Major pests and diseases of autumn grain crops enter the peak outbreak period

At present, it is precisely the critical period for the growth of autumn grain crops such as rice, corn and potatoes. According to monitoring by the National Crop Major Pest and Disease Forecasting Network, many pests and diseases such as the rice “two migration” pests, rice blast, corn borer and potato late blight are showing a trend of rapidly increasing occurrence area and gradually worsening damage.

The occurrence base of rice pests and diseases is high, and the trend of severe recurrence in the later period is obvious. As of now, the cumulative occurrence of major rice pests and diseases has reached 575 million mu-times, an increase of 86% over early July. Among them, the brown planthopper occurred on 163 million mu-times, with severity noticeably greater than the previous year. The rice leaf roller occurred on 118 million mu, with severity comparable to the same period last year. Rice blast occurred on 24 million mu-times; in the southern rice region the diseased leaf rate is generally 2%-5%, but severe occurrences in spots and patches are prominent. In the northeastern rice region the current diseased leaf rate is relatively low, generally below 2%, but disease spots have recently increased rapidly. It is expected that in the next stage the rice “two migration” pests in Jiangnan and the middle and lower reaches of the Yangtze River, as well as rice blast in eastern Southwest China, the middle and lower reaches of the Yangtze River and the northeastern rice region, will show an obvious trend of severe recurrence.

⟦NL> Corn pests and diseases occur over a wide range, with locally worsening damage. As of now, the cumulative occurrence of major corn pests and diseases has reached 450 million mu-times, an increase of 6% year-on-year and an increase of 73.1% over early July. Among them, the corn borer occurred on 110 million mu-times; in the northeastern spring corn region it is generally moderate to relatively severe, with severity comparable to the previous year. In the northwestern spring corn region the damage trend is obviously rising. In the Huang-Huai-Hai summer corn region it is generally moderate, but locally relatively severe. Corn northern leaf blight occurred on 65 million mu-times. For corn armyworm, adult peaks appeared successively in Northeast, North China and Huang-Huai regions in late July, with moth numbers in Northeast China notably higher than the same period last year; in early to mid-August it will enter the peak period of larval damage. It is expected that in the next stage the corn borer will occur relatively severely in southern Northeast China, parts of North China and Huang-Huai, and Xinjiang; corn northern leaf blight will intensify and spread in parts of Northeast China; and the third generation of corn armyworm will cause high-density concentrated damage in parts of Northeast, North China and Huang-Huai.

Potato late blight has recently expanded faster, with a relatively high risk of severe recurrence in the later period. Affected by relatively low precipitation earlier, late blight in the main potato production areas of North China, Northwest China and Northeast China was lighter than the same period last year, with cumulative occurrence of 5.1 million mu, a decrease of 29.1% year-on-year. However, as rainfall increases during the flood season, the expansion rate has recently accelerated noticeably, and the occurrence area in parts of Northeast and Northwest China has risen rapidly. It is expected that the next stage will enter the peak period of occurrence and epidemic, with relatively high risk of severe epidemic in southern Gansu, western Heilongjiang, eastern Inner Mongolia, northern Shanxi and northern Hebei.

In response to the severe situation of major pests and diseases harming autumn grain crops, agricultural departments and plant protection agencies at all levels, in accordance with the overall requirements of the Ministry of Agriculture's "Action Plan for Preventing Diseases and Controlling Pests to Secure an Autumn Grain Harvest," earnestly implement the spirit of the national on-site meeting on prevention and control of major pests and diseases of autumn grain crops, strengthen the implementation of measures, and strive to achieve “seizing grain from the mouths of pests.”