Compatibility of Coniothyrium minitans with compound fertilizer in suppression of Sclerotinia sclerotiorum

Abstract

Coniothyrium minitans is a mycoparasite and a promising biocontrol agent of Sclerotinia sclerotiorum, the causal of Sclerotinia stem rot of oilseed rape. In order to assess whether soil application of C. minitans can be combined with fertilizer application during cultivation of oilseed rape, a study was conducted to determine the compatibility of C. minitans with commercial N–P–K compound fertilizer. Results showed that the compound fertilizer at concentrations of 0.1–10% inhibited conidial germination and mycelia growth of C. minitans in a dosage–response manner in vitro. Simultaneous application of C. minitans and the compound fertilizer at various concentrations significantly (P<0.05) reduced the number of apothecia produced by sclerotia of S. sclerotiorum in both pot and field plot experiments. No negative effects of the compound fertilizer on the ability of C. minitans to infect sclerotia of S. sclerotiorumin vitro or to suppress carpogenic germination of sclerotia of S. sclerotiorum were observed. It is demonstrated that C. minitans is compatible with the compound fertilizer when applied at planting of oilseed rape. Application of C. minitans together with the compound fertilizer would be advantageous in saving labor cost, thus increasing production efficiency of oilseed rape.