A total of 74.57 million mu have been affected! The major diseases and pests of early-spring wheat include the following:

Release Date:

2020-03-08

Currently, the Southwest Wheat Region Wheat Most areas are in the jointing–booting stage, with the Han River basin and most of the Huanghuai region at the green-up–jointing stage. In the North China and Northwest wheat-growing regions, green-up is occurring successively, and in most wheat-growing areas, the growing season is advancing compared with the long-term average.
As of March 4, Wheat The cumulative area affected by major diseases and pests—including stripe rust, sheath blight, wheat spider mites, aphids, and powdery mildew—reached 74.57 million mu, an increase of 22.9% year on year. Stripe rust has spread widely, with rapid dissemination and severe disease incidence in the southwestern region, the Han River basin, and the southern Huanghuai wheat-growing area. Sheath blight emerged early in the Huanghuai wheat region, while wheat spider mites have reached high population levels in the northern Hubei hilly areas and in localized zones within the Huanghuai wheat region.
Recent Developments
Stripe rust has broken out across 208 counties (cities, districts) in 54 cities spanning eight provinces (municipalities) in the Southwest, the Han River Basin, and the southern Huanghuai wheat-growing region, affecting 3.926 million mu. Compared with last week, this represents an increase of four cities, twelve counties, and 65.3% in affected area; the total affected area is up 53.9% from the same period in 2017, marking the largest outbreak since 2011.
In the wheat-growing regions of Southwest China and the Han River Basin, the disease has entered a phase of rapid spread and is occurring fairly widely. In most of Southwest China, the average incidence of diseased leaves ranges from 1.4% to 3.6%, while in the Han River Basin it stands at 0.2% to 0.5%. Local outbreaks are relatively severe: in southern Hubei, the proportion of infected fields approaches 50%, and in southern Shaanxi—particularly in Ningqiang and other areas—the local infection rate exceeds 60%. In heavily affected fields, symptoms are now widespread; in certain plots in Chengjiang (Yunnan), Nayong (Guizhou), Zitong (Sichuan), and other locales, the highest recorded incidence of diseased leaves surpasses 60%.
In the southern Huanghuai wheat-growing region, the number of disease foci has increased. In Nanyang, Henan, more than 150 disease foci were detected across nine counties (cities and districts), with an average incidence rate of 2.3% in affected fields and a disease severity ranging from 5% to 60% on infected leaves. In the Northwest wheat-growing region, sporadic cases were observed in two counties in Longnan, Gansu.
Blight disease has affected 31.31 million mu across 10 provinces, autonomous regions, and municipalities in the Huanghuai, Southwest, and North China wheat-growing areas, roughly unchanged from last year. In key epidemic zones along the Huai River and in northern Huai, symptoms appeared earlier than usual, with average incidence rates ranging from 3% to 7.2%. In the North China wheat region, outbreaks have been sporadic, with average incidence rates of 1.2% to 1.8%, higher than at the same time last year. In localized severely affected fields in Huaiyin and Jinhu in Jiangsu, Zhongxian in Chongqing, Xincai in Henan, and Zhengding in Hebei, peak incidence rates have reached 20% to 65%.
Powdery mildew has affected 1.76 million mu across nine provinces, autonomous regions, and municipalities in the Southwest, Huanghuai, Jianghuai, and North China wheat-growing areas, an increase of 54.6% year on year. In the Southwest wheat region, the average disease‑leaf rate generally ranges from 8% to 11%, while sporadic cases have been observed in the Huanghuai and North China regions, with average rates of 0.2% to 2%. Localized outbreaks have been relatively severe in Zhong County, Chongqing; Nayong, Guizhou; and Binzhou, Shaanxi, where peak disease‑leaf rates reached 30% to 45%; in certain fields in Chengjiang, Yunnan, the highest disease‑leaf rate exceeded 90%.
Wheat spider mites have infested 27.03 million mu across 10 provinces, autonomous regions, and municipalities in the Yellow–Huai, Jianghuai, Southwest, and North China wheat-growing areas, a 34.1% increase year on year. Local pest densities are relatively high, exceeding typical levels for this time of year.
In the Huanghuai, Jianghuai, and Southwest wheat-growing regions, the average pest density is typically 10–50 insects per hundred feet of row; in localized areas such as Nanyang, Xinyang, Luohe, and Zhumadian in Henan, peak densities have reached as high as 3,000 insects, while in Yicheng, Hubei, they have peaked at 8,000. In the North China wheat-growing region, the average pest density is generally 8–8.4 insects per hundred feet of row, with peak densities ranging from 150 to 400 insects in Yicheng, Shanxi, and Xingtang, Hebei.
Aphids have infested 10.4 million mu across 11 provinces, autonomous regions, and municipalities in wheat-growing areas including Southwest China, the Huanghuai Plain, and the Jianghuai region, an increase of 55.9% year on year.
In the Southwest wheat-growing region, aphid infestations were fairly widespread, with an average of 80–168 aphids per 100 plants; in some heavily reinfested fields in Chengjiang, Yunnan, peak densities reached as high as 6,500 aphids per 100 plants. In the Huanghuai and Jianghuai wheat regions, the average number of aphids per 100 plants ranged from 3.8 to 13.8, with many areas experiencing higher levels than during the same period last year. In localized reinfested fields in Yichang, Hubei; Yancheng, Jiangsu; and Xinyang, Henan, aphid populations ranged from 800 to 1,500 per 100 plants.
Stem base rot has occurred sporadically in wheat-growing regions such as the Huanghuai area, with localized outbreaks reported in places like Heze, Shandong; the incidence of affected plants generally ranges from 2% to 10%, higher than at the same time in recent years. Snow mold and snow blight have appeared earlier than usual in northern Xinjiang, with an average incidence of 0.6% to 12%; in severely affected fields, the proportion of infected plants reaches as high as 50%. Overall, root rot, yellow mosaic disease, leaf rust, and other pests and diseases have been observed at low levels.
Development Trends
According to forecasts from the National Climate Center, in March, most wheat-growing regions are expected to experience above-normal temperatures and above-normal precipitation. Specifically, the North China, Huanghuai, and Jianghuai wheat-growing areas will see temperatures 1–2°C higher than average, while northern Shaanxi, Ningxia, northeastern Gansu, eastern Hubei, most of Guizhou, and southeastern Chongqing will receive 20%–50% more rainfall, which is favorable for… Wheat Stripe rust, aphids, and other pests and diseases are spreading.
As temperatures rise, stripe rust is spreading rapidly in the wheat-growing regions of Southwest China and the Han River Basin, with an increasing number of disease foci reported in the southern Huang-Huai wheat area. Meanwhile, wheat spider mites, aphids, and sheath blight are becoming more prevalent in the Huang-Huai and Jianghuai wheat areas; therefore, monitoring should be intensified, and timely control measures implemented.