Control of Hoplocampa testudinea using the extract from Quassia amara in organic apple growing

Abstract

In 2008 and 2009 the effects of quassin and neoquassin (oxygenated triterpenes) on apple sawfly (Hoplocampa testudinea Klug, 1814) were studied. In the Czech Republic, monitoring was carried out in small-plot trials and in one laboratory experiment. The extract containing quassin and neoquassin was made by boiling wood chips of a tropical shrub Quassia amara L. (Sapindales: Simaroubaceae). The experimental dosages were 3, 4.5, 6, and 9.25 kg of wood chips/ha. Spray treatment with the quassia extract was carried out just before most larvae hatched out. It was statistically proven that the extract from the wood of Q. amara reduced the apple sawfly infestation of fruitlets. Extract in the dosage corresponding to 3–4.5 kg of quassia wood chips for 1/ha appeared as optimal. The efficacy of these dosages was approximately 40–50%, and the efficacy above 80% was record.