Evaluation of the occurrence of bean plants (Phaseolus vulgaris L.) affected by bean seed fly, Delia platura (Meigen), grown under different sowing techniques and with different forms of pesticide application

The bean seed fly, Delia platura, attacks the seed or the cotyledons of bean seedlings before sprouting. The larvae penetrate the germinating seeds or the seedlings and mine the cotyledons, the small shoots and/or young roots, before sprouting, causing widespread damage. This work was carried out during 1998 and 1999 in the province of Leon, Spain, using replicated split-split-plots in which the primary, secondary and tertiary factors were, respectively, bean landrace, pesticide application system and sowing technique. Highly significant differences were noticed as regards application of pesticides, which reduced damage significantly compared with controls. As regards sowing techniques, significant or highly significant differences were noticed in the 1999 plots only, where the number of plants damaged was lower on the flat with substrate added to the sowing line. A significant or highly significant interaction between pesticide application and sowing technique was found in all the plots except one. (C) 2003 Elsevier B.V. All rights reserved.