According to the National Agricultural Technology Center, the provincial and district (city, city) forecasting and technical personnel and relevant experts will discuss the combination of rice pests and diseases, cultivation system, rice varieties, winter and spring climatic conditions and other factors. It is expected that rice pests and diseases will be biased in 2018. The ecological potential is heavier than that of the previous year, with an area of ​​1.32 billion mu. Among them, the area of ​​insect pests was 900 million mu, and the area of ​​disease occurrence was 420 million mu.
Occurrence characteristics: First, the area of ​​rice planthopper and rice leaf roller is wide, and the rice areas in South China, Jiangnan and the middle and lower reaches of the Yangtze River are heavily biased. Second, the stem borer has a significant upward trend in most rice areas, and the middle reaches of the Yangtze River and the Yangtze River. The recurrence situation is obvious in the area; the third is that the rice blast disease has a high prevalence risk in the southwest, the south of the Yangtze River, the middle and lower reaches of the Yangtze River and the northeastern part of the rice. The southern rice black-streaked dwarf disease has a recurrence risk in the southern part of the rice.
First, the trend
(1) Pests
Rice planthoppers occur in southern China, Jiangnan, the middle and lower reaches of the Yangtze River and parts of the southwestern part of the Yangtze River. Other rice areas occur moderately, with an area of ​​380 million mu. The rice leaf roller is generally moderate, with some rice areas in the lower reaches of the Yangtze River and parts of the south of the Yangtze River occurring, with an area of ​​230 million mu.
In most rice areas, stem borer showed a trend of resurgence, with overall emphasis on it. Among them, most of the rice areas in the middle reaches of the Yangtze River and the middle reaches of the Yangtze River occurred in large areas, and some rice areas occurred in large areas, including northern China, northwestern China and Jianghuai, with an area of ​​220 million mu. . The total occurrence of Sanhua carp is relatively light, occurring in southern South China and northwestern China, with an area of ​​20 million mu.
(2) Diseases
Rice sheath blight is generally biased, with the middle reaches of the Yangtze River occurring locally, and most of the northeast and southwestern regions occur moderately, with an area of ​​260 million mu. Rice blast is generally moderate, with a high prevalence risk in the southwestern part of the country, south of the south of the Yangtze River, the middle and lower reaches of the Yangtze River and the northeastern part of the country, with an area of ​​75 million mu. The rice smut was generally mild to moderate, and the middle and late rice in the south of the Yangtze River and the middle and lower reaches of the Yangtze River were partially heavier, with an area of ​​45 million mu. Rice virus disease is generally mild, with an area of ​​10 million mu. The southern rice black-streaked dwarf disease has a recurrence risk in southern China and Jiangnan.
Second, the basis of prediction
(1) The number of pests and diseases
The area and base of overwintering insects in the winter before the winter is higher. The national insect source area increased by 6.4% and 14.1% respectively compared with the same period of 2016 and the past five years. The average live insect per mu increased compared with 2016 and the same period of the past five years. 58.3% and 15.3%, of which the number of live insects in the Jiangnan rice area and the middle reaches of the Yangtze River is as high as 4000-9000 heads and 2200-3000 heads respectively, with the base number of insects occurring above the weight;
The winter and spring temperatures of the "two-shifted" pests outside the insects are high, which is conducive to the accumulation of insects in winter and spring. According to the statistics of the Vietnam Plant Protection Bureau, the area of ​​southern rice black-streaked dwarf disease increased sharply in northern Vietnam in 2017, close to the year of re-issue in 2010, with a prevailing source of poison. Diseases such as rice blast, rice false smut, and rice sheath blight are accumulating in the Changfa area due to the accumulation of bacterial sources, and the amount of bacteria in the field is large, which has a bacterial source base of moderate to above occurrence.
(2) Farming system
At present, the main rice producing areas in the country are mainly planted with thick stalks and large-leaf varieties, high-quality and high-yield varieties, which are easy to form a moderate and high-humidity field microclimate, which is conducive to the occurrence of rice pests and diseases. The disease resistance of the main varieties is uneven, and the disease-resistant varieties have a low proportion in the field, and the resistance of some varieties is degraded or lost, which is conducive to the occurrence of diseases such as rice blast and rice smut.
The mixed area of ​​single and double-season rice in the southern rice area is large, and there are many bridges and fields, which is conducive to the damage of rice pests such as pests and aphids. In addition, although the straw cutting and natural returning methods are beneficial to increase soil organic matter and fertility, it is also conducive to the accumulation of insect sources, bacterial bases and the increase of pests and diseases.
(3) Meteorological conditions
According to the prediction of the National Climate Center, in the winter of 2017, the country is characterized by high temperature and low precipitation in the north. The temperature and humidity conditions are suitable for the wintering of aphids, rice sheath blight, rice blast and other pests in the main rice producing areas of southern China; 2018 In spring, most of the country's temperature is high, and precipitation is relatively low. Among them, southern Zhejiang, southwestern Jiangxi, southeastern Hunan, Fujian, and Guangdong are less than 2-5 percent, which is beneficial to the occurrence of rice aphids.
This article URL: 2018 national rice major pests and diseases are biased, the risk of migratory epidemics is high.
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