Protracted war on 1.8 billion acres of farmland by insects

  In April 2021, in Taizhuang Village, Xutang Township, Funan County, Anhui Province, farmer Liu Xiangqian found scattered yellow-streaked wheat leaves in his wheat field. This is a symptom of wheat stripe rust.

  Farmers who have been farming for many years are extremely sensitive to this disease that may cause huge losses to wheat, but as long as they are found, the corresponding prevention and control methods are very familiar, and within a short period of time, hundreds of acres of wheat are all given the medicine.

The alarm sounded and the scope of action expanded rapidly. In the wider field, agricultural technicians from cities, counties, and townships entered the wheat fields one after another to investigate the incidence of stripe rust, and guide farmers to prevent and cure them. At that time, rural fields In the sky, flying plant protection drones can be seen everywhere.

  In early December 2021, Liu Xiangqian told reporters that stripe rust had a major outbreak this summer, but it was discovered early and prevented early, and almost no losses were caused. He hoped that this good momentum would continue in 2022.

  60 million tons of grain a year "out of danger"

  Including multiple cropping, the country’s annual sown area exceeds 2 billion mu, of which grain sown area accounts for the vast majority.

According to data from the National Bureau of Statistics, my country's grain sown area will exceed 1.75 billion mu in 2020, which has become the most important basis for ensuring my country's food security.

  Another important part of ensuring food security is the prevention and control of pests and diseases.

In September 2020, my country announced 17 first-class crop diseases and insect pests. Most of the pathogens and pests are the three main staple foods of wheat, rice and corn.

  In wheat, stripe rust, head blight, and aphids are a class of major pest control targets.

Spodoptera exigua, which has invaded China in recent years, has posed a serious threat to corn.

Among the rice, the northern rice mainly faces the damage of rice blast, and the southern rice also has pests such as rice planthopper, rice leaf roller, and Chinese rice borer.

  In the fight against pests and diseases, whether they can gain the upper hand directly affects the annual harvest.

  These pests and diseases do not occur every year. In 2021, we will fight against wheat stripe rust, Spodoptera frugiperda, southern corn rust, rice leaf roller, etc., as well as the frequent occurrence of wheat aphids. .

  A set of data from the National Agricultural Technology Extension Center shows that in the past 10 years, the average annual area of ​​rice diseases and insect pests in my country has been more than 1.2 billion mu, and the area where control measures have been taken is more than 1.9 billion mu.

In wheat, the average annual occurrence area is more than 800 million mu, the prevention area is more than 1.1 billion mu, the average annual occurrence area of ​​corn is more than 700 million mu, and the prevention area is more than 640 million mu.

  It is worth noting that the losses caused by pests and diseases cannot be completely avoided, as long as they happen, there will be losses.

However, prevention and control measures that cover a large area and have obvious effects can minimize losses.

Data from the same source shows that through the implementation of effective pest control, nearly 60 million tons of output loss can be recovered every year among the three main staple foods. Even so, there are still nearly 12 million tons of actual losses.

  What is the concept of 60 million tons of grain "out of danger"?

In 2021, Henan Province's grain output is second only to Heilongjiang, ranking second in the country, reaching 65.44 million tons.

We have retaken almost all of the harvest from the second largest province in the country.

  Spodoptera frugiperda's expansion road blocked

  In July 2021, in a farm in Xuzhou, Jiangsu, several agricultural technicians are giving technical guidance to growers.

There are obvious wormholes in the corn leaves in the field. “This is a typical symptom of corn borer. It can be controlled by spraying chlorantraniliprole and emamectin benzoate with drones.”

  Corn borer is an important pest of corn. Although it is not included in the country's 17 first-class pests, it is listed as local second-class pests in many places.

In 2021, corn borer occurred in many places. A pest information released by the Funan County Plant Protection Plant Inspection Station in Anhui on July 14 showed that the local spring corn first corn borer field rate was 100%, and the average damaged plant rate was 4.76%, the highest 8%, the amount of insects under the lights was higher than the same period last year, and the overall incidence was moderate to light, with an estimated area of ​​300,000 mu.

The pest forecast also lists control methods and precautions in different periods.

  At the same time, a pest information from Jiangsu Rugao Agricultural Technology Extension Center not only announced the situation of corn borer, but also the situation of another "ace" pest-Spodoptera frugiperda.

  Intelligence showed that the local monitoring point "attracted 1 adult on May 25, and started seeing adults again on July 8, and automatically reported a total of 42 moths from July 8 to August 3."

  Spodoptera frugiperda, the pest that invaded our country in 2019, has rapidly invaded, settled, and migrated north in the spring in more than two years, becoming one of the major agricultural pests that are attracting public attention.

  As an alien species, due to the lack of natural enemy control at the beginning of the invasion, once settled and reproduced, the damage may be greater than the original place of origin.

Wang Zhenying, director of the National Corn Industry Technology System Research Office for Diseases, Pests and Weeds Prevention and Control, and a researcher at the Institute of Plant Protection of the Chinese Academy of Agricultural Sciences, told reporters that in response to the invasion of Spodoptera frugiperda, my country has established a complete monitoring system to comprehensively and systematically monitor the occurrence of Spodoptera frugiperda Dynamically, the Ministry of Agriculture and Rural Affairs has also formulated a "three zones and four belts" deployment plan, which is deployed layer by layer to slow the northward migration of grassland armyworms and minimize the pressure on the main corn producing areas.

  Wang Zhenying revealed that at present, my country has a set of monitoring and early warning systems and comprehensive prevention and control technologies for Spodoptera frugiperda, which can effectively prevent and control the damage of Spodoptera frugiperda.

In 2021, Spodoptera frugiperda mainly damages corn areas in the southwest and south. Huanghuaihai and northern spring corn areas have a small area of ​​damage. Due to timely prevention and control, the impact on yield is small.

Public data also shows that up to now, Spodoptera frugiperda is still under control in the south of the Yangtze River, and its damage is within 3%.

  After the stripe rust outbreak

  It is a complete set of monitoring and control systems that control the grassland spodoptera.

For example, disease and insect forecasting, this is a set of monitoring, bottom-up reporting, and top-down arrangement of prevention and control methods by plant protection stations distributed across the country. There are usually different forms of long-term, medium- and short-term issuance of forecasts, which almost cover All the growth stages of crops.

  On March 9, 2021, Xichuan County, Henan Province issued pest information and issued an alert for wheat stripe rust. The alert showed that stripe rust was first discovered in the new wheat growing season in November 2020, which is the second morning in history. It has attracted extensive attention from all regions and departments.

  This is confirmed by Liu Taiguo, a researcher at the Institute of Plant Protection of the Chinese Academy of Agricultural Sciences and executive chief of the Crop Fungal Disease Epidemic and Prevention and Control Innovation Team.

He told the Beijing News reporter that following the pandemic of stripe rust in 2020, wheat stripe rust will become epidemic again in 2021, with early onset, large area, and sufficient bacteria, which has caused serious threats to the main wheat-producing provinces of Huanghuaihai and the severe disease. The degree is also rare in recent years.

  Liu Taiguo said that the serious prevalence of stripe rust can be predicted by the source of stripe rust on volunteer wheat seedlings in autumn in Gansu and Sichuan.

Every autumn and winter, the Plant Protection Institute of the Chinese Academy of Agricultural Sciences, together with the National Agricultural Technology Extension Service Center and other units plant protection technicians, conduct a unified investigation of the source of the bacteria, from southern Gansu, northwest Sichuan, to northwest Hubei, southern Henan and other wheat stripe rust pathogens Source base investigation and judgment, combined with meteorological conditions, variety planting information and other factors, can basically judge the prevalence and basic trend of the disease in the coming year, combined with the information debugging of the National Agricultural Technology Extension Center’s forecast and control system, the Ministry of Agriculture and Rural Affairs will The occurrence trend of diseases and insect pests shall be notified to relevant units so that all localities can do a good job of summer grain production in advance.

  These measures undoubtedly played a key role.

Liu Taiguo introduced that in April 2021, which is the peak period of stripe rust disease, he conducted investigations in various places, "Starting from Beijing, passing through Hebei, Henan, Anhui, and then to Shandong, the investigation was carried out in a circle, except for the late wheat growth period in Hebei. In addition to wheat stripe rust, single diseased leaves or disease centers can be seen in other places passing by, especially in Henan. Disease points can be found in any piece of land, which shows that stripe rust has begun to prevail."

  However, Henan, where stripe rust occurred the most, suffered the least damage.

Liu Taiguo told reporters that this is directly related to the early prevention and treatment. “When I was in Henan, I saw that most of the wheat fields had been treated with medicine. Although the disease spots of stripe rust were visible, the bacteria had been basically killed. At that time, the cadres of the agricultural departments in various places were in the field to guide the prevention and control during that time, and the province also advanced funds and allocated special funds for prevention and control to ensure a good summer grain harvest in the country."

  Wheat stripe rust is a major epidemic disease of wheat. Pay close attention to the key period of prevention and control. It is directly related to the result of "graining by insects". If the control window period is missed, yield loss will basically take place, and the control effect will be great. discount.

  Confrontation in the micro world

  Whether it is stripe rust or Spodoptera frugiperda, fighting against pests and diseases is the eternal theme of human agriculture.

  Wang Zhenying told reporters that only for the three major staple foods, there are hundreds of pests and diseases that each crop may encounter, and in reality, there are dozens of types that may cause yield loss.

  The prevention and control of every kind of disease or pest requires the hard work of countless scientists.

What's more troublesome is that pests, viruses, and fungi are also fighting against humans and constantly evolving.

  Take stripe rust as an example. Its "base camp" is in Gansu and Sichuan, especially the Longnan area of ​​Gansu and the northern Sichuan area of ​​Sichuan. It is called the "source base" of stripe rust, where there is a huge flora.

  Liu Taiguo introduced that stripe rust is caused by a germ that only grows on wheat. The germ will die within a few days after leaving the wheat plant.

Liu Taiguo told reporters that in the fungus source bases of Gansu and Sichuan, there is a large altitude difference on the terraces of high mountains, and wheat is also grown in three-dimensional. The germs died early, but a large part of it was transmitted to the confiscated wheat on the mountain along with the updraft; the wheat grains left during the harvesting process under the mountain would sprout to form "self-growing wheat seedlings", and the germs on the mountain would blow down with the wind. Back down the mountain, a large number of "self-growing wheat seedlings" "settled" so that the germs can spend the hot summer and cold winter in the wheat seedlings. Repeatedly, the stripe rust bacteria can complete the "anniversary cycle" in the local area. .

  At the same time, stripe rust has a larger spreading route across the country.

In autumn and winter, some stripe rust bacteria above 2000 meters above sea level will spread southward with air currents such as monsoon, and spread to northern Hubei, southern Henan and other places. The pathogens will fall on the wheat seedlings when the temperature and humidity are appropriate. Will be infected and sick, so that the germs can also survive the winter.

When the southeast wind comes next spring, the spores will be brought back to the northwest again.

  In order to effectively control stripe rust disease, new wheat varieties in the province where the bacteria source is located require high resistance to pass the certification. However, due to the continuous mutation of the pathogen, a highly resistant variety may "lost" disease resistance after a few years, and the pathogen is rapidly increasing. And continue to evolve.

Liu Taiguo introduced that since the founding of the People’s Republic of China, the new race of wheat stripe rust in my country has been updated and iterated many times. The race named "Tiaozhong No. 34" is currently popular. It was first discovered around 2009. It has now spread to all parts of the country.

  The flora is evolving, which means that breeders must continue to improve and cultivate new resistant varieties to cope with the evolution of the flora and achieve the effect of continuous prevention and control.

  Seed industry is the cornerstone of pest resistance

  Variety, pathogen and environment are the three major factors in the occurrence and prevalence of diseases. Liu Taiguo told reporters that this is called the "triangle of diseases" in plant pathology.

Of course, this triangular relationship is more inseparable from the influence of human factors on the occurrence and prevalence of diseases, which is also called the "disease tetrahedron."

  When the human factor joins the war between diseases, pests and crops, the form of this war will inevitably change.

  One of the changes is to investigate and grasp the number of diseases and insects in advance, based on which the scope and extent of the occurrence of diseases and insects can be judged, and then calmly dealt with.

Take wheat stripe rust as an example, including two large-scale surveys of stripe rust bacteria over summer and winter, as well as continuous field monitoring, which play an important role in ensuring the effective prevention and control of wheat stripe rust across the country, and it is in the control of insect pests. For overwintering eggs and larvae, there is the same investigation, which allows growers and agricultural experts to make effective judgments in advance.

  Meteorological conditions are more unpredictable, which is one of the reasons why modern agriculture still has the phenomenon of "relying on the sky for food".

  Fortunately, 2021 is undoubtedly a good year for rice.

  Researcher Hou Maolin, director of the rice pest innovation task of the Institute of Plant Protection of the Chinese Academy of Agricultural Sciences, told reporters that this year the rice pests are relatively light, and the two-migration pests of rice are not too many, "it is God's help."

  Two-migrating rice pests, including rice leaf rollers and rice planthoppers, are more difficult to predict than local overwintering pests.

Hou Maolin explained, "The two-migrating pests of rice mainly migrate from Southeast Asia with the monsoon in the early summer of each year, and the landing is related to the front. However, the specific time and scale of the occurrence of the monsoon and the front are difficult to predict. Therefore, the prediction of the two-migrating pests, It is always difficult to have relatively accurate results."

  At the level of pests, rice in the north, especially rice in the northeast, is not threatened. Hou Maolin explained that this is because most rice pests cannot survive the winter in the north.

In the south, in addition to local overwintering pests, rice also faces two migratory pests such as rice planthoppers and rice leaf rollers.

  For northern rice, if rice blast is well controlled, the possibility of high yield is very high.

Rice blast is one of the most important diseases and insect pests of rice, and it is more harmful. If it is not controlled, it can even directly cause production failure in the event of a major outbreak.

Therefore, rice blast has always been at the forefront in the prevention and control of rice pests and diseases.

Just like the one-vote veto against the high susceptibility of wheat stripe rust in some provinces, rice varieties have the same right of one-vote veto for the resistance to rice blast during the certification of rice varieties.

  Although the damage is serious, there are also very mature prevention and control methods. Kang Houxiang, an associate researcher at the Institute of Plant Protection of the Chinese Academy of Agricultural Sciences, told reporters that in fact, the incidence of rice blast this year is still relatively serious, but because of effective prevention and control, the impact on yield is small. .

  The prevention and control of rice blast benefited from the effects of two aspects. Kang Houxiang explained, “The first is drug control. The current cost of prevention and control is RMB 50-60 for 1 mu of land. The second is resistant varieties. The level of rice breeding in my country is extremely high. Highly resistant varieties are planted in most places. Among them, variety is the most important factor."

  In fact, not only rice, including wheat, corn, and even other crops, in the process of fighting against pests and diseases, highly resistant varieties have always been the most important factor in determining the outcome, and this requires people to make continuous breakthroughs and efforts. On the road of evolution, run ahead of pests and diseases.

  70,000 plant protection drones weave the dense prevention and control skynet

  Researcher Wang Xifeng from the Institute of Plant Protection of the Chinese Academy of Agricultural Sciences introduced that in the decades since the founding of New China, our country has established a complete plant protection system, including those from the Chinese Academy of Agricultural Sciences to the local Academy of Agricultural Sciences. Scientific research forces, from the China Agricultural University to the local agricultural universities, from the national agricultural technology extension center to the plant protection and agricultural technology extension system covering all counties across the country, "research, education, government, mass scientific and technological organizations, and producers are all in In this system, it is very complete and the reaction speed is extremely fast."

  Wang Xifeng told reporters that when he was investigating in the field, he found that there was some kind of virus in the field, so he called a leader of the National Agricultural Technology Extension Service Center. After 15 minutes, the local plant protection station called the phone. It's on his phone.

“We are very sensitive to pests and diseases. As long as we find out, we can implement prevention and control measures in the shortest time,” said Wang Xifeng. “This is precisely the embodiment of our agricultural power and a sign of a complete plant protection system. In fact, this The speed of response is impossible in many small countries with insufficient power."

  In recent years, with the increase in scale and mechanization of agriculture, another force has also joined the plant protection system, that is, the force of agricultural socialized services.

In all parts of the country, especially in the main grain producing areas, a large number of plant protection drones and "pilots" operating drones provide more complete prevention and control services for the growth of food.

  "Compared with human spraying, drones are faster and more effective." Wang Xifeng said.

  Data show that in 2020, the number of agricultural plant protection drones in my country will exceed 70,000. Each drone will spray 300-400 acres of farmland every day, which is 20 to 30 times that of manual spraying.

The service price is not high. According to the reporter's investigation, the service cost per mu of land is 8-15 yuan in different regions.

  From the government to the society, from experts to farmers, a complete and thorough plant protection system has become the most important support for the fight against diseases and insect pests. "Under such a system, the risk of large-scale crop failure caused by diseases and insect pests can be controlled to a minimum. "Kang Houxiang said.

  Pests never sleep, threats are still ahead

  Pests and diseases always accompany the production of food crops, which is the law of nature.

More importantly, in the struggle between humans, crops, and pests and diseases, there have always been near-term worries and long-term concerns.

  For example, invasive pests. In the past few decades, new pests have continuously entered our country, from the American white moth that was introduced to our country in the late 1970s, to the American Liriomyza in the 1990s, and then to 2019. The grass moth...

  "For invasive pests, we have a three-tier control system. First, conduct risk assessments and make early warnings for potential, possible coming, and new invasions. Second, for transboundary pests, such as Spodoptera frugiperda , African locusts, tomato leaf miners, etc., develop rapid detection technologies, establish regional monitoring networks, establish barriers, and kill them in various ways. Third, those that have entered and have occurred in large areas, such as potato beetles, apple ancestral moths, etc., Control the occurrence trend and stop the spread.” Wang Zhenying said, “Our country conducts investigations on the occurrence of various diseases and insect pests every year, forecasts the occurrence trend of diseases and insect pests, and guides the prevention and control. Take Spodoptera frugiperda as an example, in late October this year, the whole country The Agricultural Technology Extension Center organized an investigation on the occurrence of Spodoptera frugiperda in Yunnan Province in winter. When conducting field surveys in Chuxiong and other places, it was found that almost all of the corn plots we surveyed had Spodoptera frugiperda."

  The same is true for the disease. Kang Houxiang told reporters that scientists have found traces of the continuous evolution of the disease in the genes of rice blast, revealing the long history of the fight between the disease and crops and the competition with drugs. This process has never stopped. "In the future, rice blast will still be one of the most important diseases of rice."

  It is worth noting that the rice blast, which originally occurred on rice, is threatening wheat globally. Kang Houxiang told reporters, “The phenomenon of rice blast infecting wheat is called wheat blast. It was first reported in South America in 1984. The outbreak has been spreading for decades, and has now spread to Bangladesh in South Asia, Zambia in Africa and other countries. my country has also established a special monitoring mechanism with professional monitoring equipment to observe its spread speed and path. The best result is to defend against the enemy outside the country, but we must also prepare for the prevention of wheat blast damage, such as stocking disease-resistant varieties."

  The occurrence and damage mechanisms of plant diseases and insect pests are very complicated. Hou Maolin told reporters that many mechanisms have not been fully studied yet, and this has also brought a lot of difficulties to the prevention and control; even some pests and diseases are inextricably linked. For example, rice planthoppers are very harmful to rice, but they also spread rice viruses, causing southern rice black-streak dwarf disease and rice stripe leaf blight.

  Now, 2021 is about to pass, and grain production has reached a new high, and the Chinese people's rice bowl continues to be firmly in the hands of the Chinese.

But it does not mean that the fight against pests and diseases has been won, and the war for food and insects in 2022 will start again.

"This is a protracted battle. As long as humans are still growing food, they will always need to control pests and diseases." Wang Xifeng said.

  Version B06-B07/Beijing News reporter Zhou Huaizong/Photo courtesy of the interviewee