What are the prevention and control methods of root rot of Chinese fir?

Root rot is a common disease in southern China, which does great harm to Cunninghamia lanceolata and can cause the death of a large area of seedlings. So what are the prevention and control methods of Chinese fir root rot?

Symptoms and conditions of root rot of Cunninghamia lanceolata

1. Main symptoms

At the initial stage of the disease, only a few lateral roots and whisker roots were infected, and gradually extended to the main root. after the main root was infected, the early plant symptoms were not obvious, and then the absorption function was gradually weakened with the aggravation of the degree of root rot. as a result, the aboveground parts can not get effective replenishment of water and nutrients, especially when the light is strong and the evaporation is large around noon. When the disease was mild, the upper leaves of the plant wilted, but recovered at night. When the disease is serious, the wilting condition can not recover at night. At this time, the root bark turned brown and separated from the pith, resulting in the death of the whole plant.

2. Morbidity condition

Root rot is a fungal disease, and the pathogens are Sclerotinia uniformis and Basidiomycetes. The pathogen spends the winter in the soil and on the residual body, generally entering the onset period in May, and the peak period is from July to August. The degree of the disease is closely related to the climatic conditions. The high temperature, high humidity and insufficient light in the greenhouse in the north can easily lead to the occurrence of this disease. The stickiness of matrix, lack of fertility and poor ventilation hinder the growth and development of root system, which is also easy to occur.

2. control methods of root rot of Cunninghamia lanceolata

1. Strengthen the cultivation and management of seedlings.

Improve the conditions of ventilation and light transmission, and try to avoid the continuous breeding of a single variety of seedlings.

2. Disinfection of plant materials

The seeds can be specially treated with 0.3% of the seed weight, or soaked in 2000 times of 80% EC for 5 hours; the base of the cuttings can also be dipped in the same concentration for 1 hour, and then sowed or cut.

3. Disinfection of seedbed matrix

With 50% carbendazim 1.5 g per square meter, or 75% pentachloronitrobenzene 3G sprinkled on the surface, and then turned into the soil, can play a disease prevention and treatment effect, but also can prevent and cure sudden disease, blight disease.

4. Chemical control

When the disease occurs, the diseased plants can be sprayed or irrigated with 1000 times of Gen Fu Ning, 1500 times of 80% EC and 1% of copper sulfate.

5. Strengthen daily management

The main results are as follows: (1) improve the tree potential, improve the ability of disease and insect resistance, and increase the application of organic fertilizer.

(2) turn the soil deeply to increase the air permeability of the soil.

(3) root filling treatment with specific drug for root rot disease.

Warm reminder: Cunninghamia lanceolata is generally fond of warm, moist, breezy climate and deep, loose and fertile soil with good drainage. According to the purpose of cultivation, afforestation plots are selected to adapt to trees and local conditions. generally, it is better to choose the sloping land with fertile soil at an altitude of 300-800m, and the soil type is mountain red soil or mountain yellow soil.