How to prevent and control jujube witches' broom disease when growing jujube trees?

Recently, many readers have consulted us: their jujube trees are harmed by jujube witches' broom disease every year. What is going on? How should it be prevented and controlled? To address these questions, the reporter interviewed Feng Yibin, a researcher at the Zhengzhou Fruit Research Institute of the Chinese Academy of Agricultural Sciences.

Expert Feng said that jujube witches' broom disease, also known as witches' broom disease and male jujube disease, is a devastating disease of jujube trees and is mainly spread by disease-transmitting insects. The main factors affecting the length of the incubation period of jujube witches' broom disease are as follows: First, the grafting time. Inoculation before the end of June can cause disease in the same year, while inoculation after that shows symptoms only after flowering the following year. Second, the inoculation site. Inoculation on the roots causes disease in the same year, while inoculation on branches causes disease later, only in the following year. Third, the inoculation amount. When there are many bark graft pieces, disease develops faster. Jujube tree disease generally starts first on some branches, jujube spurs and root suckers, and some trees become diseased throughout the whole plant at the same time, with symptoms spreading from local parts to the whole plant. The occurrence of jujube witches' broom disease is related to the jujube variety; different jujube varieties also have different disease resistance. Jujube orchards with dry and poor soil, extensive management and weak tree vigor have more severe disease, and vice versa. However, it rarely occurs in saline-alkali land. The occurrence and spread of jujube witches' broom disease are also related to the altitude, slope aspect and propagation method of the jujube orchard. Prevention and control of jujube witches' broom disease should start from the following 4 aspects:

1. Select and breed disease-resistant varieties. Pay attention to discovering and using disease-resistant varieties; selecting and breeding disease-resistant varieties is the fundamental measure for preventing and controlling jujube witches' broom disease. 2. Eradicate diseased plants. Diseased jujube plants are the source of infection, so they must be eradicated as early as possible, and the roots must be dug out completely to avoid infecting other plants. 3. Control disease-transmitting insects. Spray systemic organophosphorus pesticides 3 to 4 times each year to control the number of disease-transmitting insects and thus control the spread of the disease. 4. Select and breed disease-free nursery stock and strengthen quarantine. Persist in collecting scions and budding eyes and propagating nursery stock in disease-free orchards to cultivate disease-free nursery stock. Once nursery stock shows disease symptoms, it should be pulled out immediately. In addition, quarantine should be strengthened to prevent transferring nursery stock and collecting scions from diseased areas.