2015 Technical Guidance on the Prevention and Control of Wheat Pests and Diseases in Autumn and Winter

◆Adhere to the principles of "highlighting key areas, regional governance, adapting to local conditions, and classified guidance," and implement the plant protection policy of "prevention first, integrated control."

◆Adopt a prevention and control strategy that integrates green control with unified prevention and control, apply comprehensive measures including agricultural, biological, physical, and chemical methods, focus on planting disease-resistant varieties, vigorously promote seed treatment with chemicals, reasonably adopt appropriately delayed sowing, and remove volunteer wheat seedlings in fields and weeds along field edges and roadsides.

In order to further strengthen autumn sowing seed treatment of wheat and the prevention and control of pests and diseases in autumn and winter, the National Agricultural Technology Extension Service Center and the Pest and Disease Prevention and Control Function Research Office of the National Wheat Industry System organized relevant experts and put forward technical guidance on the prevention and control of major wheat pests and diseases in autumn and winter in different production regions of China. We have excerpted the main contents for your reference. -- The Editor

Key targets of control

Huang-Huai-Hai wheat region: mainly sheath blight, root rot, take-all, smut, cyst nematode disease, yellow mosaic disease, underground pests, and weeds, while also controlling seedling-stage rust, powdery mildew, aphids, and small brown planthoppers and other pests and diseases.

Middle and lower Yangtze River wheat region: mainly sheath blight, take-all, loose smut, and stinking smut as the main targets, with underground pest damage in a small number of fields.

Southwest wheat region: mainly wheat stripe rust, while also taking into account fusarium head blight, powdery mildew, wheat aphids, wheat spiders, and underground pests and other pests and diseases.

Northwest wheat region: mainly wheat stripe rust, powdery mildew, stinking smut, and underground pests as the main targets of control.

Planting resistant (tolerant) pest- and disease-resistant varieties

In the southern Huang-Huai region where stripe rust frequently occurs, varieties with rust resistance or slow rusting such as Zhoumai 17, Yumai 34, Yumai 49, Yumai 69, Xinmai 19, Xinong 979, and Xiaoyan 6 should be planted in areas where the disease occurs early and severely year after year. In areas with severe cyst nematode disease, varieties with a certain degree of disease resistance such as Taikong 6, Zhongyu 6, and Xinmai 11 should be selected for planting. In areas where wheat yellow mosaic disease frequently occurs and in newly affected areas, relatively resistant varieties such as Xinmai 208, Yumai 70-36, Fanmai 5, Yumai 70, and Zhengmai 366 can be planted.

In the middle and lower Yangtze River wheat region and areas with severe fusarium head blight, varieties with a certain resistance or tolerance to fusarium head blight and other diseases should be selected to reduce the pressure of using chemical pesticides for controlling wheat fusarium head blight later.

In the southwest wheat region, mainly stripe rust-resistant varieties should be used. According to local conditions, disease-resistant varieties such as Mianzamai 168, Mianmai 37, Mianmai 39, Mianmai 41, Mianmai 43, Mianmai 45, Chuanmai 42, Chuannong 18, Xikemai 2, Emai 18, Yunmai 2, Qianmai 15, Zhoumai 17, and Wanmai 53 should be selected.

The northwest wheat region is the summering area of wheat stripe rust. In different altitude areas of this region, selecting and planting improved wheat varieties containing different disease-resistant genes plays a very important role in controlling the spread of wheat stripe rust and the amount of initial inoculum. In wheat areas around summering areas such as the mountainous areas of southern Gansu and Liupan Mountain, resistant (tolerant) varieties should be planted according to conditions. In other areas of the northwest wheat region, local varieties with good quality, disease resistance, and high yield should be selected as much as possible according to conditions.

Seed treatment with chemicals

According to pest and disease conditions, choose high-efficiency suspension seed coating agents such as tebuconazole, difenoconazole, fludioxonil, and difenoconazole·fludioxonil to coat wheat seeds to prevent diseases, and use an appropriate amount of imidacloprid suspension seed coating agent for coating to prevent pests, yellow dwarf disease, and dwarf disease. Mixing the two can control major pests and diseases at the seedling stage at the same time. In the summering area of stripe rust and surrounding wheat areas, use seed coating agents such as triadimefon and tebuconazole for seed treatment to simultaneously control seedling-stage stripe rust and powdery mildew and prevent later occurrence of stinking smut and other diseases. In areas where take-all occurs, focus on seed treatment or coating with difenoconazole suspension seed coating agent and silthiopham (Silthiopham) suspension concentrate; for underground pests, phoxim or chlorpyrifos can be used for seed treatment; for fields with particularly severe soil-borne diseases and underground pests, chemical soil treatment should be carried out. In areas where multiple diseases and pests occur together, according to the main local pest and disease species, compound seed coating agents or seed treatment agents containing fungicides and insecticides can be used for coating or seed treatment. The active ingredients of each single agent in the compound (mixed) agent should be roughly the same as when used alone. In areas where seedling-stage aphids, wheat spiders, and underground pests cause relatively severe damage, use phoxim or imidacloprid suspension seed coating agents for seed treatment.

Agricultural measures

In areas of the Huang-Huai wheat region where corn straw is returned to the field, fine land preparation should be done, burying corn straw in the soil as much as possible, clearing residual stalks from the field, and after emergence, combining winter irrigation with compacting wheat seedlings. In areas or fields with severe cyst nematode disease, focus on promoting post-sowing and autumn seedling stage compaction measures to control the disease. In the summering area of wheat stripe rust, manual removal and spraying of herbicides should be used to clear volunteer wheat seedlings. At sowing time, according to soil moisture, appropriately delayed sowing should be adopted to reduce infection by stripe rust at the seedling stage, reduce seedling-stage diseases, and lower the amount of inoculum on autumn seedlings.

Autumn seedling control

According to the occurrence of diseases such as stripe rust, powdery mildew, and sheath blight on autumn seedlings, when the disease occurrence is severe, carry out spot treatment to protect the surrounding area. In the southern Shaanxi region, which is the winter reproduction area of stripe rust fungus, strengthen monitoring and carry out chemical control in early diseased fields. Triazole fungicides can be selected for spray control. In areas where sheath blight occurs at the seedling stage, strengthen monitoring and carry out control as early as possible; in the Weibei dry plateau area, the eastern Gansu region, the southern Gansu region, and the winter wheat area of southern Ningxia, on the basis of seed treatment prevention, attention should be paid to controlling seedling-stage aphids and preventing the occurrence of wheat yellow dwarf disease. Early winged aphids can be trapped and killed with yellow boards, and for chemical control, high-efficiency low-toxicity insecticides such as imidacloprid and pymetrozine can be selected for spray control.