"Green" insecticides can be made from tobacco.

Tobacco has been used as a natural pesticide for hundreds of years, but its application has been limited and its use method is very primitive. Commercial production of tobacco-based pesticides may become a new investment hot spot in the future, with tobacco cultivation and pesticide manufacturing likely to benefit from the dual background of widespread criticism of chemical pesticides and growing awareness of the dangers of smoking, a new study said. The study was published in the American Journal of Industry and Chemical Engineering. Cedric Bryans, who led the study, and colleagues point out that many tobacco farmers are suffering from concerns about health problems caused by smoking and increasingly stringent smoking bans in various countries. So scientists are looking for other uses for tobacco. Making natural pesticides from tobacco is undoubtedly the most promising of the existing schemes, since gardeners mixed shredded tobacco leaves with water to kill insects a century ago. This "green" pesticide is produced from tobacco leaves, which can bring extra income to tobacco farmers and is also very environmentally friendly. Researchers say it is now possible to produce tobacco pesticides by pyrolysis. In a high-temperature vacuum device, tobacco leaves are heated to 482 degrees Celsius, producing a substance called "bio-oil." Experiments have shown that the bio-oil produced by tobacco leaves kills a wide range of pests, including 11 species of fungi, colorado beetles and currently common pests resistant to chemical pesticides. In experiments, the oil killed all beetles and inhibited the growth of two bacteria and one fungus. Even if nicotine is removed from it, bio-oil is still effective at killing pests. The ability to inhibit some, but not all, microbes makes it a new type of selective insecticide, researchers believe.