In recent years, due to the change of farming methods and the abnormal climate, many soilborne diseases and underground pests such as stem rot, dry blight, total erosion and smut have increased year by year in China, and air borne diseases such as wheat stripe rust and powdery mildew have also appeared early and repeated, posing a great threat to the safety of wheat production. To do a good job in the prevention and control of diseases and insects in autumn and winter of wheat, and comprehensively promote the sowing of chemicals and seeds in autumn of wheat, not only can effectively prevent soil-borne, seed-borne diseases and underground pests, but also effectively control the damage of stripe rust, powdery mildew, aphids and other diseases and insects in autumn, significantly reduce the occurrence base of the next year, and reduce the control pressure in the middle and late stages of wheat growth, which is an important measure to achieve "insect-capture" and ensure the harvest.
1 Prevention and control strategies
Adhere to the plant protection policy of "prevention first and comprehensive prevention and control", implement the prevention and control strategy of "zoning management and classification guidance", fully implement the measures of fine preparation before sowing, planting resistant varieties, sowing in a reasonable and suitable period, and achieving standard control at autumn seedling time, so as to prevent and control the damage of wheat seed and soil-borne diseases, underground pests and diseases and insects in autumn and winter seedling. Lay a solid foundation for wheat pest control throughout the year.
2 Prevention and control objectives
In 2023, the overall coverage rate of winter wheat in autumn sowing was stable at more than 90%, an increase of 1-2 percentage points compared with the previous year; Among them, Huang-Huai-hai wheat and corn double cropping areas, as well as southwest, northwest, Hanshui River valley wheat stripe rust winter breeding areas, strive to achieve full coverage of pharmaceutical seed dressing, prevent "white seed"; In the middle and lower reaches of Yangtze River, Jianghuai wheat and rice double cropping areas, the rate of pesticide seed dressing remained above 85%.
3 Prevention and control targets
According to the occurrence characteristics of diseases and pests in the autumn and winter of each wheat growing area, the key control objects were determined and the prevention and control were carried out according to local conditions. Huanghuai sea wheat area focuses on the prevention and control of stem base rot, sheath blight, root rot, powdery mildew, yellow Mosaic virus, cyst nematode, wheat aphid, wheat spider, underground pests and other diseases. The wheat areas in the middle and lower reaches of the Yangtze River focus on the prevention and control of dry wilt, smut, wheat aphid, wheat spider, gray planthopper and other diseases and insects, and pay attention to stem rot. The wheat region of North China focuses on the prevention and control of root rot, stem rot, total erosion, wheat aphid, wheat spider and other diseases and insects. The northwest wheat region focuses on the prevention and control of stripe rust, powdery mildew, yellow dwarf, snow mold leaf blight (Xinjiang region), wheat aphid, wheat spider and other diseases and insects. The southwest wheat region focuses on the prevention and control of stripe rust, wheat aphids and wheat spiders.
4. Key prevention and control technical measures
(1) Planting resistant (tolerant) varieties
Optimize the distribution of varieties with excellent resistance according to local conditions. In the endemic areas of stripe rust in Huanghuai and middle and lower reaches of Yangtze River, plant resistant or slow rust varieties in adult stage. In northwest, Southwest and other areas where stripe rust was more prevalent in summer and winter, disease-resistant varieties were planted during the whole growth period, and the planting proportion of medium-high resistance varieties was increased to control the initial source of stripe rust. In the middle and lower reaches of Yangtze River, Huanghuai, North China and other areas where wheat scab, powdery mildew and stem rot occur, varieties with good resistance to SCab, powdery mildew and stem rot are selected. In the common and new areas of wheat yellow Mosaic virus disease, select the varieties with strong resistance to soil-borne virus disease.
(2) Deep stubble removal, fine land preparation, suitable for late sowing
Strengthen the field management before sowing, and dig the soil (25 ~ 30 cm) once every 2 ~ 3 years; Improve the fineness of the previous crop straw crushing, and apply organic fertilizer and straw maturing agent to accelerate straw decomposition, reduce the amount of pathogenic bacteria and reduce the incidence of disease and insect infestation. After sowing, field suppression was carried out scientifically to prevent the root suspension of seedlings and aggravate the harm of stem base rot, root rot, sheath blight, cyst nematode disease and freezing damage. In the source area of stripe rust, the spontaneous wheat seedlings, weeds and berberis around the wheat field should be removed in time to reduce the overwintering bacteria source of stripe rust. According to the occurrence characteristics of wheat stem base rot, dry wilt, aphids and other diseases and insects and the weather trend during autumn sowing, the sowing period of wheat should be appropriately delayed during sowing period, and the seed amount should be increased according to the late sowing days, so as to ensure the basic number of seedlings and reduce the occurrence degree of bacteria and pests before winter.
(3) Seed dressing or seed coating
Carry out seed dressing or coating according to local conditions and classification. In the areas where species and soil-borne diseases such as stem base rot, sheath blight, smut and root rot occur, select seed treatment agents containing pentazolol, phenoxymeclozole, flubenzocyclozil, pyrimidin, jinggangmycin and Bacillus subtilis for seed dressing or coating. Stem base rot prevention and control drugs can refer to the "Wheat stem base rot prevention and control technical Guidance" (Nongbannong (2023) 31). In summer and winter breeding areas of stripe rust and its surrounding wheat areas, triazole and Fumeisong were used to mix seeds or coat them, and at the same time treat mildew and smut at seedling stage. In the areas where total erosion occurs, silthiamide, phenoxymeclozole or Jingoka-cumon were used for seed dressing or coating. In the areas where underground pests and aphids occur at seedling stage, imidacloprid, thiamethoxam, thiamethoxam, chlorpyrifos, phoxius and other agents were selected for seed dressing or coating. In areas where multiple diseases and pests are mixed, seed dressing or coating is performed using antifungicides and insecticides or their combinations. Seed coating formulation was preferred during seed dressing or coating, and plant immune inducers containing brassinolactone, amino-oligosaccharide, immunoactivator protein and chlorin iron were added to improve wheat emergence rate and disease resistance and stress resistance.
(4) Strengthen the prevention and control of diseases and insects in autumn seedlings
In the early stage of wheat stripe rust disease, the control measures of "find one point, control one piece" were implemented, and triazole fungicide or pyrimidine nucleoside antibacterial spray was used for control, and triazole agents could also treat powdery mildew. On the basis of seed dressing prevention, chemical agents such as pyrhidone, acetamidine, antiaphidarb or biological pesticides such as matrine and Metarhizium anisoplast can be used to prevent and control the recurrence area of seedling aphid, and the transmission route of yellow dwarf disease can also be cut off. Abamectin, bifenthrin and other agents were used to control the wheat spider occurrence area. When the rate of leaf wilt and stem rot reached 10% or 5% respectively, the corresponding drugs were selected to control the field with early and repeated leaf wilt and stem rot.
5. Preventive and control measures
(1) Strengthen disease and insect monitoring
In autumn and winter, it is necessary to strengthen the monitoring of diseases and insects such as streak rust, stem rot, sheath blight, aphids, wheat spiders, sporycnematodes and underground pests, and regularly carry out systematic investigation and surface survey according to the requirements of the measurement and reporting standards, accurately grasp the occurrence of diseases and insects, timely release trend forecasts, and timely organize prevention and control actions for diseases and insects that meet the control targets. In the areas where stripe rust occurs, the first reward system should be implemented to achieve drug detection, standard prevention and control, early detection and early control, and lower the occurrence base of the next year.
(2) Promote publicity and guidance
Chemical treatment of autumn sowing seeds and disease and insect control of autumn seedlings are the first key to prevent and control wheat diseases and insects and ensure the steady increase of wheat yield per unit area. All localities should firmly shoulder the political responsibility for food security, strengthen organizational leadership, make arrangements as soon as possible, and ensure the orderly implementation of various measures. Make full use of various media platforms, banners, white paper and other means to publicize good technology, good experience and good practices for autumn and winter disease and insect control of wheat, create an all-round atmosphere for autumn and winter disease and insect control, improve the enthusiasm of farmers in autumn sowing and sowing seeds and autumn and winter disease and insect control, and provide support for improving the coverage rate of disease and insect control of medicine and autumn seedlings.
(3) Carry out service guidance
Wheat autumn sowing and sowing time is tight, the task is heavy, plant protection agencies at all levels should organize technical backbone in the key period of autumn sowing, carry out technical guidance and training activities, by holding on-site observation, holding seed mixing training, building prevention and control demonstration areas, etc. To guide new business entities such as family farms, large grain growers, seed industry enterprises, plant protection professional service companies and farmers to scientifically carry out pharmaceutical seed dressing and disease and insect control of autumn seedlings. It is necessary to further promote the construction of green technology demonstration bases for the prevention and control of wheat diseases and pests, strengthen the demonstration role of pharmaceutical seed dressing, physical and chemical induction and control, and green chemicals, radiate farmers to actively and scientifically carry out pharmaceutical seed dressing, and improve the level of wheat green prevention and control.
(4) Organize unified defense and rule
All localities should fully understand the significance of doing a good job in autumn sowing of wheat seeds and autumn seedling disease and insect control, effectively implement the territorial prevention and control responsibility, and actively organize various types of plant protection social service organizations, pesticide dealers, etc., to carry out unified autumn sowing and seed dressing and autumn and winter pest spraying services for farmers. In the areas where conditions are available, the whole system will promote the pesticide seed mixing work in towns and villages to achieve the reduction of pesticide quantity and increase efficiency. It is necessary to strengthen the scheduling of autumn sowing and sowing prevention and control materials such as road medicines and seed mixing equipment to ensure adequate supply and reliable quality.
Fluzocyclobacterin and other agents are recommended for the control of wheat autumn and winter pests
2023 10/11