So how to prevent and reduce wind damage?
1. Select wind-resistant tree species. In planting design, trees with strong wind resistance, such as weeping willows, are selected at the tuyere and air duct, and tree species with deep roots, short stems and sparse and tough branches and leaves are selected. Don't choose fast-growing trees with dense branches and leaves and some trees prone to pests.
2, pay attention to the quality of seedlings and planting techniques. When transplanting seedlings, especially big trees, if the roots are small, the trees are vulnerable to wind damage because of their large bodies. So when transplanting a big tree, you must erect a pillar to prevent the tree from blowing crooked. When planting in windy areas, the pit should be appropriately expanded. If planted in a small pit, the tree will be easily damaged by the wind, because its roots are not stretched, its development is not good, and its center of gravity is unstable. For fallen trees damaged by strong winds, they should be righted in time, and the soil should be made into steamed buns, some branches should be trimmed and pillars should be erected. The split branches should be tied tightly at the base to promote their healing, and strengthen the management of fertilizer and water to promote the recovery of tree potential.
[26] How to use plant ash to control flower diseases and insect pests?
Plant ash can not only supplement potassium and other nutrients for flowers, but also play a very good role in preventing and controlling flower diseases and insect pests.
Prevention and control of leaf blight: plant ash, tea cake, sulfur powder and lime are 65,438+0 kg, 65,438+0.5 kg respectively, which are mashed into powder and mixed evenly, and each pot of flowers prone to leaf blight is applied with 65,438+0.5 g ~ 2.5 g.
Control of leaf spot disease: mix 3kg of plant ash and quicklime powder 1kg, then spread, 40g ~ 60g per pot, or sieve and spray powder, or spread plant ash alone.
Control of root rot: plant ash has a good control effect on flower root rot. The specific operation method is to dig up the soil at the root first and remove the soil around the rotten root. Scrape the diseased root skin, and apply 0.5 ~ 1 kg plant ash to each plant, cover the root and cover it with soil.
Prevention and control of powdery mildew: For flowers with powdery mildew, root soil with a depth of 5 ~ 10cm can be scraped off the trunk, and each plant should be covered with 0.5 ~ 3kg of plant ash and thin soil in plant ash.
Prevention and control of seedling diseases: flower nurseries are prone to damping-off and anthracnose at seedling stage. When humidity is high and temperature is low, seedling diseases are serious, and a large number of seedlings often die. Plant ash can be used to spread along the ridge, and the dosage per mu is 20 to 25 kilograms.
Prevention and control of aphids: plant ash is crushed and sieved, and plant ash is sprayed on aphids when the dew is still wet in the morning (or sprayed with water first), or gauze can be used to shake well, and then sprayed two or three times every three to five days.
Prevention and control of root maggots: when root maggots harm flowers at seedling stage, if the roots are irrigated with pesticides to prevent and control drug damage, 30-40 kilograms of plant ash can be applied to Miao Moody. The application method is to spread plant ash evenly on the border at seedling stage, and then turn over the soil and hoe it evenly, so that the plant ash and the soil are fully mixed. Plant ash can also be planted in ditches before sowing or planting.
Prevention and control of underground pests: Miao Di, a bulbous flower, is often harmed by underground pests such as grubs in the process of seedling raising. Using plant ash as base fertilizer for prevention and control, or covering seed blocks with plant ash, can obviously reduce the harm.
New weeding method
The wide application of chemical herbicides has played a great role in controlling weeds. However, the large use of herbicides will destroy the ecological balance and lead to environmental pollution. In recent years, a large number of research results show that some weeds can be effectively controlled by various methods, and they are safe and pollution-free, which is a new way to control weeds.
American scientists have developed a herbicide, the main component of which is aminolevulinic acid, which has a small dosage, good effect, no harm to crops, no harm to people and animals and convenient use. Spraying before dusk will be absorbed by weeds, which will produce harmful substances under the action of light, destroy the cell membrane of weeds and make them flow out of juice, and the weeds will turn white and die within 4 hours.
Scientists at the American Agricultural Research Center have found that some bacteria that infect the roots of weeds such as Xanthium sibiricum and Datura stramonium can play a weeding role. Bacteria multiply in cracks in weed cell walls. These bacteria decompose the cell wall of weed roots or transfer toxins to weed leaves, thus reducing the synthesis of chlorophyll. In addition, they also interfere with the balance of weed hormones, making weeds more sensitive to drought and disease. Experts also found that some root bacteria can rot weed seeds. Scientists screened out these bacteria, propagated them in large quantities and sprayed them on the fields. After 7 days to 10, all the weeds died.
The United States has successfully developed a plastic rope that can absorb herbicides and release herbicides slowly. Filling this plastic rope into the joints and cracks of airport runways can prevent these places from growing and spreading weeds for many years, thus protecting asphalt and concrete pavements and avoiding various accidents caused by the spread and growth of weeds.
[27] How far can chemical control go?
Eliminating a certain forest pest has always been the traditional thinking mode and working method of forest pest control. Chemical control is the most important means to control forest pests and rodents, and the total amount of pesticides is gradually increasing every year. The annual consumption of chemical pesticides in the world is about 3 million tons, and the consumption of forestry drugs in China is about 30 thousand tons. At that time, the use of chemical pesticides could temporarily control the harm of major pests and diseases and save some economic losses, but it also brought a series of negative effects. This method of killing pests with toxic compounds has been the main strategy of pest control since 1950s. Security issues, ecological issues and economic issues have become the focus of people's thinking today. How far can chemical control go? To truly solve the problem of pests, we must change our concepts and replace "treatment" with "prevention".
Chemical pesticides do not belong to any part of the natural ecosystem, but are artificially imposed. Both theory and practice have proved that they have adverse effects on the sustainability of forestry production. For example, while controlling forest pests such as Dendrolimus punctatus, Cerambycidae and Hyphantria cunea, it killed beneficial natural enemies such as spiders and parasitic bees, stimulated the reproductive ability of these forest pests, caused greater rampant, increased the difficulty and cost of prevention and control, and greatly affected the growth of stands, which would inevitably cause a series of adverse reactions. At present, more than 500 kinds of pests, 150 kinds of pathogens and 100 kinds of weeds have developed resistance to chemical pesticides. The adverse effects of chemical pesticides on the environment have attracted people's attention. For example, Silent Spring has clarified the pollution of chemical pesticides such as DDT. However, due to the underdeveloped social and economic conditions, relatively backward productivity and limited high-tech research and development capabilities in China, it is inevitable that chemical pesticides will be widely used in the short term. However, with the social and economic progress of our country, the improvement of people's living conditions and the awareness of ecological environment protection, more and more people realize the destructive effect of chemical pesticides on people and the natural environment, which has triggered the rise of the concept of sustainable development. China has strengthened the supervision and management of the production, management and use of household drugs, and is gradually banning the production, sale and use of some highly toxic and highly toxic chemical pesticides, and vigorously promoting the use of high-efficiency and low-toxic pesticides, biological pesticides and bionic preparations. Such as Bacillus thuringiensis, diflubenzuron, Beauveria bassiana, abamectin, sterile agent, green Wei Lei, etc. , to ensure forestry production and ecological environment, to ensure the safety of people and animals. The history of chemical pesticide control will end with the voice of environmental protection and the rise of biological control technology. ...
Biological control technology includes releasing natural enemies of various pests, luring insect-eating birds, using biological agents (viruses, bacteria, fungi, actinomycetes and nematodes), physical radiation technology, genetic engineering, insecticidal active substances of animals and plants, sex pheromones, resistant plant varieties and all other biological-based products. At present, the application of these technologies in forestry in China is still quite weak, especially the "reproduction and release" technology of natural enemies of pests, which needs further research and development in the future. These biological products are mainly used to control the rampant spread of pests and diseases in time and effectively at the initial stage of the epidemic, rather than for disaster relief after the epidemic. This is in line with the principle of "forest health care" advocated now. Therefore, changing "chemical defense" into "chemical defense" is in line with the requirements of the development of the times.
To improve the effect of biological control, we must strengthen the work of "monitoring and forecasting", and only by improving the early warning mechanism of pests and diseases can we lay the foundation for scientific control. In recent years, the occurrence area of forest diseases and insect pests in China has exceeded 8 million hectares, and the annual economic loss has reached 5 billion yuan. The reasons for this situation are not only objective reasons such as abnormal climate, but also factors that violate the natural law of forest resources cultivation, and the forest protection policy of "prevention first and comprehensive management" has never been really implemented. If we really want to eliminate the recurrent pests and diseases in the initial stage and master the epidemic dynamics of dangerous pests and diseases, we must do a good job in forecasting and monitoring and be the "eyes and ears" of prevention and control. At present, China has established a national forecasting center and an alien pest inspection center, focusing on the construction of a national center forecasting point, a quarantine information network and a team of forest rangers at the township (forest farm) level, investigating pests and diseases, further establishing and improving the contact reporting system of forest pests, improving the forecasting methods of major forest pests and diseases, and gradually applying aerial monitoring technology to improve the scientific and technological content of monitoring. In addition, strengthen quarantine and completely eliminate alien pests. For some exotic harmful forest diseases and insect pests that are difficult to eliminate for a while, we should have the idea of long-term fighting, make unified planning from the perspective of ecosystem balance, find effective measures to curb them, and realize the benign development of peaceful coexistence between exotic organisms and local organisms.
When forest diseases and insect pests occur, biological control measures will completely replace chemical control measures, and it is not far off.
[28] Advantages and disadvantages of chemical control and biological control
Advantages of chemical control: under certain conditions, it can quickly eliminate pests and reduce insect population density.
Disadvantages of chemical control: long-term use is easy to produce phytotoxicity, make pests and diseases resistant, pollute the environment and kill natural enemies.
Advantages of biological control: less environmental pollution, effective protection of natural enemies and continuous control of disasters.
Disadvantages of biological control: the insecticidal effect is slow, and the purpose of quickly inhibiting insect population can not be achieved when used at high insect population density.
[29] Classification of commonly used pesticides and machinery
Commonly used pesticides can be generally divided into seven categories according to different uses.
1, pesticides are used to control various pests, and some can also kill mites, such as dichlorvos, dimethoate, methamidophos, chlordimeform, pyrethroids and other pesticides. They mainly kill pests by means of stomach poisoning, contact killing, fumigation and internal inhalation.
2. Acaricide is a special agent for controlling mites (that is, red spiders), such as mirex, dicofol and chlorfenapyr. Acaricides are selective and have different control effects on harmful mites at different development stages. Some acaricides have good contact killing effect on eggs and larvae or young mites, but have poor effect on adults.
3. Fungicides are used to prevent and control plant diseases, such as Bordeaux mixture, zineb, carbendazim, fenxiuning, Kewenling and other pesticides. It mainly plays the role of inhibiting the growth of bacteria, protecting crops from infringement and infiltrating into crops to eliminate invasive bacteria. Most fungicides mainly play a protective role to prevent the occurrence and spread of diseases.
4. Herbicides are specially used to control weeds in farmland, such as herbicide diethyl ether, herbicide Dan, fludongling, chlorotoluron and other pesticides. According to its weeding effect, it can be divided into contact herbicide and systemic herbicide. The former can only be used to control annual weeds with seed germination, while the latter can kill perennial weeds. When the concentration of some herbicides is too high, weeds and seedlings will die or cause phytotoxicity to crops.
5. Plant growth regulators are specially used to regulate plant growth and development, such as gibberellin (92o), naphthylacetic acid, chlormequat chloride, ethylene agent and other pesticides. This kind of pesticide has similar effects with plant hormones, which can promote or resist the growth and development of plants to meet the needs of growth.
6. Nematicide is suitable for controlling various nematodes on vegetables, strawberries, tobacco, fruit trees and trees. Nematodes have developed from the original pesticides and fungicides into a pesticide with therapeutic effects. At present, almost all nematicides are soil treatment agents, most of which have the functions of sterilization and killing soil pests, and some also have the function of weeding. According to the chemical structure, it is divided into four categories: halogenated hydrocarbons, dithiocarbamates and organophosphorus.
7. Rodenticide Rodenticide is divided into stomach medicine and fumigant according to the mode of action. According to the source, it can be divided into inorganic rodenticide, organic rodenticide and natural plant rodenticide. According to the function, it can be divided into acute rodenticide (single dose rodenticide) and chronic anticoagulant (multi-dose anticoagulant).
Medical devices are mainly classified according to the scope of use and supporting power.
According to the scope of use is divided into:
1, nursery and forest spraying such as duster, spray sprayer, ultra-low volume sprayer and smoke sprayer.
2, warehouse fumigation such as smoke machine, fumigator, etc.
3, seed disinfection, such as seed soaking machine, seed dressing machine, etc.
4. Trapping and killing in the field, such as black lights and general traps.
According to the matching power classification:
1, manual medicine manual duster, manual seed dressing machine, manual sprayer, manual ultra-low volume sprayer.
2. Mobile medical devices, such as motorized dusters, motorized sprayers, motorized sprayers, electric ultra-low volume sprayers, motorized sprayers, tractor suspension sprayers, airplane sprayers, airplane dusters, airplane ultra-low volume sprayers and motorized seed dressing machines.