Maize rough dwarf disease is a maize virus disease caused by corn roughage virus, and the field is mainly transmitted by SBPH. In addition to damaging corn, the virus can also infect wheat, barley, sorghum and so on. I. Symptoms: Corn is infected after emergence, plant leaves appear distorted growth, diseased seedlings are dark green, leaves are short and thick, hard and brittle, densely clustered, there are different lengths of wax and white strips on the veins on the back of leaves, touch with hands Obvious sense of roughness, plant growth retardation, emergence of dead seedlings, weak seedlings, usually need to destroy the field replanting; corn 3 to 5 leaves when infected, the upper section of the plant is swollen and dwarf, internode shortening, leaves clustered green, most Difficult to heading and fruiting, resulting in a serious reduction in yield; 5 to 7 leaves after the disease, dwarf diseased plants, dark green leaves, although the heading and fruiting, but the ear is small, thin grains, economic output is relatively low. Second, the conditions of the disease 1. Wide range of sources: natural host of toxic sources and mediators are widespread, most grasses and weeds are the host plants of maize rough dwarf disease, and in the third and fourth instar nymphs of winter migratory locusts In winter, the source of poison is more extensive. 2. Maize sowing date: The sowing period of corn is different and the degree of disease occurrence is different. The incidence of spring sowing and wheat interplanting is heavy, and the incidence of live killing after wheat harvest is lighter. 3. Variety: The degree of disease is different between different species. At present, there are fewer fine varieties with high resistance to maize rough dwarf diseases. 4. Field weeds: Roadside weeds in the field are hosts of the winter and summer overwhelming winter plover and viruses. They are also the basic conditions for the epidemic. However, in recent years, the weeds on the roadsides, channels, and other public areas have been seriously affected by corn rough dwarf diseases. Its mediators provided abundant intermediate hosts and vast wintering and summering sites, resulting in more severe onsets of land near the borders, trenches, and weeds. 5. Meteorological conditions: In the past few years, the temperature was too high in autumn, insects kill insects for a long time, resulting in an increase in the host's source of poisons over the winter; winter temperatures are high, the mortality rate of the winter-flying cockroach population of Laodelphax striatellus is relatively low; summer is even more rainy, It is conducive to the accumulation of poisonous insects in summer and field sources. 6. Tillage system: Maize cultivars have a long growing period, sowing too early, increasing the area of ​​wheat cultivars, and a long symbiotic period of wheat and corn. This cultivation method makes the maize seedling stage and the poisonous sedge fly nymphs become the nymph stage. Encountered, resulting in a large number of transmission of toxic sources, causing severe corn roughage. Second, prevention and control methods 1. Properly adjust the sowing date of maize: Appropriate late sowing of corn can effectively reduce the occurrence of the disease. Severe disease field should be destroyed after the wheat harvest, live from the middle of May to early June, generation of Laodelphax sinensis nymphs flourishing transmission period; mild disease field in the wheat harvest 5 to 7 days before the set of broadcast, try to shorten the wheat and corn Symbiotic period. 2. Use medium-early-maturing and disease-resistant varieties: After the investigation and investigation, the disease resistance among varieties was different. For example, Nongda 108, Ludan 981 and Denghai 11 are more resistant to disease and should be promoted. 3. Strengthen management: timely eradicate the weeds beside the trench along the roadside of Tianbian, timely cultivating and weeding, adding organic fertilizer, N, P, K with fertilizer, timely watering in case of drought, promoting seedlings to become early and robust, and enhance pest resistance Ability to remove diseased plants in a timely manner and bring them out of the field to be buried or burned. 4. Promote the use of coated seeds: The seed agent forms a protective barrier around the seed, which not only can prevent and control underground pests, but also prevent diseases. It can also be absorbed by corn as a result of seed excavation, and can also treat land insects such as slugs and aphids. The validity period is generally 35 days. about. 5. Elimination of insect sources: In the peak of adult diffusion and nymphal egg hatching peak period, before the migration of Laodelphax cornfield to corn, control with pesticides, choose 40% monocrotophos 1500 times, or 20% gray Lee 2000 times solution, or 20% methomyl 1500 times solution, or with 80% dichlorvos 500 milliliters mixed fine soil 25 kilograms, control focus is the land, Tanabe, ditches, roads on both sides of more weeds; When there is a migration hazard of Laodelphax striatellus after interplanting maize and corn, it is necessary to use the above-mentioned medicament or 10% imidacloprid 2000 times solution to treat fat in the field, and can receive better control effect. 6. Chemical control: For the diseased land, we can use 1.5% phytolithiasis 800 times solution, or 20% virus ninine solution 1000 times, and add 0.2% potassium dihydrogen phosphate solution and spray them after mixing, which can effectively control the disease.
Dimercaptosuccinic Acid,Hawthorn Leaf Powder,2 3-Dimercaptosuccinic Acid
Senyuan Biological Technology Co., Ltd. , http://www.hnvitamins.com