Winter pest control of Pinus sylvestris var. mongolica
In winter, the overwintering sites for garden plant diseases and pests are relatively fixed and concentrated, which is a critical period. Winter pests mostly overwinter as eggs, larvae, cocoons, and adults (scale insects) in soil, dead branches, weeds, bark, cracks, bud axils, branches, and other areas; Most pathogens overwinter in diseased remains and soil as mycelium and spores. If cicadas lay their eggs on the branches of osmanthus, agarwood, and camphor trees to overwinter (there is white substance at the egg laying site), the branches above that site will wither and die; The small leaved fig psyllid overwinters as nymphs and eggs in the leaf axils. It is necessary to promptly remove these overwintering pests and clean the overwintering sites.
Clear away dead branches, fallen leaves, and weeds; Cutting off diseased and overlapping branches can directly eliminate a large number of overwintering pests and pathogens, improve plant ventilation and light transmission conditions, and enhance tree vigor for the following year; Artificially removing cocoons, egg masses, insect bracts, and scraping overwintering scale insects; Plowing soil to resist sunlight and reduce overwintering pests and diseases in the soil; At the same time, it is important to take measures to prevent the spread of pests and diseases.
Whitening of tree trunks should be carried out in December after leaf shedding and before soil freezing. This not only kills pests and diseases that overwinter on tree trunks, but also effectively reduces frost damage. Whitening materials include quicklime, sulfur (or stone sulfur mixture), water, and salt; The white coating height is 1.1 meters.
Pay attention to antifreeze in winter. Freezing damage is caused by the rapid drop in temperature, which leads to the formation of highly permeable non lipid gaps on the plant protoplast membrane, causing leakage of intracellular substances and resulting in cell death. Cutting off the tender branches that sprout in early winter can promote lignification and nutrient accumulation of the branches, and improve their cold resistance; Stop applying nitrogen fertilizer to trees and apply some phosphorus and potassium fertilizers appropriately; Spraying antifreeze agents to enhance the plant's frost resistance and reduce the mechanical damage to the membrane system caused by the formation of frozen crystals in the protoplasts at low temperatures; Root neck soil can prevent root neck and tree roots from frostbite, while also reducing soil moisture evaporation; For non cold resistant tree species, wind barriers can also be installed in the upwind direction of the trees.