Platycladus orientalis, what's going on What disease and how to prevent it?

Common diseases and pests of Platycladus orientalis and their control methods;

1. The most common pests and diseases of Platycladus orientalis are: oriental arborvitae caterpillar, oriental arborvitae aphid and Monochamus alternatus. The following are the control methods of these three pests:

1, control of arborvitae hairy pests

(1), agricultural prevention and control should strengthen forest management, timely pruning and cutting, centralized burning of insect bark during the overwintering period, and artificial capture when larvae occur.

② Physical control According to the phototaxis of adults, a black light is set to trap and kill adults.

③ There are many natural enemies in the biological control of this insect. When the occurrence amount is small, chemical control should be avoided as far as possible, and natural enemies should be protected, such as releasing parasitic bees.

④ When the larval density of chemical control is high, it should be treated as early as possible. Use 25% diflubenzuron No.3 to control larvae in a low amount, with the dosage of 23-45g per mu and the spraying amount of 10.5kg, which should be sprayed in sunny and windy days.

2. Prevention and control of arborvitae aphid damage

(1), clever use of natural enemies

Such as ladybugs, harmonia axyridis, sunlight bees, aphid bees, crown gall bees, lacewings and syrphids. When the pests are not serious in spring, try not to use chemicals, but spray clean water to wash the pests to protect the reproduction and development of natural enemies in the future.

(2), chemical control

When the insect pest is serious, 25% Aketai water dispersible granule or 20% Kangfuduo concentrated solvent 5000 times can be sprayed.

3. Control of Monochamus alternatus pests

(1), strengthen tending management, prevent and eliminate pests and diseases.

(2), mobilize the masses, artificial arrest.

③ Chemical control.

④ Protecting and utilizing natural enemies.

Second, the most common diseases of Platycladus orientalis mainly include: Platycladus orientalis leaf blight, Platycladus orientalis leaf blight and Platycladus orientalis red spider, and their control methods are as follows:

1, Control of Leaf Blight of Platycladus orientalis

(1), clean the burned diseased leaves and pollution sources under the tree in autumn and winter. Eliminate winter germs and reduce the first invasion.

② From May to August, spray 1 time 1: 1: 100 bordeaux solution every two weeks for prevention, and pay special attention to strictly control the initial infection. If the initial infection center is found, it should be blocked to prevent transmission.

(3) The dense cypress forest should be thinned properly, so that the forest is ventilated and transparent, and the disease conditions can be reduced.

2. Control of Platycladus orientalis leaf blight

(1) Moderate pruning can improve the growth environment of Platycladus orientalis and reduce the source of infection.

(2) fattening and promoting growth.

③ Spraying 40% mirex, 40% carbendazim or 40% chlorothalonil 500 times solution for control during the peak period of ascospores release.

④ Selection of disease-resistant varieties.

In addition, the main control methods of Platycladus orientalis red spider are:

1. It can be washed with clean water or with 0. 1-0.3 degree stone sulfur mixture without affecting the growth and appreciation of trees.

2. Scatter the granules evenly at the bottom of the ditch and cover the soil with clear water.