Black pine, also known as white bud pine, is an evergreen tree that can reach heights of up to 30 meters and has a grayish-black bark. It is native to Japan and the southern coast of Korea.
It is mainly transmitted by the Tianniu (mainly the pine brown Tianniu). After infection with pine wood nematodes, there are no obvious external features in the early stages. If you find that pine trees are retreating without warning, you should be vigilant.
Prevention and control methods
Use thiamethoxine 1000 to 2000 times liquid to control tianniu, and can also hang black light or frequency vibration insecticidal lamp to trap tianniu. Hanging needles on the tree body with 1.8% avermectin emulsion 1000 to 2000 times liquid can control pine wood nematodes.
Caused by fungi of the genus Flaky crusts, it is transmitted by air currents. Conditions such as poor soil, weak trees and too humid environment are conducive to the spread of the disease. After overwintering, the pathogen matures in March to April of the following year, and produces spores in April to May. It is generally infested with 2-year-old conifers, and can be infected with conifers of that year in the later stages. The most suitable conditions for spore transmission are about 25 °C per day and a relative humidity of more than 90%.
Control with methyl tolbutazine 1500 times liquid or 45% daisen ammonium 200 to 300 times liquid.
Seasonal pests, which are transmitted to each other by surrounding trees ( especially rosaceae plants ) . Environments with insufficient light and poor ventilation are more susceptible to infection. The frequency of aphid damage is high, and some areas can occur in addition to severe winters, so it is necessary to pay close attention to and prevent and control them in time. Control is carried out in March and overwintering pests are controlled in December.
Spray 3 times with imidacloprid 1000 times liquid, each time at intervals of 3 days and 7 days, and can also be controlled with 1500 times of dichlorvos.
Seasonal pests, which are transmitted through seedling transport and adult flying on their own. Control is carried out in late March to April and early July, and overwintering pests are controlled in December.
Control with 50% octylthion emulsion 1000 times or 2.5% cypermethrin emulsion 1500 to 2000 times liquid.