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A total of 19 pesticide preparations were used according to agricultural practice in six trials in apple orchards. Using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS), premature Golden Delicious apples collected 64, 50, 36 days before harvest and mature fruit were examined for residues of active ingredients. No residues of triflumuron, triazamate, chlorpyrifos, etofenprox, fenoxycarb, kresoxim-methyl, cyprodinyl, difenoconazole or thiram were detected in the first sampling. Also, the levels of chlorpyrifos-methyl, penconazole, tebuconazole and tolylfluanid dropped during the pre-harvest interval. Detectable residues of pyridaben, thiacloprid, trifloxystrobin and tetraconazole in harvested fruits were below 0.01 mg kg(-1), which is the maximum concentration of residues acceptable by baby-food producers in any raw material. The only residues exceeding this concentration were captan and teflubenzuron. Based on the data, farmers can choose pesticides for optimal treatment of plants, while enabling growth of a safe crop suitable for baby-food production.

Zichová T., Falta V., Kocourek F., Stará J., 2011. Diff erences in the susceptibility of codling moth populations to Cydia pomonella granulovirus in the Czech Republic. Hort. Sci. (Prague), 38: 21-26.Th e Cydia pomonella granulovirus is a very important agent for the biological control of the codling moth, Cydia pomonella, in both organic and integrated apple and pear production. Th ree populations of Cydia pomonella originating from three separate areas of the Czech Republic were tested for their susceptibility to Cydia pomonella granulovirus in laboratory bioassays at several concentrations of Cydia pomonella granulovirus. A sensitive laboratory strain was chosen as a control. Th e larval mortality was checked 14 days after the infection. Th e mortality of Cydia pomonella larvae was similar in specimens originating from both the wild populations and the laboratory strain. Decreased susceptibility to Cydia pomonella granulovirus was demonstrated neither in samples from locality without Cydia pomonella granulovirus treatment nor from a locality experimentally treated with Cydia pomonella granulovirus for several years during the registration process. However, one population experimentally treated for more than 10 years was partially resistant to Cydia pomonella granulovirus. Based on our fi ndings; the Cydia pomonella granulovirus biopesticides will be effi cient due to the high susceptibility of fi eld codling moth populations to Cydia pomonella granulovirus in the Czech Republic.

Psota V., Ouředníčková J., Falta V., 2010. Control of Hoplocampa testudinea using the extract from Quassia amara in organic apple growing. Hort. Sci. (Prague), 37: 139-144.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.

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