As more and more chemical pesticides are being banned in Switzerland, farmers are looking for natural alternatives to conventional pesticides. You can deal with a carrot fly with onions. The portal tells www.lid.ch.
The carrot fly causes damage to crops, as its larvae gnaw holes in carrot roots.
E. Hermann AG, located in Sarganserland, Switzerland, specializes in vegetable production and grows carrots on 35 hectares of its own and leased land. Farm manager Benno Herler has been relying on onion oil for two years now to use chemical plant protection products as infrequently as possible: it serves as a natural repellant against carrot flies. The farmer learned about this method by reading about research done on organic farms in the Netherlands. The onion oil dispensers and capsules were supplied by Andermatt Biocontrol. 4-6 dispensers with capsules are distributed per hectare. The capsules are protected from the rain, and the onion smell spreads across the field from the slits on the side.
It is important that the field give off an onion scent when the flies arrive from the edges of the field in the late afternoon. “The flies really seem to be drifting off course and are less active in laying their eggs in the ground. Obviously, a lot also depends on the weather. Since the carrot fly does not lay its eggs on the plant, but in the ground, in a dry year, many eggs die. Wet years favor egg development,” Herler concludes from his observations.