Sensitivity of Botrytis cinerea from vegetable greenhouses to boscalid

Abstract

Between 2004 and 2006, 228 isolates of Botrytis cinerea from two regions in China were characterized for baseline sensitivity to boscalid, a new active ingredient that interferes with succinate ubiquinone reductase in the electron transport chain. The isolates showed similar sensitivity in different years and regions. Baseline sensitivities were distributed as unimodal curves with mean EC 50 values of 1·07 ( ± 0·11) and 0·42 ( ± 0·05) mg L − 1 for inhibition of mycelial growth and conidial germination, respectively. Laboratory studies were conducted to evaluate the risk of development of resistance to boscalid. Boscalid-resistant mutants were obtained by UV-treatment at lower frequencies and with smaller resistance factors than pyrimethanil-resistant mutants. All boscalid-resistant mutants were also significantly more sensitive to Qo inhibitors than their wild-type parents and showed reduced sporulation in vitro and pathogenicity on aubergine leaves. The results suggested that the risk of resistance developing for boscalid was lower than for pyrimethanil. However, as B. cinerea is a high-risk pathogen, appropriate precautions against resistance development should be taken. Synergism between the activity of boscalid and that of kresoxim-methyl was observed.

Effectiveness of isofetamid, a new succinate dehydrogenase inhibitor fungicide, in the control of grapevine gray mold

“…However, for isolates with a previous history of SDHI fungicide exposure, conidia were less sensitive than mycelium. These findings are in contrast with previous reports that mycelium and conidia are equally sensitive (Myresiotis et al, 2008) or that mycelium is less sensitive than conidia (Zhang et al, 2007) to boscalid, a fungicide with the same mode of action as isofetamid. Although B. cinerea isolates were not previously exposed to isofetamid, the in vitro EC 50 for mycelium and conidia varied substantially between the isolates.…”

Detection and characterization of benzimidazole resistance of Botrytis cinerea in greenhouse vegetables

“…Technical grade diethofencarb and benzimidazole fungicides, including carbendazim and thiophanate-methyl, were dissolved in acetone except that carbendazim was dissolved in 0.1 mol l −1 hydrochloric acid (HCl) to prepare the stock solutions (Zhang et al 2007). …”

“…l −1 of medium (Yarden and Katan 1993;Leroux et al 2002) according to the method described previously (Zhang et al 2007). For each isolate, the average colony diameters measured in two perpendicular directions was used to calculate the EC 50 (the fungicide concentration that results in 50% radial growth inhibition) by linear regression of probit % inhibition of radial growth as a function of the log 10 fungicide concentration.…”

“…From 2003 to 2006, a total of 426 single-conidial isolates were collected as described previously (Zhang et al 2007) from 32 commercial greenhouses of vegetable crops (strawberry, tomato, eggplant and pepper) located in Zhejiang and Jiangsu provinces, which are the major vegetable production regions in China (Table 1). Five to ten isolates were collected from each greenhouse.…”

Residue analysis of kresoxim‐methyl and boscalid in fruits, vegetables and soil using liquid–liquid extraction and gas chromatography–mass spectrometry

“…Both are broadspectrum fungicides that are used to control a wide range of diseases in fruit and vegetables (Karaoglanidis and Karadimos, 2006;Jobin and Carisse, 2007;Zhang et al, 2007;Smith et al, 2008). In order to optimize the bactericidal eff ects, a mixed formulation of kresoxim-methyl and boscalid was developed by BASF Co. Ltd., which showed good effi cacy in controlling strawberry grey mould disease (Zhang et al, 2008).…”