Large-leaved boxwood, also known as holly, guard spear and other nicknames, is an excellent landscaping plant, can be used as a hedge. With the large-scale use of landscaping, the harm of its diseases and insect pests destroys its appearance and even its death, which seriously affects the ornamental value of boxwood.
Common diseases
1. Powdery mildew
Powdery mildew can occur during the growth phase of boxwood, mainly harming young leaves and new shoots. When the plant is sick, it first produces small yellow spots on the surface of young leaves, and gradually expands in the later stage, and the spots gradually expand to form round or oval spots, with white powder on the surface. In severe cases, the leaves curl, the branches twist and deform, and even die.
Control method: Before the onset of the plant or the initial stage of the disease, it is recommended to use the "pink rust" 500 times liquid + "chlorophyll" 200 times liquid for foliar spraying, generally continuously used 2-3 times, with an interval of 7-10 days.
2. Anthrax
When anthrax is onset at the beginning of the disease, the pathogen invades from the leaf flesh of the leaf, so that the diseased part appears brown irregular spots, begin to become wet rot, the boundary of disease is not too obvious, with the development of the pathogen, the spot on the leaf is yellow, giving birth to nearly concentric charred small black spots, the disease can cause the leaf to fall off early. Anthrax has the characteristics of latent infection and is not easy to detect, and once it is epidemiced among susceptible plants, it is relatively difficult to control and cure the disease.
Control method: "ecological arrow" 500 times liquid or "spray sterile" 600 times liquid + "chlorophyll" 200 times liquid sprayed on the foliage, continuous use 2-3 times, interval 7-10 days.
3. Blight
In the early stages of the diseased boxwood, the upper leaves of individual branches are dried and dehydrated, and then the whole branch and the whole plant are green and dehydrated. In the later stages of disease , the leaves are yellowish-white. Not only does it affect the landscape effect, but when severe, it may cause direct plant death.
Prevention and control method: "ecological arrow" 500 times liquid + "root chun" 300 times liquid root irrigation treatment 3 times, the interval is about 10 days. Dead plants are recommended to be uprooted and soil sterilized with "sterilization".
Common pests
1. Red Spider
In the early stages of red spiders, they start from the back of the lower and middle leaves, and are infested by adult mites and mites sucking sap near the leaf veins, especially in the lower leaves, and then gradually spread. After the boxwood is damaged, the leaves are densely white needle-sized dots, and the leaves are gray and lose their luster. Red spiders are extremely small and difficult to detect, and once they are found to be harmful, they are often more seriously damaged by the plant.
Prevention and control method: "Shenrun Mance" 1000 times liquid + "chlorophyll" 200 times liquid spray foliar and leaf back, continuous use 2-3 times, intervals of about 5-7 days.
Second, the insect shell
The damage of the insects usually sucks the sap of the branches and leaves, and the excretion of honeydew often induces coal pollution disease, weakening the branches of the tree and dying.
Control method: "Shenrun Jiezhi" 300 times liquid spray pest damage site, use 2-3 times, interval 5-7 days.
3. Boxwood silk borer
Boxwood silk borer is one of the leaf-eating pests found in hedge plants such as large-leaved boxwood and small-leaved boxwood. It mainly harms the top and leaves of the plant, causing the branches and leaves to be bare, reducing the landscaping and ornamental value.
Control methods: It is recommended to use "Shenrun Lindan No. 1" with water 150kg-250kg during the nymph period, focusing on spraying pest damage sites; or use "Shenrun Lake" with water 150kg-200kg for uniform spraying.
Fourth, giddings
The large-leaved boxwood gradually developed from the initial sporadic death to the death of the pieces. A break from the root neck led to plant death, and a borer tunnel was found, which is a hazard of narrow giddings. The insect feeds on the stems of large-leaved boxwood with larvae, causing the plant to grow weak until it dies.
5. Tianniu
Tianniu larvae moth into the main trunk of the large-leaf boxwood from top to bottom, directly to the roots, the main moth to the ground to the branch below about 15-20 cm, the affected plant leaves faded green and white, the branches dried up or even the whole plant died. Similar to giddingia hazard symptoms.
Control method: "Through the set" spray tree body with 15-20 kg of water, use 2-3 times, intervals of 7-10 days;
The "tree insecticide" liquid is transmitted up and down through the flow of the tree protoplasm, and the liquid is spread throughout the tree, and the borer insects achieve gastric toxicity by biting the xylem. Note: Trees with a chest diameter of less than 5 cm cannot be used.