Jujube witches' broom disease is a common disease affecting jujube trees. Once infected with jujube witches' broom disease, all parts of the tree will be damaged, significantly impacting the yield and health of the jujube tree. Below are comprehensive measures for controlling jujube witches' broom disease.
1. Selection of Healthy Seedlings
When establishing an orchard, select healthy seedlings and strictly avoid transplanting from diseased areas. Propagate disease-free seedlings through grafting, budding, or root division from disease-free jujube orchards. During transplantation, choose robust seedlings with developed roots and lush leaves for planting.
2. Field Sanitation
The roots of jujube trees can harbor pathogens year-round. Overwintering pathogens in the roots are an important source of infection for jujube witches' broom disease in the following year. After harvest, promptly remove weeds and diseased leaves from the jujube orchard.
3. Fertilization and Irrigation Management
For young jujube trees, fertilize by digging a circular trench 40-50cm away from the outer edge of the tree canopy, 30cm deep. Apply basal fertilizer evenly and water after covering the trench with soil. Every two years, apply radial trench fertilization once. After each fertilization, water promptly. Additionally, water once before budding and once during flowering and fruit setting. During the fruiting period, apply organic fertilizer at a rate of 100kg per plant, urea at 1kg, and compound fertilizer at 1kg. Mix evenly under the tree and plow to a depth of 20-30cm, applying less near the trunk and more away from it. Apply quick-acting nitrogen fertilizer during the flowering period, and apply compound fertilizer containing nitrogen, phosphorus, and potassium after flowering and during fruit expansion.
4. Soil Improvement
Control jujube witches' broom disease by adjusting soil acidity and alkalinity. Improve the soil to reduce leafhopper populations, thus decreasing the occurrence of jujube witches' broom disease.
5. Leafhopper Control
Effective control of leafhoppers can slow down the spread of jujube witches' broom disease. Spray insecticides from late April to the end of June. In late April, spray with imidacloprid to control young leafhoppers. In late May, spray with pyrethroid insecticides to control the first-generation leafhopper nymphs. In late June, spray again with imidacloprid emulsion to control the first-generation adult leafhoppers. In late July, spray with lambda-cyhalothrin. After harvesting, spray with pyrethroid insecticides for control.
6. Timely Pruning
Pruning the trunk at the right time can effectively inhibit the occurrence of jujube witches' broom disease. Before budding, perform trunk pruning. Before leaf drop, remove broom branches and destroy them to prevent secondary infection. Timely removal of diseased shoots during the growth period can effectively suppress the occurrence and spread of jujube witches' broom disease.
7. Chemical Control
In early spring, drill 2-3 holes on the trunk at a height of 60cm from the ground and insert cotton soaked in thiophanate-methyl into the holes, covering them with plastic film. Apply twice a year. Alternatively, drill holes at the base of the trunk and inject 400mL of 10 million units of terramycin per hole. This method has a certain effect on plants with mild jujube witches' broom disease.
Above are the comprehensive measures for controlling jujube witches' broom disease. This disease is common in jujube trees and poses a significant threat to their health. It is essential for growers to implement effective management practices for prevention and control.
