Fungicides such as fludioxonil, thiamethoxam, and difenoconazole have been recommended for seed treatment of autumn-sown wheat.

Recently, in order to effectively prevent and control major diseases and pests such as wheat stripe rust, stem base rot, aphids, and underground pests, the National Agricultural Technology Extension Center has formulated the “Technical Guidelines for Seed Treatment with Chemicals and Autumn–Winter Disease and Pest Management for Wheat in 2024.”

Technical Guidance on Seed Treatment with Chemicals and Pest and Disease Management during the Autumn-Winter Period for Wheat Sown in 2024

Chemical seed treatment for autumn-sown wheat is a key technical measure for controlling soil-borne and seed-borne diseases such as stripe rust, stem base rot, sheath blight, take-all, and smut, as well as aphids and underground pests. It effectively reduces the initial pathogen and pest populations, alleviates the pressure of disease and pest management in the mid- to late growth stages, and serves as an important strategy for safeguarding grain yields by “protecting crops from pests.” Moreover, it plays a crucial role in securing proactive control over wheat diseases and pests throughout the year.

I. Prevention and Control Strategies and Objectives

Adhering to the plant protection policy of “prevention first, integrated control,” and emphasizing “early intervention and small‑scale treatment, moving control points upstream,” we implement a prevention‑and‑control strategy of “zonal management and category‑specific guidance.” We also put into practice five key technical measures—deep plowing to eliminate stubble and prepare the soil, selecting disease‑resistant varieties, treating seeds with chemical agents, sowing at an appropriate late date, and conducting targeted control when autumn seedlings reach critical thresholds—to prevent and manage wheat diseases transmitted through seeds or the soil, as well as aphids, underground pests, and pest‑disease damage during the autumn–winter seedling stage, thereby strengthening the foundation of wheat disease and pest management. In 2024, the national coverage rate of chemical seed treatment for winter wheat during autumn sowing is to remain stable at above 90%; in particular, in the winter‑breeding areas of wheat stripe rust in the Southwest, Northwest, and Han River Basin, as well as in regions where stem base rot, underground pests, and root diseases are prone to recurrent outbreaks, we aim to achieve full coverage of chemical seed treatment and eliminate the occurrence of “white seeds” being sown.

II. Key Areas and Target Populations for Prevention and Control

Based on the recent trends in the occurrence and damage patterns of major diseases and pests in winter wheat-growing regions, key targets for prevention and control during the autumn and winter seasons have been identified.

Northwest Wheat Region: Focus on the prevention and control of stripe rust, stem base rot, yellow dwarf disease, snow mold leaf blight (in Xinjiang), wheat aphids, wheat spider mites, and other diseases and pests.

Southwest Wheat Region: Focus on controlling stripe rust, wheat aphids, and wheat spider mites, among other pests and diseases.

North China wheat-growing region: Focus on controlling stem base rot, root rot, take-all, cyst nematode disease, wheat aphids, and wheat spider mites, among other pests and diseases.

Yellow-Huai-Hai Wheat Region: Focus on the prevention and control of stem base rot, sheath blight, root rot, powdery mildew, wheat yellow mosaic virus disease, cyst nematode disease, wheat aphids, wheat spider mites, and underground pests.

Middle and Lower Reaches of the Yangtze River Wheat Region: Focus on controlling net blotch, powdery mildew, smut, wheat aphids, and wheat spider mites, while closely monitoring the occurrence of stem base rot.

III. Key Prevention and Control Technical Measures

(1) Prioritize the selection of resistant (or tolerant) varieties. In the stripe rust–prone regions of the Huanghuai and middle‑and‑lower reaches of the Yangtze River, give priority to planting varieties with high adult‑plant resistance; in areas such as Northwest and Southwest China where the stripe rust pathogen overwinters and reproduces during winter, increase the proportion of medium‑ to highly resistant varieties to reduce the initial inoculum of stripe rust; in wheat-growing regions including the middle‑and‑lower Yangtze River, Huanghuai, and North China, prioritize varieties that exhibit strong resistance or tolerance to scab, stem base rot, and other diseases.

(2) Deep plowing to eliminate stubble and delayed sowing at an appropriate time. In areas where soil-borne diseases such as wheat stem base rot and sheath blight are prevalent, strengthen pre-sowing field management by employing deep plowing to remove stubble, thereby reducing the pathogen inoculum. Depending on weather conditions, the wheat sowing date may be appropriately postponed, and the seeding rate slightly increased to ensure adequate stand density, thus lowering the likelihood of pathogen infection before winter and mitigating the severity of pest and disease outbreaks. In regions serving as sources of stripe rust, promptly remove volunteer wheat seedlings, weeds, and barberry plants around wheat fields to reduce the overwintering inoculum of stripe rust.

(3) Autumn‑sowing seed‑treatment technology. Based on the incidence of diseases and pests in major wheat‑producing regions, identify priority targets for control; centering on these key pests and diseases, select seed treatments that also effectively manage other pathogens and insect pests. Use seed‑treatment products or seed coatings already registered for wheat, and strictly adhere to the recommended application rates indicated on the pesticide label when mixing or coating the seeds. During treatment, consider adding plant growth regulators or immune‑inducing agents—such as brassinolide, iron‑dihydrochlorophyllin, aminooligosaccharides, or immune‑activating proteins—to enhance seedling emergence and stress tolerance. For areas where stem base rot is a concern: follow the recommended emergency control list for wheat stem base rot, selecting compound formulations such as fludioxonil–thiamethoxam, difenoconazole–fludioxonil–thiamethoxam, tebuconazole–imidacloprid, pyraclostrobin–trifloxystrobin, fludioxonil–pyraclostrobin, difenoconazole–fludioxonil, cyproconazole–tebuconazole, as well as single‑ingredient products like difenoconazole, pyraclostrobin, tebuconazole, prothioconazole, and triflumizole. These can also provide concurrent control of seed‑borne and soil‑borne diseases such as wheat sharp eyespot, smut, and root rot; when combined with insecticides, they offer additional protection against underground pests. In regions where stripe rust overwinters and reproduces during winter, as well as adjacent wheat‑growing areas: employ triazole‑based products and captan for seed treatment or coating, which simultaneously control powdery mildew and smut during the seedling stage. In areas where take‑all disease occurs: use silicon‑thiophanate‑methyl, difenoconazole, kasugamycin, or Jinggang–Bacillus subtilis preparations for seed treatment or coating. In areas prone to underground pests and aphids during the seedling stage: apply imidacloprid, thiamethoxam, clothianidin, chlorpyrifos, or phosmet for seed treatment or coating.

(4) Pest and disease management techniques for autumn seedlings. Seedling-stage stripe rust: At the early stage of infection, implement a “detect one, treat the whole field” approach, applying triazole fungicides (such as epoxiconazole, hexaconazole, propiconazole, and triadimefon) or biopesticides like pyrimidine nucleoside antibiotics via foliar spray; concurrently control powdery mildew. Seedling-stage stem base rot and sheath blight: When the incidence reaches 5%–10%, apply single‑component or mixed formulations containing cyproconazole, prothioconazole, propiconazole, pyraclostrobin, tebuconazole, cyazofamid, difenoconazole, benomyl, chlorothalonil, or thifluzamide by foliar spray. Seedling‑stage aphids: When the population reaches 500 aphids per 100 plants, use chemical insecticides such as pymetrozine, acetamiprid, pirimicarb, or lambda‑cyhalothrin, or biopesticides like matrine or Metarhizium anisopliae, applied as a foliar spray. Seedling‑stage wheat spider mites: When the density reaches 200 mites per 33 cm² in the field, apply abamectin, bifenthrin, or similar agents via foliar spray.

IV. Safeguard Measures and Prevention and Control Requirements

(1) Strengthen the implementation of responsibilities. Effectively implement the prevention and control mechanism of “government leadership and local accountability,” focusing on prevention and key periods, reinforcing organizational leadership, refining preventive and control measures, and ensuring that prevention and control efforts are carried out in a robust and orderly manner.

(2) Strengthen monitoring and early warning. Plant protection agencies at all levels should intensify pest and disease surveillance, accurately track their dynamics, and promptly launch control measures when thresholds are reached. In areas where stripe rust occurs, implement a first‑detection reward system to ensure timely detection with treated crops and effective control upon meeting threshold levels, enabling early identification and prompt containment.

(3) Strengthen guidance and services. With tight timelines and heavy workloads for seed treatment with fungicides during autumn wheat sowing, plant protection agencies at all levels should dispatch technical experts to the field during this critical period to conduct outreach and training, guiding farmers in implementing scientific pest and disease management. Particular emphasis should be placed on ensuring proper selection and application of pesticides to guarantee that preventive and control measures are effectively implemented.

(4) Strengthen integrated pest and disease management. Local authorities should enhance the coordination and allocation of seed‑treatment and control materials for autumn sowing, and fully leverage the role of specialized and socialized service organizations. In areas where conditions permit, implement, at the township or village level, comprehensive, system‑wide adoption of chemical seed treatment and synchronized foliar spraying during the seedling stage, thereby effectively elevating the organizational efficiency and scientific rigor of pest and disease control.

Source: National Agricultural Technology Center