2 pathogens, transmission routes and conditions
According to research, the wheat rosette virus is called the North Valley Mosaic Virus and belongs to the rhabdovirus group. The virions are rod-shaped, and the viral plasmids are mainly distributed in the cytoplasm, often in single or multiple layers, layered or clustered in the endoplasmic reticulum. In the salivary glands of the virus-mediated mediator, S. striata, the viral plasmid has only a nucleocapsid and no outer membrane. Virus sap in vitro 2 to 3 days, dilution point 10 to 100 times. Cong dwaranas incubation period varies with temperature, generally 6 to 20 days. Wheat bush dwarf virus is transmitted by sap, seeds and soil, and is mainly transmitted by SBPH. After the fly scorpion sucks. It takes a period of circulation to pass through the virus. The average daily temperature is 26.7°C, with an average of 10 to 15 days, and an average of 15.5 days at 20°C. 1 to 2 instar nymphs are easy to get the virus, and the ability to pass the virus is the strongest. The shortest period of time is 12 hours, and the shortest time is 20 minutes. The rate of drug acquisition and transmission rate increased with the increase of smoking time. Once acquired, it can be poisoned for a lifetime but not transmitted by the egg. The virus comes with poisonous nymphs and winters in its body. The winter wheat planthoppers in the winter wheat area migrated from the virus-bearing overwintering hosts to wheat fields in autumn and caused damage to the early autumn seedlings. Overwintering with poisonous nymphs in the weeds in the rhizosphere or earth seams overwintering is the source of poisoning in the following year. After the wheat matures, Smilax glabra migrates to rice, corn, weeds and other grasses to injure over summer. Wheat, barley, etc. are the main wintering hosts of the virus. Rice sheaths and wheat fields are more favorable for near-infestation and reproduction of SBPH, and the incidence of disease is heavy. Early sowing of winter wheat sows infestation of defoliation of Sphaerotheca falciparum is an early stage of disease and heavy disease incidence; incidence of heavy wheat fields near grassy slopes and weeds is heavy; summer, autumn and winter are warm, winter warm and winter cold. weight.
3 prevention measures
1) Remove field and field side weeds and winter water. Destroy the living environment of Laodelphax striatellus and reduce the overwintering base of Laodelphax.
2) The proper sowing of wheat. The most suitable sowing time for wheat in this county is between October 5-15, and rice and wheat will be sown before October 1. The chances of wheat being damaged by rice planthoppers will inevitably increase. Therefore, rice planting wheat should not be sown prematurely, and the symbiotic period of wheat and rice should be about 7 to 10 days.
3) Chemical control. The use of 50% phoxim EC as seed with 0.2% seed dressing can reduce the damage caused by SBPH to wheat seedling stage. Before the emergence of wheat to the three-leaf stage and wheat returning green stage, with 25% per acre Buxiuring WP 50 ~ 60g, or 10% imidacloprid WP 30 ~ 40g, or 50% phoxim EC 60 ~ 80m1, Add water 50 to 60kg spray. Pay attention to spraying pesticides on fields, roadsides, roadsides, and ditch sides to reduce the insect source and improve the effect of chemical control.
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