Von
Zimmermann, Olaf; Wührer, B.
Konferenz:
Ecofruit – 14th International Confrerence on Organic Fruit-Growing, Hohenheim, Germany, 22.–24.02.2010
Erschienen in:
Ecofruit: proceedings to the conference from February 22nd to February 24th, 2010 at the University of Hohenheim, Germany (2010), S. 333-336
Egg parasitoids of the genus Trichogramma can be one tool in a strategy against the codling moth Cydia pomonella, e.g. to control late infestation where other control agents cannot be applied. A mechanical application method for parasitized eggs with a better distribution in a spraying cloud could possible improve the efficacy of Trichogramma compared to a single spot release system with cardboard cards. Eggs of Sitotroga cerealella parasitized byTrichogramma evanescens were tested in a liquid formulation with a hydrocolloid. The optimum concentration has been assessed by determination of the viscosity of the formulation: 2-3g/I with xanthan of guar bean flour. Different spraying treatments under semifield conditions resulted in a reduction of the emergence rate between 37 and 69% when the formulation had to pass the spraying tu bes, nozzles and ventilation system. A low reduction between 4-12% could be reached by scattering loose parasitized eggs into the spraying cloud. In practice such an application system would require additional modification to the existing agricultural spraying technique.