Imperative Development of Pollution-Free Protection of Landscape Plants

  • offcial website of Beijing Expo 2019  2017-Sep-14 15:30:00

Landscape plants are part of the urban ecosystem. Their main function is protecting and improving urban environment, providing the city with greenery, and adjusting the microclimate of the city. Generally, urban greenery coverage should reach more than 30% in order to meet the needs of normal human life. Landscape plant protection is one of the technical measures that serve the greening of the city.

The direction of landscape plant protection is “prevention first and comprehensive prevention and control”. It should be developed towards the goal of pollution-free urban landscape, ensuring the safe, effective and economical control of disease and pests, the normal growth of landscape plants and their greening function. The landscape ecosystem and the work of prevention and control of disease and pests will be protected and promoted to create a clean and decent urban environment for the people.

The current plant protection across China is mainly chemical prevention and protection. Because trees are tall in cities, we can only use big truck and high-pressure spray to make sure the pesticide is evenly spread on each part of the tree. But the result is that only a small quantity of the pesticide is absorbed by the plants and eaten by the insects. Most of it is lost in the surrounding environment. Therefore, it is imperative to develop pollution-free garden plant protection.

We need to establish quality standards for technical operation of landscape plant disease and pest prevention and control. Standards and requirements of drug spraying, mite-killers and pesticides in the forms of granules used on roots, liquid used in irrigation, high-pressure spray, and ointment used on trees after peeling, as well as the practice of killing pests with smoke. The goal will be precise use of pesticide and targeted elimination of pests.

As the undertaking of urban landscaping develops, domestic and international communication increases, and the system of circulation of goods advances, the import and export of nursery stock has become a common thing. But the risk of introducing critical foreign disease and pests has also increased. Many cities try hard to hold horticultural expositions but few of them consider inspection and quarantine. In recent years, many foreign invasion cases related to harmful creatures have happened, resulting in serious lost, like the invasion of American white moths, pine wood nematodes, hemiberlesia pitysophila, etc. The original disease and pest-ridden areas and areas influenced in China are expanding rapidly, involving anoplophora glabripennis, anoplophora nobilis, etc. Therefore, we still have much to do in terms of strengthening inspection and quarantine of plants, which can fundamentally prevent the spreading of disease and pests. Departments of garden in the city should set up the authority in charge of inspection and quarantine of urban landscape plants, and the general survey of disease and pests. When importing nursery stock from foreign cities, provinces and countries, the authority should point out the object of inspection and quarantine, and ensure review and acceptance based on qualifications for imported nursery stock. When exporting nursery stock, personnel in charge of inspection and quarantine should conduct the primary field test and export the plants only with authorization of plant inspection and quarantine authority.

Humans should learn from nature. In planning and design, we should configure the plant populations with the goal of achieving multiple plant communities and avoiding the fatal disease and pests from planting a single species. For example, cronartinm ribicola hurts pure woods harder than hybrid woods.

In landscape design, we should consider proper layout, and trees that can worsen diseases and pests should be separated. For example, if locust tree and paulownia are planted together, there will be an outburst of stink-bugs and eulecanium corni. Junipers should be separated from crabapple trees and apple tress to avoid gymnosporangium yamadai.

Biological prevention and control will be the future of landscape plant protection. This means using organisms or biological metabolites to control pests. In other words, we are using beneficial beasts, birds, insects, mites, bacteria, fungus, virus and hormones to eliminate pests. Biological prevention and control have many advantages. They can protect the environment without pollution, pests are unable to develop resistance, and are safe for humans, animals and plants. Used properly, it can be economical and effective, saving time and effort. Recently, the landscape authority of Tianjin set free over 200 million chouioia cunea Yang, which can protect 50,000 trees from American white moths.

But when push comes to shove, besides strengthening disease and pest detection and warning, we should also seize the opportunity and apply chemical prevention and control before these overeating pests suddenly attack.

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