My Defense Tomato Yellow Leaf Curve Viruses Cannot Be Delayed

Tomato yellow leaf curl virus (referred to as TY virus) was introduced to southern China in 2002 and spread to many provinces and cities across the country in 2008. The Beijing Fruits and Vegetables Innovation Team and the plant protection system of the city conducted sampling and appraisal on September 25-30, 2009. The results showed that the disease is now prevalent in our city, and it has occurred spot by piece, and some plots have become serious.

First, the characteristics of the disease and the cause of the disease

The disease is caused by a single-component twin virus infection, which mainly harms dozens of plants such as tomato, green pepper, tobacco, kidney bean, endive and various flowers. Mainly by the spread of poisonous B-type whitefly pollinators and artificial seedlings spread long-distance. The recent rapid spread of the Beijing suburbs has two main reasons:

Off-site seedlings spread disease. Due to the rapid advancement of facilities construction in recent years, many new vegetable bases in the suburbs have started production as soon as possible, and a large number of tomato seedlings that have not been tested by the plant protection and quarantine departments have been purchased from severely affected areas. Therefore, tomato yellowing leaf curl virus, which is the base for the induction of seedlings in other places, is widespread. Occurs and brings significant losses to production.

Grassroots technicians and vegetable farmers lack understanding of the disease. Tomato yellow leaf curl virus disease is a new non-quarantine disease. Grassroots technicians and vegetable farmers still do not understand the symptoms, characteristics, transmission routes and effective control methods of the disease. Prevention and control are blind.

Second, comprehensive prevention and control technology measures

1, select resistant varieties. Field trials in Shandong, Hebei, and other vegetable-producing areas indicated that tomato yellowing occurred in varieties such as tok-29, tok-30, tok-31, Provence 605, Feitian, Guanghui, Acura, loyalty, Zheza 301, and Suhong 9. Leaf curl virus has better resistance.

2, breeding insect-free disease-free seedlings. After the seedlings become infected, they not only cause the diseased plants to be rejected, but also become a source of rapid transmission among plants. Therefore, it is necessary to cultivate tomato seedlings that are free from the disease of the whitefly. When raising seedlings, attention should be paid to the following points: The nursery bed should be separated from the production field. The seedbed soil should be selected from soils that have not been sowed in the Solanaceae and cucurbit crops in recent years, and the seedling substrate and seedbed soil are sterilized to reduce the insect source. 50 to 60 mesh insect nets were used to isolate the seedlings to prevent virus infection at the seedling stage; the yellow seedlings inside the seedbed were hung under a height of 5 cm to trap the whitefly, so as to reduce the transmission medium, and the seedlings were killed 7 days before transplanting. Insect handling.

3, using grafting seedlings. Through a grafting experiment in Dagudian Village, Daxing District, the results showed that the incidence of grafting using "Jian An No. 1" was only 2%, while the incidence of control was 82%. Therefore, the "An Guo No. 1" and "Starlight" were adopted. Grafting such as rootstocks can significantly improve plant disease resistance.

4. Strengthen field control measures.

(1) Before the transplanting of seedlings, insecticide treatment should be performed on the whole shed. All the ventilation parts of the sheds are covered with 50-60 mesh insect-proof nets. The buffer doorway is set at the entrance, and the internal and external doors are staggered and prevented from opening at the same time to prevent poisonous tobacco powder. Enter the shed room.

(2) The diseased or suspected diseased plants were found to be removed in time and buried deeper than 40 cm. Remove weeds and debris from the field in time to reduce insect and poison sources. At the early stage of the disease, the symptoms may be confused with the deficiency of the disease and common mosaic virus disease, causing more serious losses. Please contact the local plant protection department in time.

(3) To promote the robust growth of tomato plants, increase the application of phosphorus and potassium fertilizers, keep the field moist, fertilizer and water management to a small number of times to improve plant disease resistance. Appropriate adjustment of planting time, due to whitefly migration from the greenhouse in the early spring of April to May to fly open damage, from September to October fall from the open back to the winter greenhouse damage, so adjust the seedling transplant time to avoid seedling exposure, Reduce disease occurrence.

(4) Because the whitefly breeding ability is strong and spreads rapidly, with sudden, explosive and devastating damage, it is recommended that the plant protection department concentrates on growing tomato and related solanaceae, cucurbitaceae, and leguminous crop areas. Under the rule of general defense, the reduction of the spread of tobacco whitefly between diseased and non-pathogenic fields can be achieved, thereby improving the control effect. Planting tomato in winter or spring, the temperature is lower, the occurrence of Bemisia tabaci is less, activity is not strong, it is the best season to control the spread of the disease and completely control Bemisia tabaci.

(5) In case of rapid increase of insect population during production, it is necessary to adopt emergency control of pesticides in a timely manner, and 25% thiamethoxam (Aketai) water dispersible granules may be sprayed at 5000 to 6000 times, or 25% buprofezin Ling) WP 1500 times mixed with 2.5% bifenthrin (Uranus) EC 3000 times spray. Be sure to spray evenly on the front and back of the blade when spraying, with particular emphasis on spraying the back of the blade. Due to the strong reproductive ability of Bemisia tabaci, it is easy to produce drug resistance, and it requires several agents to be mixed and used interchangeably. When the temperature is high or the temperature in the protected area is high, Bemisia tabaci active activity can be sprayed once in 5 to 7 days, and once in 10 to 15 days when the temperature is low.

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