Wheat scab is an important epidemic disease in the middle and lower reaches of the Yangtze River in China. In recent years, it has also increased in the Huanghuai wheat area of â€‹â€‹China. The occurrence and prevalence of the disease are affected by various factors such as climate, overwintering bacteria, host growth period, and variety resistance. During the autumn sowing period, the cultivation measures such as rational selection of disease-resistant varieties and deep burying of straw to reduce bacterial sources are beneficial to reduce the pressure of chemical control of wheat mildew in the late growth stage.
It is understood that this year, the wheat heading and flowering period in Jiangsu Province is more sunny and less rainy, which has inhibited the occurrence of wheat scab in the south of the Huaihe River, and the previous precipitation areas have not coincided with the large area of â€‹â€‹the heading flowering area, reducing the strain of Gibberella The risk of disease is also conducive to the prevention and control of wheat scab. The incidence period is the latest in recent years, and the incidence is also the lightest year in recent years. However, in Huaibei area, there are still a few fields that have caused recurrence of scab due to the selection of susceptible varieties in other provinces, and eventually caused certain losses.
Some experts said that in recent years, wheat scab in Jiangsu Province has generally shown a trend of expanding to the north, and its incentives have a lot to do with susceptibility to disease. Compared with the Huainan area, most of the varieties applied in the northern part of Jiangsu Province have poor resistance to scab, which is characterized by susceptibility or moderate sensation, while the varieties introduced from northern provinces such as Shandong and Henan are less resistant to scab. The performance is high, and the disease index can rise rapidly in a short period of time when the climatic conditions are favorable for the onset. Therefore, the utilization and rational layout of resistant varieties is the basis for the prevention and control of wheat scab. At present, although there is no wheat variety with high resistance to scab, there is a big difference in disease resistance between varieties. According to the application situation in recent years, the varieties with better resistance to scab are Ningmai 13, Yangmai 21, Zhenmai No. 10, Huamai No. 7, Yangjimai No. 4, etc., which can be applied in the northern region. There are fewer varieties resistant to disease, and some varieties of Huaimai and Zhengmai 9023 have relatively good resistance.
Changes in cultivation methods have a greater impact on the occurrence of wheat scab. Some investigations have shown that the operation of straw returning to the field is extensive, so that a large amount of unbleached straw remains on the surface of the soil, which is conducive to the spore production of the scab pathogen and increases the bacterial source. At the same time, in recent years, the wheat planting period in Jiangsu Province has been generally postponed. In order to increase the yield, farmers usually increase the seeding rate, which makes the population density high, and the field is highly concealed. In the later stage, it is easy to form high temperature, high humidity, depression, and disease infestation. The prevailing field microclimate conditions have greatly increased the prevalence and severity of scab.
To accelerate the decomposition of straw and soil surface to reduce the residual straw Plant Protection, Jiangsu Academy of Agricultural Sciences researcher has proposed Huai valley, wheat scab incidence and prevalence areas should be implemented straw buried by plowing the soil to bury Straw Below 20 cm of soil. After ploughing, the corresponding suppression treatment is carried out to accelerate the maturity of the straw and reduce the growth of the bacteria. Conditional areas promote the utilization of straw resources, reduce the breeding matrix of pathogens in the field, and reduce the amount of bacteria.
In addition, it is necessary to adhere to the appropriate sowing, avoid late planting, reduce the probability of high temperature and rainy weather during wheat heading and flowering period; avoid the planting of wheat varieties in different growth stages, so that the wheat growth process is neat and consistent, which is convenient for centralized drug control; The quantity should be reasonable, avoid blindly increasing the amount of seeds used for late sowing, and ensure the appropriate number of groups in the middle and late stages of wheat; the supporting work of the ditch should be done in the wheat field to ensure smooth irrigation and drainage, and maintain low-humidity in the late growth stage.
More pesticide encyclopedia, please pay attention to China Pesticide Network
(Source: Pesticide Newsletter)
Guangdong Jia Mei Biological Technology Co.Ltd , https://www.jaymeimask.com