Technical guidance on prevention and control of wheat diseases and insect pests in autumn and winter

The prevention and control of diseases and insect pests in wheat sowing period is of great significance to depress the initial amount of diseases and insect pests, prevent the occurrence of diseases and insect pests at seedling stage, and ensure the effective control of wheat diseases and insect pests in the whole year. In order to implement the spirit of the 2015 Autumn and Winter seed Conference of the Ministry of Agriculture and further strengthen the seed dressing of wheat sowing in autumn and winter and the prevention and control of diseases and insect pests in autumn and winter, our center and the national wheat industry system pest prevention and control function research room organized relevant experts, combined with the occurrence of wheat diseases and pests in spring and summer in 2015, put forward technical guidance for the prevention and control of major wheat diseases and insect pests in autumn and winter in different producing areas of China.

(1) highlight the key areas and the objects of prevention and control. According to the planting situation of winter wheat in China this year and the occurrence regularity of diseases and insect pests over the years, the prevention and control of wheat diseases and insect pests in autumn and winter are mainly in Huang-Huai-Hai wheat region, middle and lower reaches of the Yangtze River, southwest wheat region and northwest wheat area. The main diseases in Huang-Huai-Hai wheat region are sheath blight, root rot, total erosion, smut, cyst nematode, yellow mosaic, underground pests and weeds, as well as seedling rust, powdery mildew, aphids and gray planthoppers. In the wheat area of the middle and lower reaches of the Yangtze River, sheath blight, total erosion disease, scattered smut and fishy smut were the main objects, and a few fields were damaged by underground pests. Wheat stripe rust is dominant in southwest wheat region, taking into account diseases and insect pests such as scab, powdery mildew, wheat aphid, wheat spiders and underground pests. Wheat stripe rust, powdery mildew, fishy smut and underground pests are the main control targets in northwest wheat region.

(2) planting varieties resistant to diseases and insect pests. The southern part of Huang-Huai is a frequent occurrence area of stripe rust. Rust-resistant and slow-rust varieties such as Zhoumai 17, Yumai 34, Yumai 49, Yumai 69, Xinmai 19, Xinnong 979 and Xiaoyan 6 should be planted in the areas with early and recurrent occurrence of stripe rust. In the areas where cyst nematode disease is serious, varieties with certain disease resistance should be planted, such as space 6, Zhongyu 6, Xinmai 11 and so on. Resistant varieties such as Xinmai 208, Yumai 70-36, Panmai 5, Yumai 70 and Zhengmai 366 can be planted in the frequent and new areas of wheat yellow mosaic disease. In the wheat areas of the middle and lower reaches of the Yangtze River and the areas with heavy occurrence of scab, varieties with certain resistance to scab and other diseases should be selected to reduce the pressure of using chemicals to control wheat scab in the later stage. The southwest wheat region is mainly resistant to stripe rust. According to local conditions, resistant varieties such as Mianza 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 were selected. The northwest wheat region is a summer area of wheat stripe rust. Planting improved wheat varieties with different resistance genes in different elevations in this area plays a very important role in controlling the spread of wheat stripe rust and the initial bacterial source. Disease-resistant (tolerant) varieties should be planted in the wheat areas around the summer areas such as Longnan Mountain and Liupanshan. Other areas in the northwest wheat region try to select local varieties with high quality, disease resistance and high yield according to the situation.

(3) seed dressing with chemicals. According to the situation of diseases and pests, high efficiency suspension seed coating agents such as tebuconazole, difenoconazole, pyronitrile and difenoconazole were used for wheat seed coating to prevent diseases, and appropriate amount of imidacloprid suspension seed coating agent was used to prevent pests, yellow dwarf disease and bushy dwarf disease. the mixture of the two can treat the main diseases and insect pests at seedling stage. In the summer area of stripe rust and its surrounding wheat areas, seed dressing agents such as triadimefon and tebuconazole were used to treat stripe rust and powdery mildew in seedling stage and prevent the occurrence of fishy smut in the later stage. In the total erosion disease occurrence area, difenoconazole suspension seed coating agent and silothiazide (total erosion net) suspension agent are mainly used to mix or coat seeds; phoxim or chlorpyrifos can be used for underground pests; soil treatment should be carried out in fields where soil-borne diseases and underground pests are particularly serious. In the mixed occurrence area of many kinds of diseases and pests, the seed coating agent or seed mixing agent combined with fungicides and pesticides can be used for coating or seed treatment according to the main local diseases and insect pests. The effective components of each single agent in the compound (mixed) agent should be roughly the same as when used alone. In the areas where aphids, wheat spiders and underground pests were seriously damaged at seedling stage, phoxim or imidacloprid suspension seed coating agents were used to treat seeds.

(4) Agricultural measures. In the area where corn straw is returned to the field in Huang-Huai wheat region, it is necessary to make fine soil preparation, bury corn straw in the soil as far as possible, clean up the residual stalks of seedlings, and combine winter irrigation and suppression of wheat seedlings after emergence. In the areas or fields where cyst nematode disease occurs seriously, we should focus on popularizing the measures of suppressing and controlling the disease after sowing and autumn seedling stage. In the oversummer area of wheat stripe rust, the self-growing wheat seedlings should be removed by manual eradication and spraying herbicides, and late sowing should be adopted during sowing period according to soil moisture, so as to reduce the infection of stripe rust in seedling stage, reduce the disease in seedling stage and depress the bacterial source of autumn seedlings.

(5) Prevention and control of autumn seedlings. According to the incidence of autumn seedlings such as stripe rust, powdery mildew and sheath blight, noodle preservation was carried out when the disease was serious. In southern Shaanxi, where stripe rust flourishes in winter, monitoring should be strengthened and chemical control should be carried out in the field of early disease. triazole fungicides can be used for spray control. In the areas where sheath blight occurs at the seedling stage, monitoring should be strengthened and control should be carried out as early as possible; on the basis of seed dressing and prevention, attention should be paid to the prevention and control of aphids at seedling stage in Weibei Arid Plateau, Longdong area of Gansu Province, Longnan area of Gansu Province and winter wheat area of southern Ningxia. Prevent the occurrence of wheat yellow dwarf disease. Early winged aphids can be trapped and killed by yellow board, and insecticides with high efficiency and low toxicity such as imidacloprid and imidacloprid can be used for control.

National Agricultural Technology extension Service Center

National Wheat Industry system Disease and Pest Prevention and Control function Laboratory

September 25, 2015