Entomopathogenic nematodes were tested for their potential as tool in resistance
management of codling moth Cydia pomonella L. in organic fruit growing. In two field tests,
the adults emerging from stems treated with nematodes were monitored. In one trial, 90 %
of efficacy could be shown. On-farm trials with favourable weather conditions showed an
efficacy about 50-60 % on fruit infestation by codling moth in the year following the
application. On-farm trials with unfavourable weather conditions showed no results. The
favourable weather conditions for the application are discussed with reference to German
conditions