In 2021, the projected area affected by Class I pests and diseases nationwide is 1.428 billion mu, showing a trend of severe recurrence.

In early 2020, the Regulations on the Prevention and Control of Crop Pests and Diseases were officially implemented, establishing a classification system for pest and disease severity. Recently, the National Agricultural Technology Extension Center issued its forecast for the 2021 national trends in major crop pests and diseases, predicting that Category I pests and diseases will experience a resurgence, with an estimated affected area of 1.428 billion mu‑times—up 17.5% year on year.

In 2021, rice pests infested a wide area, with brown planthopper outbreaks covering 350 million mu‑times. Overall, the southern rice-growing regions experienced relatively severe infestations, while the central and eastern parts of the Jiangnan region saw large-scale outbreaks. Specifically, the whitebacked planthopper was severely prevalent in western South China, eastern Southwest China, the middle reaches of the Yangtze River, and the Jiangnan rice areas, and moderately prevalent in eastern South China, western Southwest China, the lower Yangtze River, and the Jianghuai rice region. The brown planthopper was severely prevalent across most of South China, eastern Southwest China, Jiangnan, the middle and lower Yangtze River, and the Jianghuai rice region, with particularly large outbreaks in the central and eastern Jiangnan rice areas.

The rice leafroller has occurred across 240 million mu‑times nationwide, with severe outbreaks in the eastern Southwest, South China, the Jiangnan region, the middle and lower reaches of the Yangtze River, and the Jianghuai rice-growing area, while moderate outbreaks have been observed in the western Southwest. The rice stem borer has affected 210 million mu‑times nationwide. Overall, the central and eastern rice-growing areas of southern China have experienced moderate infestations, with severe outbreaks in the Jiangnan region, the northern parts of the Southwest, and the middle reaches of the Yangtze River; particularly heavy outbreaks have been reported in south-central Hunan, northern Jiangxi, and the eastern coastal areas of Zhejiang.

The fall armyworm is a major migratory pest that invaded China in 2019. According to forecasts by the National Agricultural Machinery Center, in 2021 the area affected nationwide will reach 40 million mu‑times. The infestation covers maize‑growing regions from the Huanghuaihai Plain southward, with 80% of the affected area concentrated south of the Yangtze River. Among these areas, the Southwest and South China will experience multiple generations and severe outbreaks; the Jiangnan region and the middle and lower reaches of the Yangtze River may see moderate outbreaks; the Jianghuai, Huanghuai, Northwest, and North China regions will face lighter or lower‑level outbreaks; and the southern part of Northeast China may experience sporadic occurrences. Locusts and other migratory locust species are expected to infest 33 million mu‑times, with the yellow-spined bamboo locust posing an invasion risk along the Yunnan border, and the desert locust potentially re‑invading China’s Tibetan border. The grass webworm is projected to affect 30 million mu‑times.

The nationwide area affected by armyworms is projected to reach 75 million mu‑times, with corn armyworms accounting for over 80% of this total. The area infested by wheat aphids is expected to amount to 200 million mu‑times, while the potato beetle is anticipated to occur across 100,000 mu‑times nationwide, and the codling moth is projected to affect 600,000 mu‑times.

According to forecasts from the National Agricultural Technology Extension Center, the nationwide area affected by rice blast is expected to reach 65 million mu‑times. In frequently affected regions—including the hilly and mountainous areas of Southwest China and the Jiangnan region, along the Yangtze and Huai Rivers, and in the major production areas of Northeast China—the risk of severe outbreaks is high, while other rice-growing areas face moderate incidence. As for southern rice black-streaked dwarf disease, the national affected area is projected at 3 million mu‑times. Moderate outbreaks are anticipated in localized rice-growing areas of northern South China, eastern Southwest China, and central Jiangnan, with most other southern rice-growing regions experiencing only mild incidence.

The national area affected by citrus Huanglongbing (HLB) totals 2.2 million mu. In most of South China and the southern Jiangnan citrus‑growing regions, the incidence is generally moderate, with a potential for severe outbreaks in localized areas. In much of Yunnan and in certain citrus orchards in southern Sichuan and Guizhou, the disease has occurred in patchy outbreaks, posing a risk of further spread to western Hunan, central Jiangxi, and southeastern Sichuan.

Wheat stripe rust is expected to affect 60 million mu nationwide, wheat scab 90 million mu, potato late blight 28 million mu, and fire blight of pears 750,000 mu. The National Agricultural Technology Extension Center has urged that, in light of the resurgence of Class I crop diseases and pests in 2021, plant protection agencies at all levels must earnestly assume local responsibility, strengthen monitoring and forecasting, vigorously implement preventive and control measures, and intensify technical guidance services, thereby fully supporting efforts to safeguard grain production and ensure a bountiful harvest.

Source: Agricultural Finance Network