can adopt sowing method, root burying method, cutting method and grafting method, and the common methods are root burying method and grafting method. 1. Root burying method in late March, in the strong growth, DBH more than 15 cm on the selection of 1 cm to 2 cm thick root strips, 12 cm to 20 cm long, the cut should be smooth. Obliquely buried in the soil, the plant row spacing is 20 cm × 20 cm, big head up and small head down, burying the root should pay attention to compacting the soil, so that the root is closely combined with the soil. The upper end of the root is slightly 2 cm below the ground. After burying it, step on it gently, and then water it thoroughly. The flat burying method is to put the root strips flat in the groove and step on the soil with a row spacing of 30 cm × 30 cm. It can sprout about 20 days after burying roots, and the tillers can be removed in time when the seedling is about 15 cm high, and only one strong branch is retained for each root. The application of urea at the beginning of May with the dosage of 50 kg / mu could accelerate the growth of seedlings. In the middle of June, phosphorus and potassium compound fertilizer was applied again to improve the Lignification degree of seedlings. The seedlings were transplanted in the second year, and the row spacing was 60 cm × 60 cm. two。 Grafting method grafted catalpa trees were used as seedlings as rootstocks. The seeds of catalpa tree were sown by strip sowing method in late March, and urea was applied once after the seedlings came out for one month, the dosage was 50 kg per mu to accelerate the growth of seedlings, and in the middle of April of the following year, grafting was carried out by bud grafting. After grafting, the grafted buds were covered with plastic bags for moisturizing, and the plastic bags were removed after the buds survived.

Prevention and control of plant diseases and insect pests

First, rational use of chemical control, control the spread of diseases and insect pests chemical control is to use the toxicity of chemicals to control diseases and insect pests, in order to maintain the party growth of garden flowers and trees, many important diseases and insect pests can often be effectively controlled if drugs can be used in a timely and rational manner. Chemical control also has the characteristic of quick effect. When some diseases and insect pests are about to occur or have already occurred, timely chemical control can often be used to control the spread of diseases and insect pests. In addition, chemical control has a wide range of adaptation, less affected by regional and seasonal effects, and can be used in different types of areas and different seasons. However, the long-term extensive use of pesticides also brings some adverse consequences, mainly in the pollution of the environment, harm to natural enemies, and easy to cause drug resistance of diseases and insect pests.

Second, give full play to the advantages of comprehensive control and improve the effect of comprehensive prevention and control based on the principle of "prevention first and comprehensive control", and make rational use of cultivation, chemical, biological, physical and other effective ecological means. keep diseases and insect pests to a minimum so as not to cause harm. Its advantages are:

1. Coordinate measures to reduce contradictions. If chemical control and biological control are coordinated, it can not only kill diseases and insect pests, but also give full play to the role of natural enemies. Such as the use of internal insecticides, smear stem, stem and root watering, early control of aphids, red spiders, shell insects. The selection of natural enemies with strong resistance to pesticides and the application of selective agents with less killing natural enemies is the way to avoid or reduce contradictions.

2. Strive to cure both sides and simplify the measures. In nature, a variety of diseases and insect pests often occur at the same time, respectively control, resulting in repetition. Take a kind of dominant diseases and insect pests as the object, grasp the key of plant development and the favorable opportunity of pest control, concentrate on the use of drugs, and treat others at the same time. According to the occurrence of diseases and insect pests at that time and in the local area, we can seize the favorable opportunity and adopt targeted measures such as releasing natural enemies, using bacteria and chemicals to achieve the purpose of simultaneous treatment.

3. Learn from each other's strong points to offset their weaknesses and complement each other. The environmental factors that constitute the occurrence of diseases and insect pests and the reasons that affect their occurrence are various, and the prevention and control measures also have their own advantages and limitations. Therefore, it is necessary to learn from each other and improve the effect. For example, when controlling "seed flies" of underground diseases and insects, the damage can be basically controlled by paying attention to the combination of fertilization and chemical killing of adults.

Third, to establish a garden plant protection system to promote the development of ecological gardens, garden plants and crops, trees have a lot in common and internal relations, but there are great differences. The city is the carrier of garden diseases and insect pests, and the city is a man-made environment, which has a qualitative change compared with the natural environment of agriculture and forestry. For example, the temperature is on the high side, the relative humidity decreases, the soil structure is complex; the waste gas, waste water and waste produced by the city pollute the atmosphere, water source and soil of the city, and the ecological environment deteriorates; the city scale is large, the building density is large, and hinders the circulation and exchange of the atmosphere. It is easy to produce heat island effect, which will inevitably affect the distribution and growth of garden plant populations, and accordingly affect the occurrence and development of diseases and insect pests. According to the characteristics of the urban environment, a scientific and reasonable artificial plant community is established by making use of the relationship between plant communities, so that they can promote, restrict and reproduce together, form a stable ecological environment and control the occurrence of disastrous diseases and insect pests. The establishment of an ecologically sound and stable garden plant community, that is, the ecological garden system, is conducive to the prevention and control of diseases and insect pests and can achieve effective control without or with less medication. When diseases and insect pests exceed the allowable range of control, it is necessary to control them with drugs in time. Ecological garden prevention and control embodies the principle of giving priority to prevention and control, supplemented by treatment, it can not only produce huge eco-environmental benefits, but also receive great economic benefits.

Fourth, to establish a comprehensive control system to ensure the effective prevention and control of garden diseases and insect pests. An excellent planning and design of garden green space should not only fully show the aesthetic and recreational functions of the garden, but also meet the conditions needed for the establishment of ecologically stable plant communities. The key is to avoid plant species being too simple, to avoid selecting tree and grass species that are susceptible to diseases and insects and fragile ecological functions, and to create a good ecological environment for plant growth. Urban road greening should also adhere to the principle of multiple tree species, and emphasis should be placed on the selection of tree species in each road, mainly native tree species with strong adaptability and resistance to diseases and insect pests and exotic tree species that have been cultivated and domesticated for a long time and adapted to the region. Taking Huaibei area as an example, it is appropriate to select tree species with strong resistance to diseases and insect pests, such as catalpa and ginkgo biloba. Maintenance and management is also an important measure to prevent the occurrence of diseases and insect pests. Timely fertilization, pruning, watering and maintenance should be carried out to ensure the healthy growth of trees and seedlings. A strong plant is more resistant to diseases and insect pests than a thin plant. For example, if Haitong grows in places with poor ventilation and insufficient sunlight, it is easy to be harmed by cotton blowing scale; the site environment has a great impact on trees, and there are few scale insects when cultivated as disease-free trees in the green space of the park, but they are harmed by a scale bug when they are planted on the street as a street tree. Therefore, we should pay attention to study the site environment, improve the site conditions, and create a favorable environment to inhibit the occurrence of diseases and insect pests and promote the growth of plant communities. From the planning and design of garden and green space to the transformation of site environment, scientific cultivation, rational use of conservation techniques, strengthening preventive measures, supplemented by chemical and biological measures, a scientific comprehensive garden control system should be established. it must make the prevention and control of garden diseases and insect pests get twice the result with half the effort, and should also be applied as an important measure in garden work.