High incidence of virus disease in broccoli in summer and autumn how to control virus disease in broccoli

The main disease of broccoli is virus disease, which is widely distributed, widespread and serious, with a high incidence in summer and autumn, with a general diseased plant of 10% ~ 30 ‰, which has little impact on yield, as high as 60% ~ 80%, or even higher, seriously affecting the yield of broccoli.

Broccoli virus disease

[symptoms]

The virus disease occurred more seriously in the seedling stage. At the initial stage, there were near-round small chlorotic spots on the leaves, and then the color of the leaves became lighter, or green spots appeared alternately, then the leaves shrunk, twisted and deformed, and finally the whole plant died. In the adult stage of broccoli, in addition to uneven spots in the tender leaves, sometimes dark brown necrotic spots appear on the back of the old leaves, or accompanied by vein necrosis, the final dwarfing deformity, the petiole is crooked, the proportion of the inner and outer leaves is out of balance, and the bouquet becomes smaller if it is light. if it's heavy, it doesn't bear balls at all.

[pathogen]

The virus disease is mainly caused by turnip mosaic virus infection, and also caused by cucumber mosaic virus (CMrv), tobacco mosaic virus (CMV), radish mosaic virus (TMV) and other viruses alone or mixed with TuMV. Granulosomal linear turnip mosaic virus, size 70000nm × 1218nm, detoxification temperature 5500nm, 10min, dilution limit 1000 times, in vitro virus preservation time 4872h, transmitted through aphids or contact friction, mainly transmitted by aphids in the field.

[morbidity regularity]

Viral diseases are high in warm areas, and the virus accumulates on cabbage, kale, radish or spinach for the winter. Then the source of the toxin was transmitted to broccoli by peach aphid, cabbage aphid and cabbage aphid. With high temperature and drought and high ground temperature, the disease resistance of broccoli decreased significantly, while aphids multiplied rapidly and frequently, causing virus diseases to occur generally. If the management is extensive, the soil is dry, lack of water and fertilizer, the disease will be serious.

[prevention and control methods]

1. Select more disease-resistant varieties of broccoli according to local conditions, such as Lilu, Green Ridge, Jasda and so on.

2. Reasonable intercropping, intercropping and rotation, planting in summer and autumn, there should be a certain distance from other cruciferous vegetables, and the seriously sick broccoli plants should be pulled out in time.

3. Adopt the cultivation technique of covering sunshade net or non-woven cloth, increase the application of organic base fertilizer, pay attention to watering small water frequently in high temperature and dry season, control aphids and control the occurrence and spread of virus diseases.

4. At the initial stage of the onset of virus disease, spray broccoli with 20% virus A wettable powder, or 1000 times with 1.5% Zhishiling emulsion, or foliar spraying compound fertilizer to restrain the disease and enhance host disease resistance.