Browsing by Author "Demirci, Fikret"

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Effects of Some Fungicides on Isaria Farinosa, and in Vitro Growth and Infection Rate on Planococcus Citri
(Springer, 2011) Demirci, Fikret; Mustu, Murat; Kaydan, M. Bora; Ulgenturk, Selma
The effects of some fungicides used against citrus diseases, on mycelial growth and conidial germination of Isaria farinosa (Holmsk.) Fries [Sordariomycetes: Hypocreales] and also on the pathogenicity of the fungus on citrus mealybug, Planococcus citri (Risso), were determined. Systemic fungicides such as tebuconazole, penconazole and nuarimol were the most effective as regards both conidial germination and mycelial growth. Protective fungicides such as captan, chlorothalonil, mancozeb and propineb inhibited conidial germination at between 1 and 5 mu g ml(-1) concentration, but captan, chlorothalonil and propineb did not inhibit the mycelial growth at 5,000 mu g ml(-1). Mancozeb inhibited mycelial growth between 2,500 and 5,000 mu g ml(-1). Sulphur and copper oxychloride did not inhibit the fungus even at very high concentrations. Sulphur, copper oxychloride, fosetyl-al, chlorothalonil and carbendazim did not decrease the mortality percentage caused by I. farinosa. Tebuconazole, penconazole and mancozeb were the most effective and respectively reduced the mortality from 83% to 33%, 28% and 30% in the ovisacs, from 81% to 29%, 27% and 29% in the 1st instar larvae, and from 84% to 34% in the adult females.
Laboratory Evaluation of the Effectiveness of the Entomopathogen; Isaria Farinosa, on Citrus Mealybug, Planococcus Citri
(Springer Heidelberg, 2011) Demirci, Fikret; Mustu, Murat; Kaydan, M. Bora; Ulgenturk, Selma
Citrus mealybug Planococcus citri (Risso) (Hemiptera: Pseudococcidae) is one of the main pests on citrus trees. Biological control of the pest is based on the release of hymenopterous parasitoids and coccinellid predators at present. The effectiveness of entomopathogen fungus Isaria farinosa (Holmsk.) Fries ([Sordariomycetes: Hypocreales] (Syn: Paecilomyces farinosus), as an alternative biological control agent on citrus mealybug, was investigated using four different inoculum densities and different relative humidities (RH). The entomopathogen caused 89.39% mortality in ovisacs, 84.07% mortality in second larval stage, 84.53% mortality in adult females, and 78.71% mortality in first larval stage at 95% RH and at 1 x 10(8) conidia ml(-1) inoculum concentration. Percent mortalities were between 50 and 60 in ovisac, first and second larval stage at 95% RH and at 1 x 10(7) conidia ml(-1). Percent mortality was decreased parallel to the decrease in humidity level and inoculum densities; however, the fungus caused significant infection in 70% and 80% RH. These results demonstrated that the effectiveness of the entomopathogen is promising for biocontrol of citrus mealybug.
Paecilomyces Lilacinus, a Potential Biocontrol Agent on Apple Rust Mite Aculus, Schlechtendali and Interactions With Some Fungicides in Vitro
(Springer, 2010) Demirci, Fikret; Denizhan, Evsel
The apple rust mite Aculus schlechtendali (Nal.) (Acari: Eriophyidae), is a main pest in apple-growing areas in Ankara, Turkey, and chemical control applications have some limitations. Entomopathogenic fungi have a potential for biological control of mites. In this study, an entomopathogenic fungus, Paecilomyces lilacinus (Thom) Samson (Deuteromycota: Hyphomycetes), was first isolated from the mite cadavers on Japanese crab apple leaves and pathogenicity of the fungus was observed in different inoculum densities and relative humidities. The pathogen caused up to 98.22% mortality of the mite population. The effects of some fungicides on the entomopathogenic fungus were determined in in vitro studies. Carbendazim, penconazole and tebuconazole were the most effective fungicides on mycelial growth of P. lilacinus, with EC50 values under 3 A mu g ml(-1). In spore germination tests, captan, mancozeb, propineb were the most effective fungicides, followed by tebuconazole, penconazole, nuarimol and chlorothalonil. Sulphur could not inhibit the conidia germination totally at 5,000 A mu g ml(-1). Copper oxychloride and fosetyl-al prevented conidia formation at concentrations above 1,000 A mu g ml(-1).