Major diseases and pests of autumn grain crops have entered a peak period.

At present, it is a critical season for the growth of autumn grain crops such as rice, corn and potatoes. According to the monitoring of the national network for major crop diseases and pests, many kinds of diseases and pests, such as rice "two-migration" pests, rice blast, corn borer, potato late blight, and so on, are increasing rapidly, and the damage degree is gradually increasing.

The occurrence base of rice diseases and insect pests was high, and the recurrence trend was obvious in the later stage. So far, a total of 575 million mu of major rice diseases and insect pests have occurred, an increase of 86 per cent over the beginning of July. Among them, the occurrence of rice planthopper was 163 million mu, which was significantly more serious than that of the previous year. The occurrence of rice leaf roller is 118 million mu, which is the same as that of the same period last year. The occurrence of rice blast is 24 million mu, and the rate of diseased leaves in southern rice areas is generally 2% to 5%, but the phenomenon of re-occurrence is prominent. At present, the rate of diseased leaves in northeast rice region is relatively low, generally less than 2%, but the number of diseased spots has increased rapidly recently. It is expected that in the next stage, rice "two migration" pests in the south of the Yangtze River and the middle and lower reaches of the Yangtze River, as well as the recurrence of rice blast in the eastern part of the southwest, the middle and lower reaches of the Yangtze River and the northeast are obvious.

The occurrence range of maize diseases and insect pests is wide, and the local damage is aggravated. So far, a total of 450 million mu of major corn diseases and insect pests have occurred, an increase of 6% over the same period last year and 73.1% more than in early July. Among them, the occurrence of corn borer was 110 million mu, and the occurrence of corn borer was moderate to heavy in the northeast spring corn area, which was the same as that of the previous year. The rising harm trend of spring corn area in northwest China is obvious. The overall occurrence in Huang-Huai-Hai summer corn area was moderate, but the local degree was serious. Corn leaf spot occurred 65 million times per mu. Corn armyworm appeared adult peaks in Northeast North China and Huang-Huai in late July especially the number of moths in Northeast China was significantly higher than that in the same period last year and the larval damage would enter the peak period in the first and middle of August. It is expected that in the next stage, the occurrence of corn borer will be more serious in the south of Northeast China, North China, Huang-Huai and Xinjiang, the epidemic of corn leaf spot will be aggravated in some parts of Northeast China, and the third-generation armyworm will show high density and concentrated damage in Northeast, North China and Huang-Huai.

The recent expansion of potato late blight is accelerated, and the risk of recurrence is higher in the later stage. Affected by the lack of precipitation in the previous period, the occurrence of late blight in the main potato producing areas in North, Northwest and Northeast China was lighter than that in the same period last year, with a total occurrence of 5.1 million mu, a decrease of 29.1% over the same period last year. However, with the increase of Rain Water in the flood season, the recent expansion rate has obviously accelerated, and the local area of Northeast and Northwest has increased rapidly. It is expected that the next stage will enter the peak period of epidemic, and there is a high risk of recurrence in southern Gansu, western Heilongjiang, eastern Inner Mongolia, northern Shanxi and northern Hebei.

In view of the grim situation of the occurrence of major diseases and pests in 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 Prevention and Control of Diseases and pests for Autumn Grain," conscientiously implement the spirit of the national on-the-spot meeting on the prevention and control of major diseases and pests of autumn grain crops, strengthen the implementation of measures, and strive to achieve "pest control."