Winter Pest and Disease Prevention and Control Techniques and Methods for Flowers and Nursery Stock

  How to prevent and control pests and diseases in flowers and nursery stock in winter? Low winter temperatures can easily cause the above-ground parts of some flowers and nursery stock to freeze and die. Although some will grow again from the roots the following spring, the cultivation and management of flowers and nursery stock in winter still must not be taken lightly. Pest and disease prevention and control measures need to be carried out well to ensure that flowers and nursery stock can grow normally even in cold winter weather. The specific measures are as follows.

  1 Ensure a clean growing environment for flowers and nursery stock

  When the temperature drops below 0 degrees, the branches and leaves of flowers and nursery stock are prone to withering and rotting, breeding bacteria that cause disease in the flowers and nursery stock. Once the weather warms up, these bacteria will harm the flowers and nursery stock. Therefore, after winter arrives, the plant growing environment must be cleaned regularly, and excess plants must be pulled out by the roots and taken out of the garden in a centralized manner to be buried or burned, so as to prevent diseased plant residues carrying bacteria from infecting healthy plants. In addition, while carrying out cleaning work, management personnel must also disinfect themselves to prevent the artificial spread of pests and diseases.

  2 Remove branches, flowers and leaves affected by pests and diseases

  Winter pruning is an important part of flower and nursery stock management, and before the temperature drops, staff must promptly remove branches, flowers and leaves affected by pests and diseases to prevent the occurrence of pests and diseases. Before pruning, staff must fully understand the relevant pruning knowledge for different nursery stock and must master the symptoms of pests and diseases, so as to carry out pest and disease prevention and control as well as pruning management more comprehensively and effectively. Taking kumquat as an example, when root rot occurs in kumquat, yellowing and withering of the branches and leaves can be clearly seen. At this time, all withered branches and leaves must be pruned off, and the soil must be replaced in a timely manner to ensure suitable humidity and effectively prevent the occurrence of pests and diseases.

  3 Turn over and renew the soil

  Before transplanting flowers and nursery stock, the soil must be turned over and renewed, mainly to promptly eliminate pathogens and insect eggs in the soil. If there are too many pests in the soil, the soil must be replaced with new soil, and before replacement, charcoal ash must be used to disinfect the soil and supplement nutrients. Of course, this method is mainly suitable for small-scale flower and nursery stock cultivation. For nursery stock cultivation bases and natural forests with larger scale and a wider area, after the soil is turned over, birds and insects will eat the pests turned up to the surface. After that, staff must clean the soil once more and then turn it over again, turning the remaining pests and insect eggs underground. Because these pests and insect eggs lack sufficient air supply, they will die naturally.

  4 Apply protective liquid to branches and trunks

  After winter arrives, in order to prevent flowers and nursery stock from being affected by low temperatures and harmed by pests and diseases, lime and water can be mixed into a protective liquid and applied to the branches and trunks of flowers and nursery stock, which can provide a certain protective effect. At the same time, when preparing the protective liquid, attention must be paid to the details of handling the lime, and there must be no lumps in the protective liquid. When carrying out the application, protective equipment (such as plastic gloves) must be worn, because lime and water produce a highly exothermic chemical reaction when they come into contact, and wearing protective equipment can prevent burns.

  5 Spray or irrigate with pollution-free liquid medicine

  When preventing and controlling pests and diseases in flowers and nursery stock, suitable pollution-free liquid medicines should be selected for spraying or irrigation according to different seasons, and the insecticides suitable for different flowers and nursery stock also differ. For example, for kumquat pest control, the liquid is prepared by mixing monothiophosphate with water at a ratio of 1:800 to make an insecticidal liquid, while for magnolia the insecticidal liquid must be prepared by mixing phosmet emulsifiable concentrate with water at a ratio of 1:1 000.

Winter Pest and Disease Prevention and Control for Flowers and Nursery Stock

        As the temperature gradually decreases, most flower and nursery stock pests and diseases will enter an overwintering (or dormant) state in various ways. During this period, various pests and diseases are basically inactive and have little mobility, making it a good season for pest and disease control. Practice has proved that the effectiveness of winter control is directly related to the occurrence of pests and diseases the following year. If winter control measures are effective, the occurrence and harm of pests and diseases in the coming year can be greatly reduced, achieving twice the result with half the effort.

        I. Clean the nursery

        The pathogens (fungi) or overwintering eggs of most flower and nursery stock pests and diseases overwinter in dead branches, fallen leaves or weeds in the nursery, and come out to become active again when conditions are suitable the following year. Therefore, thoroughly removing and destroying dead branches, fallen leaves and weeds in the nursery in winter and improving sanitation can greatly reduce various sources of pests and diseases. This has a significant effect on controlling anthracnose, powdery mildew, rust, red spiders and moths on flowers and trees such as Chinese rose, rose, chrysanthemum, crabapple and willow.

        II. Prune off pest- and disease-carrying branches and leaves

        Winter pruning is one of the important links in nursery management. In conjunction with winter pruning, focus on pruning off pest- and disease-carrying branches and leaves, such as insect eggs on flowers and trees like Chinese rose and rose, and scale insects on poplar, willow and flowering shrubs. The pruned pest- and disease-carrying branches and leaves must be cleaned up promptly and transported out of the nursery for centralized destruction.

        III. Winter plowing and deep turning

        Winter plowing and deep turning can cause mechanical damage to the larvae, pupae and eggs of underground pests lurking in the soil, such as white grubs, cutworms and mole crickets. After being exposed on the surface, they can also be pecked and eaten by natural enemies such as birds, and when necessary, manual capture and killing can also be adopted. In addition, deep turning can bury pathogens from the soil surface into deep soil layers, while pathogens in deep soil layers are turned up to the surface, destroying the suitable living environment for pests and diseases and effectively controlling their occurrence.

        IV. Whitewashing for protection

        Whitewashing branches and trunks can not only effectively prevent freezing damage to flowers and trees in winter and improve their disease resistance, but can also destroy the overwintering sites of pests and diseases, playing the dual role of both freeze prevention and insect killing. It is especially effective against mites and scale insects that overwinter in the bark. Special attention must be paid to fully slaking quicklime, otherwise applying it to the branches and trunks of flowers and trees can easily cause burns.

        V. Chemical control

        Because various pests and diseases are mostly in a dormant state in winter, winter chemical control measures can be adopted for those pests and diseases that are difficult to control during their occurrence season. For example, spraying 50-100 times diluted mineral oil emulsion can control scale insects, and spraying 1% Bordeaux mixture 2-3 times in late winter can achieve good control of many diseases such as pear rust and Chinese rose black spot.

Winter Pest and Disease Prevention and Control for Flowers and Nursery Stock

As the temperature gradually decreases, most pests and diseases infecting flowers and nursery stock will enter an overwintering dormant state in various ways. During this period, various pests and diseases are basically inactive or have very little mobility, making it a favorable time for control. Practice has proved that the effectiveness of winter control is directly related to the occurrence of pests and diseases the following year. If measures are effective, the occurrence and harm of pests and diseases in the coming year can be greatly reduced. At the same time, the use of chemical pesticides can also be reduced to the greatest extent.

Clean the nursery: The pathogens or overwintering eggs of most flower and nursery stock pests and diseases overwinter in dead branches, fallen leaves or weeds in the nursery, and come out to become active again when conditions are suitable the following year. Therefore, thoroughly removing and destroying dead branches, fallen leaves and weeds in the nursery in winter and improving sanitation can greatly reduce various sources of pests and diseases. This has a significant effect on controlling anthracnose, powdery mildew, rust, red spiders and moths on flowers and trees such as Chinese rose, rose, chrysanthemum, crabapple and willow.

Prune off pest- and disease-carrying branches and leaves: Winter pruning is one of the important links in nursery management. In conjunction with winter pruning, focus on pruning off pest- and disease-carrying branches and leaves, such as insect eggs on flowers and trees like Chinese rose and rose, and scale insects on poplar, willow and flowering shrubs. The pruned pest- and disease-carrying branches and leaves must be cleaned up promptly and transported out of the nursery for centralized destruction.

Winter plowing and deep turning: Winter plowing and deep turning can cause mechanical damage to the larvae, pupae and eggs of underground pests lurking in the soil, such as white grubs, cutworms and mole crickets. After being exposed on the surface, they can also be pecked and eaten by natural enemies such as birds, and when necessary, manual capture and killing can also be adopted. In addition, deep turning can bury pathogens from the soil surface into deep soil layers, while pathogens in deep soil layers are turned up to the surface, destroying the suitable living environment for pests and diseases and effectively controlling their occurrence.

Whitewash and protect branches and trunks: Whitewashing can not only effectively prevent freezing damage to flowers and trees in winter and improve their disease resistance, but can also destroy the overwintering sites of pests and diseases, playing the dual role of both freeze prevention and insect killing. It is especially effective against mites, scale insects and others that overwinter in the bark. Special attention must be paid to fully slaking quicklime, otherwise applying it to the branches and trunks of flowers and trees can easily cause burns.

Chemical control: Because various pests and diseases are mostly in a dormant state in winter, chemical control can be adopted for those pests and diseases that are difficult to control during their occurrence season. For example, spraying 50-100 times diluted mineral oil emulsion can control scale insects, and spraying 1% Bordeaux mixture 2-3 times in late winter can achieve good control of many diseases such as pear rust and Chinese rose black spot.