Research and Prevention of Maize Rough Disease
Maize rough dwarf disease is a maize virus disease caused by corn roughage virus (MRDV). MRDV belongs to the plant reovirus group and is a double-stranded double-stranded RNA spheroid virus that is transmitted by Laodelphax striatellus in a persistent manner. Maize rough dwarf disease is an important disease in the maize production area in northern China. The perennial corn planting area in Qufu is 375,000 mu, and the occurrence of rough dwarf disease is relatively common. The rate of serious diseased field is as high as 30%, which is an important factor restricting the further increase of corn production in the city. 1 Symptoms of corn rough dwarf disease and damage to corn plants infected with MRDV are short, stiff and straight, with dark green leaves. The internodes are thick and short, with the top leaves clustered like a clivia. Leaf veins, leaf sheaths, and temporal lobes have waxy white sticks on the veins of the leaves, showing a noticeable roughness. The plants are severely dwarfed, the tassels are degenerated, and the ears are deformed. When they are severe, they cannot be strong. Since 1993, the occurrence of maize rough dwarf disease (MRDV) has apparently increased, causing great losses to the city's corn production. When the disease occurred in 1996, the average diseased field strain rate reached 40%, and the average yield was reduced by 10% to 30%. How to control the damage of corn virus disease, especially maize rough dwarf disease (MRDV), has become a very practical issue. Therefore, we have conducted a systematic survey of maize rough dwarf disease in recent years. The study found that: 85.16% of the maize plants in the diseased plant sample were almost always or never produced, the plant height was only 1/2 of that of the healthy plant, and there was no grain in the ear or ear; 98.44% of the plants had a loss rate of grain weight. above 50. 2 Comprehensive prevention and control methods for corn rough dwarfs In the prevention and control of corn rough dwarf diseases, we must adhere to an integrated prevention and control policy based on agricultural control and supplemented by chemical control. Its core is to control the source of poisons, reduce the source of insects, and avoid hazards. 2.1 Strengthen Monitoring and Forecasting Focusing on the regular occurrence of diseases, regular surveys will be conducted on the rate and severity of disease-diseases in wheat, field weeds, and maize, and the occurrence density and virus-infecting rate of Laodelphax striatellus will be investigated. Before and after the end of autumn and late spring and corn planting, based on the wintering base and the rate of disease, the diseased planting rate of wheat and weeds, combined with the corn planting model, timely and accurate prediction and forecast of the occurrence trend of maize rough dwarf disease was conducted. Prevention. 2.2 Selection of Disease-Resistant Varieties Despite the lack of strong disease-resistant seed varieties in the main cultivars currently used in maize production, the degree of susceptibility among the cultivars still differs. Therefore, according to local conditions, select relatively resistant varieties, at the same time pay attention to a reasonable layout, to avoid the large-scale planting of a single resistance source varieties. In Qufu City, the maize hybrids Ludan 50 and Lu Yuandan 14 have good resistance to rough dwarf diseases. 2.3 Adjustment of sowing date According to the law of occurrence of corn rough dwarf disease, in the disease recurrence area, the sowing date should be adjusted so that the corn will avoid the occurrence period of adult Spodoptera furnacalis in the most sensitive breeding period and reduce the incidence rate. There are three types of corn planting modes in the city: wheat husks, grab corn, and late sowing corn, of which wheat cultivar has the most serious disease, followed by grab corn and once again sowing corn. Spring sowing of corn should be planted before mid-April; summer sowing of corn should be concentrated from the end of May to the beginning of June. 2.4 Weed removal Roadside and field weeds are not only the provenance base of weeds in farmland in the coming year, but also the wintering and summer hosts of the corn silkworm, a drug-mediated mediator of corn rough dwarf disease. Clearing weeds to a certain extent can reduce the damage of corn rough dwarf disease. 2.5 Strengthen field management in conjunction with constant seedlings, remove diseased plants in the field, and concentrate deep or burn in order to reduce the source of invasive disease. Rational fertilization and watering, strengthening of field management, promotion of corn growth, shortening the period of disease, reducing the chance of transmission, and enhancing the resistance of corn to disease resistance. 2.6 Chemical control First, seed dressing. The use of systemic insecticides to coat and seed corn seeds can effectively prevent and control the emergence of Laodelphax and reduce the spread of rough and contracted diseases. The second is spraying pesticides. Before and after corn sowing and at the seedling stage, spraying insecticides on corn fields and nearby weeds to control SBPH has a certain effect on reducing the damage of rough dwarf disease, and it can achieve the effect of pest control and disease prevention. (Author: Zhu Dejun Wang Qiuqin NIU Fu Ying Ma Jianping Unit: Qufu City, Shandong Province Bureau of Agriculture)
Ultrasonic Surgical System，High-Frequency Electrosurgical System
Changzhou Ziying Metal Products Co., Ltd , https://www.ziyingmetal.com