Bactrocera oleae (Gmelin) control in organic olive farming.

Summary

In the Mediterranean area the olive fly control, difficult to realise in conventional farming, becomes even more arduous in organic farming, owing to the restrictions laid down by Regulation. The EC Reg. 2092/91 which implements organic farming and its updates provide standards allowing only the use of natural origin substances for crop protection contained in annex IIB, forbidding the chemical pesticides use. The present study has been performed in Calabria (Southern Italy) in two different pedoclimatic olive areas (Mirto-Crosia and Terranova da Sibari) and in two observation years (2005-2006) in order to assess the efficacy of substances listed in the annex IIB as copper (antibacterial substance) and biopesticides azadiracthin and rotenone and the efficacy of kaolin and the antibacterial substance propolis. These substances were compared among them and with theses used as control (treated only with water) and in Mirto-Crosia field with conventional product dimethoate. The present research confirms the need to restrain the Bactrocera oleae (Gmelin) infestation in olive areas of the Southern Italy. The results obtained in the two different investigated areas in both years indicated that kaolin has great potential for the control of B. oleae infestation. The use of copper and propolis showed a good efficacy both on adult and preimago population. Rotenone application confirms its known efficacy in Terranova da Sibari area while it does not appear very efficacious in Mirto-Crosia area. Azadiracthin turned out to be not so efficacious for olive fly control in both olive areas and years. On the basis of the results of the most recent studies, a revision of the Regulation is needed.