In order to kill mites, she became friends with bacteria carrying insects
Patriotic striver
Picking up a bottle and gently opening the lid, a group of small predatory mites immediately crawled out. Zhang yanxuan, a researcher at the Institute of plant protection, Fujian Academy of Agricultural Sciences, carefully placed these "little guys" on the tea while patiently guiding tea agronomy technology.
Not long ago, Zhang yanxuan just won the 2018 Fujian Provincial Science and Technology Award "major contribution award in science and technology". Without caring to share the joy of winning the prize with the people around her, she threw herself into her work nonstop. "Winning the prize only shows the past. I have a lot to do in the future." She said to the reporter of science and technology daily with a smile.
Over the past 35 years, Zhang yanxuan has devoted herself to the basic research of agricultural mites and the research and development of mite hunting related products, and has made outstanding contributions to promoting the biological control of crops and the industrialization of crops in China.
Determined to change farmers' production difficulties
In 1975, young Zhang yanxuan was sent to the rural areas of Fuzhou to jump the queue and live a peasant life of working at sunrise and resting at sunset. "The four years of educated youth not only made me feel the simplicity and kindness of farmers, but also made me feel the bitterness of insects that made farmers lose their hard work." recalling the scenes when crops that were hard planted were destroyed by pests, Zhang yanxuan has been distressed, "since then, I want to be an expert in agriculture to 'subdue' pests".
Zhang yanxuan, who wanted to change the plight of farmers' production, was admitted to the Department of agronomy of an agricultural college in Fujian Province after resuming the college entrance examination. Later, due to her excellent academic performance and outstanding scientific research achievements, she was exceptionally admitted as a doctoral candidate by Hokkaido University in Japan, and received a full scholarship. Since then, she has embarked on the road of "fighting" with mite pests.
Mite pests are small in size, but they have strong stress resistance, fast reproduction speed and great difficulty in research. China is one of the countries most seriously affected by mites in the world, and about 40% of pesticides are used to control mites every year. Zhang yanxuan told reporters that among them, tea, cotton, citrus, apples and other crops need to be treated with chemical pesticides 4 to 15 times a year. Because chemical pesticides only act on the surface of crop leaves, long-term use will penetrate the land, causing serious environmental pollution and affecting the growth of crops.
However, for a long time, due to the lack of scientific planting technology and knowledge, farmers mainly use traditional pesticide pest resistance methods, and have not explored other effective ways.
"Every time I go to the countryside and see farmers spraying pesticides on orchards and farmland again and again in the hot sun, I feel bad. Doing so can only cure the symptoms, not the root cause, and will also pollute the land. Therefore, I am determined to develop a good technology that can increase production and income with less pesticides!" Zhang yanxuan said.
So how to fight against "stubborn" mites? Zhang yanxuan turned her eyes to their natural enemy, predatory mites. "If harmful mites are rats, predatory mites are cats. They have the ability to actively track and hunt harmful mites. They can sweep away harmful mites hidden in tree seams, leaf buds and stems, and adopt biological control methods to achieve the effect of 'treating mites with mites'." Zhang yanxuan said.
Since one of the "family members" of predatory mites, Cucumis Ambrosius, was introduced from Britain in 1997, these "little things" have become Zhang yanxuan's intimate "partners".
Under her careful "upbringing", these predatory mites neither bite people, nor eat crops, but also prey on harmful mites such as red spider, which provides a good variety of natural enemies for the effective control of harmful mites in China.
Help industrialized mass production of predatory mites
Recalling the days when she first "raised" predatory mites, Zhang yanxuan is still filled with emotion. "Although predatory mites have achieved remarkable results in eliminating harmful mites, they are also very difficult to domesticate. There are less than 20 predatory mite varieties that can achieve large-scale production in the world. At that time, the industrialized production technology of predatory mites in China has not been broken through. Farmers can only use traditional methods without this low-cost and high-yield technology." She said.
The traditional method of breeding predatory mites is to reproduce predatory mites by using pollen or planting crops. This method is not only costly and time-consuming, but also a problem in storing and transporting predatory mites because pollen and plant leaves are perishable. In the face of such a situation, Zhang yanxuan was burning with anxiety, "but it's no use just worrying. I have to find a way to solve the problem. I have limited power alone, so go out and ask for help".
Therefore, since 1998, Zhang yanxuan began a 20-year quest.
In the spring and autumn of 20 years, she visited more than 20 provinces and 500 counties and cities in China. After thousands of investigations and experiments, she successfully domesticated the muskmelon mite, which can grow in farmland and orchards and can prey on mites, and solved the technical problems of product packaging, refrigeration and transportation.
The successive advent of these breeding and storage technologies has solved the bottleneck problem in the application of China's "mite control" technology, by which China has finally realized the industrialized production of predatory mites, ending the history of being unable to produce predatory mites.
Developing technology is only the first step, and there are more difficult tasks waiting for Zhang yanxuan. In practical application, Zhang yanxuan found that the new species of predatory mites she developed can only destroy harmful mites such as red spider and rust tick, but can do nothing about other pests. This makes some farmers have to use pesticides again, which weakens the effect of biological control.
In order to break through this bottleneck, in 2012, Zhang yanxuan proposed the solution of "killing two birds with one stone": let artificially produced predatory mites carry entomogenous fungi. When they wander around to prey on harmful mites, they can infect and kill other pests.
Always stick to the investigation of going up the mountain on crutches
"Application is the end result of agricultural scientific research and technological research and development." The close integration of scientific research and production has always been the purpose of Zhang yanxuan's work.
"We work at the grass-roots level, and we can directly receive feedback on the effect of technology application. Farmers' brothers look at the results of technology use. If we can't solve the problem, even if the experts exaggerate, the masses still don't buy it." Zhang yanxuan lamented that at the beginning, she adopted the traditional "nanny" promotion method to give predatory mites to farmers, but farmers either asked for subsidies or simply threw away the products, which made her "once very stimulated".
Due to the impasse of the old road, Zhang yanxuan decided to explore a new method, that is, to promote technology through market-oriented operation. In 2005, she raised funds by herself and taught herself about company management. With the strong support of the Fujian Academy of Agricultural Sciences, she set up her own company and set up a risk compensation mechanism to promote the marketization of the "mite control" technology. "At that time, I promised the farmers that if the technology used failed, we would pay compensation.
At the same time, we also provide free comprehensive prevention and control technology consulting and supporting services to farmers. " She said.
Through market-oriented operation, this technology not only "takes root and sprouts" in southern fruit trees, but also "blooms and bears fruit" in Northwest cotton fields. From February, 2008, the predatory mites "cultivated" by Zhang yanxuan began to go abroad and exported to the Netherlands, Germany and other countries. At the same time, Zhang yanxuan continued to reduce production costs from a technical point of view, and built the country's first standardized and industrialized production base of predatory mites with an annual output of 800billion.
Over the past 35 years, Zhang yanxuan has sat on a tractor, lived in a cowshed and stables, and once accidentally broke her femur from a rock after the rain, which has become a persistent disease that plagues her for years in the future.
For more than ten years, in order to stop the femoral pain when going to the field, she had to live on "fenbide". But even so, she still sticks to the investigation on crutches all year round, and guides more than 50000 farmers to learn technology hand in hand. Zhang yanxuan said with a smile that all the efforts were worth it.
From 1998 to 2018, the "mite control" biotechnology was promoted for 40.07 million mu times in citrus, cotton, chestnut, tea, vegetables, apples and other production areas in 32 provinces of China,
Increase the selling price of agricultural products in the above-mentioned production areas by 5% to 15%, reduce the annual use of pesticides by 40% to 60%, train 84300 farmers, and the relevant technical team cooperates with CCTV to shoot 6 scientific and educational films.
Today, Zhang yanxuan, who is approaching retirement, is still busy every day, but she enjoys it. "I am very lucky to be able to meet the needs of the country and contribute my modest efforts. In the future, I will continue to work hard to make thousands of people eat food without pesticide residues and develop new technologies to reduce the environmental pollution caused by pesticides." She said.