Looking back
For well over 2000 years, farmers have found it necessary to use chemicals to protect their food crops.
Democritos of Abdera (460 – 380 BC) recommended soaking seeds in Sedum juice to protect them against disease before sowing. The Roman Plinius the Elder (79 – 23 BC) reported on the use of ashes, crushed Cyprus leaves and diluted urine as crop protection products.
So serious were the threats from pests and diseases that Papal edicts were issued against them and legal action was even undertaken! For example, in 1476 in Berne, Switzerland cutworms were taken to court, pronounced guilty, excommunicated by the Archbishop and then banished. In 1485 the High Vicar of Valence commanded caterpillars to appear before him. Despite their defence council, he eventually condemned them to leave the area.
Revolution and blight
Europe’s agricultural revolution (1750-1880) resulted in more extensive international trade. It also promoted crop protection and use of the botanical insecticides pyrethrum and derris.
Potato blight hit Europe in two waves in the 19th century. In 1845 and 1846, the destruction of the entire Irish potato crop by the blight fungus had far-reaching effects. 1.5 million people starved to death and 2.5 million were forced to emigrate to America. Almost 700,000 people died in Germany during the ‘turnip winter’ of 1917-18 when they were forced to survive on turnips, again after loss of the potato crop. Blight is now kept in check by modern fungicides.
In the 1880s, farmers turned to a wide range of organic and inorganic chemicals such as nicotine, copper solutions, arsenic, cyanide, sulphur powder and caustic lime to control pests. Many of these chemicals are highly toxic and so were very hazardous for those who used them. The first books and papers devoted entirely to pest control began to appear at this time, covering cultural, biological, varietal, physical and chemical control. Chemists subsequently began to synthesise more reliable treatments, the forerunners of today’s highly researched products.
