Control of Rhizoctonia Stem Rot of Poinsettia During Propagation with Fungicides that Prevent Colonization of Rooting Cubes byRhizoctonia solani

The effectiveness of several fungicides applied either as foliar sprays or as rooting-cube soaks was compared for control of Rhizoctonia stem rot of poinsettia during propagation. Rhizoctonia solani was introduced to the surface of rigid foam rooting cubes at the time cuttings were stuck. Benomyl at 0.3 g a.i./L, chlorothalonil at 1.8 ml a.i./L, flutolanil at 0.3 g a.i./L, iprodione at 0.6 g a.i./L, and metalaxyl + benomyl at 0.5 g a.i./L all prevented stem rot. Rooting-cube soaks of flutolanil, iprodione, and metalaxyl + benomyl were as effective as foliar sprays in disease control. Foliar sprays of quintozene at 0.45 g a.i./L and ethazole + thiophanate methyl at 0.24 g a.i./L were not as effective in control of stem rot as the other fungicides tested (.)