Using physical barriers to prevent carrot fly (Psila rosae (Fabricius)) damage in domestic production

A field experiment was used to assess the effectiveness of different barriers in protecting garden‐scale carrot production from carrot fly (Psila rosae (Fabricius)) damage. Some of the vertical barriers tested were found to provide a useful method of protecting early season carrots from carrot fly in terms of the percentage of carrots free from damage but, under cumulative pest pressure of several generations of carrot fly, such barriers were found to provide insufficient protection. Gardeners should therefore completely cover their carrot crop to attain an acceptable level of control, and this was found to be especially important for carrots harvested later in the season. There were positive effects of some barrier types on yield which may be due, at least in part, to the protection given by the barriers to carrot seedlings.