In the late 1920s, in China, agriculture was destroyed and disasters occurred everywhere, and scale insects were blown up in Jiangsu, Zhejiang, Fujian and other places, seriously endangering citrus. Being in a hurry and not afraid of hardships, Ren Jiguo decided to collect and introduce Korean pine in Taiwan Province Province, which was occupied by the Japanese at that time. He arrived in Taipei by Japanese ship, and with the help of Japanese entomologist Sumuyoshi, he collected a large number of scarlet ladybugs. After returning, he personally released the scale insects in citrus orchards which were seriously affected along the way, and successfully controlled the harm of some citrus orchards.
In China, turpentine mixture was first used to control scale insects.
In the early 1930s, serious scale insects occurred in many citrus orchards in Zhejiang Province. Although a batch of scarlet ladybugs were introduced from Taiwan Province Province in 1929 and released into citrus orchards, the natural reproduction and diffusion of scarlet ladybugs are difficult to control the large-scale occurrence of scale insects. Ren is actively looking for ways to prevent and control drugs. At that time, the better drug to control this insect was turpentine mixture. It was first used in Japan, and it was made by boiling excessive sodium hydroxide (caustic soda) solution, adding rosin and heating to saponify rosin. At that time, caustic soda was difficult to obtain and operate in rural areas of China. In view of this, sodium carbonate (alkali powder) was used instead of caustic soda to prepare turpentine mixture, and the results showed that the control effect on scale insects was very good (insect and plant diseases, 1933). The preparation also reduces the corrosiveness of caustic soda to citrus. Ren is the first person to develop turpentine mixture in China, and he has achieved success in controlling citrus scale insects.
Research and development of insecticidal plants
Contribute to the development of China's derris production. In the mid-1930s, Ren began to collect insecticidal plants from China. 1937 During her master's degree at the University of Minnesota, USA, systematic experiments were carried out on six kinds of insecticidal plants, including China Derris. The experiment was carried out with the extracts of ether, phenol and benzene (5 concentrations). The results showed that the contact toxicity of various insecticidal plants was clear, among which rattan was the most effective, followed by rattan and croton.
Thirdly, tripterygium wilfordii has little effect, and bitter bark and rhododendron are ineffective, which has important reference value for the further research and utilization of insecticidal plants in China.
From 65438 to 0952, according to the spirit of developing domestic insecticidal plants by the Ministry of Agriculture, Ren went to southern China to investigate the resources of Derris, and basically found out the species, distribution, cultivation and growth of wild species of Derris in southern provinces (Guangdong, Guangxi, Yunnan, etc.). ), and the relationship between the growth of derris and climate, soil and other conditions; It is clear that areas with annual average temperature of 20-22℃ and rainfall of 1 500mm are suitable for planting, that is, China, Guangdong, Guangxi, Yunnan and other provinces, and areas south of 23 north latitude can be planted.
According to the investigation, there are 6 species and varieties of Derris pubescens. South China Sarah Clark Gripin: (1); (2) Porphyridium ellipticum; (3) Malaquin-Jinta type; ; (4) Chaetomium sp. Salava Kensis; (5) Tung oil tree; (6) Poisonous derris or derris. The investigation also clarified the content of rotenone in various plants of Derris. Ren's investigation has contributed to the development of the insecticidal plant Derris in China.
Organize and plan the advent of organic pesticide bhc.
In the early 1950s, it was the beginning of the founding of People's Republic of China (PRC) when he served as the director of the Medical Devices Division in the Central Ministry of Agriculture. At that time, only a few domestic manufacturers could produce a few inorganic pesticides and plant pesticides such as lead arsenate, copper sulfate, copper sulfate and derris, and there was no factory to produce organic synthetic pesticides. At this time, a large number of bhc and DDT were produced abroad. Ren suggested that the state organize the production of bhc and Heineken. After being approved, he immediately went to all parts of China to organize planning. More than a year later, he finally produced BHC and Heineken for the first time in China, which ended the history that China could not produce organic synthetic pesticides and laid the foundation for the further development of pesticide industry in China.
Presided over the Department of Plant Protection of Shenyang Agricultural College.
Contribute to the cultivation of sericulture talents in plant protection 1954 The Department of Plant Protection of Shenyang Agricultural College lacks teachers in entomology and pesticide science, but has expertise in both fields, so Zhang Kewei, dean of the college, invited him to be a professor and head of the Department of Plant Protection of Shenyang Agricultural College. At that time, Shenyang Agricultural College was just established, with heavy tasks. He organized all the teachers in the department and worked out new teaching plans and syllabuses for more than 10 courses, so that the whole department had laws to follow in teaching. Thanks to Ren's efforts, he led all faculty members to be loyal to the Party's education, worked hard to train teachers, actively expanded the laboratory, acquired instruments and equipment, and organized teachers and students to collect specimens extensively. After two years' efforts, the Department of Plant Protection has made great progress, and the level of teachers has improved rapidly. The laboratory has been able to meet the teaching needs. This creates conditions for improving the quality of teaching.
Liaoning Province is rich in tussah resources, and the output of tussah silk ranks first in China. In order to develop sericulture, Shenyang Agricultural College added sericulture specialty. The plant protection department undertook this task. Ren actively organized some teachers to prepare for the construction. From 65438 to 0958, the first sericulture major in China was born in the Department of Plant Protection of Shenyang Agricultural College, and 30 freshmen of the first sericulture major also entered the school in September of the same year. Wang Daorong, He Kang, etc. Have applied for the position of professor of sericulture. By 1966, Shenyang Agricultural College has trained more than 700 undergraduate graduates majoring in plant protection and sericulture. He has been teaching in Shenyang Agricultural College for nearly 30 years (1954-1983). He worked hard and made great contributions.
The corn borer was studied and observed for more than 30 years, and the viewpoint of radical cure was put forward.
From 65438 to 0954, Ren came to Shenyang Agricultural College and began to study the prevention and control of corn borer. At the beginning, chemical control experiments were carried out. In view of the continuous planting of corn in China, especially in the Songliao Plain of Northeast China, it is difficult to control corn borer in a large area by artificial application of pesticides, so he designed and implemented the ground chemical control experiment aimed at aircraft control (which was the first in China at that time). The results showed that (1) when adding 0.5% bhc, the hatching rate of eggs reached more than 50% after the peak, (2) the effects of liquid and powder were basically the same; (3) The effect of1time is not much different from that of 2 times, and one application is the most economical.
Ren also investigated the occurrence law, prediction method and host plants of corn borer. Under his leadership, it is the first time to report the mutant corn borer that harms non-gramineous hosts (such as hemp and xanthium sibiricum).
These studies have played a guiding role in the research and control of corn borer in Liaoning Province and northern provinces (regions). Although the large-scale control of corn borer was not realized by spraying drugs by plane before his death, it laid the foundation for his later work.
Ren has observed, studied and explored corn borer for many years, and constantly collected and sorted out a large number of research materials at home and abroad. He believes that the best way to control corn borer is insect-resistant breeding, and collects insect-resistant test data and related documents everywhere. He has attracted a large number of foreign maize inbred lines and insect-resistant varieties from Qiu Shibang, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, and conducted comparative observation and experiments for two years. Some of them have shown promising signs, but unfortunately, all these precious raw materials were destroyed in the "Cultural Revolution". At the end of 1970s, when he was nearly eighty years old, he was sickly, unable to do anything, and his assistant was transferred, so he could no longer engage in field experiments. However, he kept consulting domestic and foreign literature and wrote articles such as "Discussion on the Periodic Occurrence Law of Corn Borer" for future generations.
Love the motherland, love science, teach and educate people, and be a teacher.
Ren has infinite love for the people of China, the motherland and the people. He worked hard all his life and never cared about personal gains or losses. In addition to teaching and scientific research, he also has a lot of tedious teaching administrative work and social activities, leading the two-level Plant Protection Society in Liaoning Province and Shenyang and the Shenyang Insect Society. Regularly organize academic activities and production inspections, and put forward production suggestions to all parties. Ren is an old member of the Jiu San Society. He actively participated in the activities of Jiu San Society and CPPCC, and often put forward valuable opinions. Ren not only made important contributions to teaching, scientific research, production, study and learning activities, but also played an active role in uniting the vast number of scientific and technological personnel.
As long as he is honest, comrades of all ages can live in harmony with him. He can unite the old teachers in the department and do great things in the business department. He loves young teachers and cares about their growth and progress, and is respected by all teachers and students.
Ren loves students and often educates them to love science and specialty. Under his education and infection, many students study hard, hard and hard. He is worthy of being a good teacher for students and a mentor for teachers.
Ren is one of the founders of the Chinese entomological society and served as the first and second director. He is also the editorial board member of Journal of Entomology and Journal of Plant Protection, the chairman and honorary chairman of Liaoning and Shenyang Plant Protection Societies, and the chairman of Shenyang Insect Society. The first, second, third, fourth, fifth, sixth and seventh directors of Shenyang CPPCC, the fifth, sixth and seventh vice-chairmen of Shenyang CPPCC, and a member of Shenyang Branch of Jiu San Society.