Use of Guazatine and Flutriafol for the Control of Take-All and Rhizoctonia Root Rot of Wheat.

Abstract

A series of experiments with artificially inoculated soil was undertaken to test the efficacy of the fungicide guazatine against take-all and Rhizoctonia root rot of wheat (caused by Gaeumannomyces graminis var. tritici and Rhizoctonia solani, respectively) and to develop a chemical control technique against Rhizoctonia root rot. Guazatine was ineffective as a soil-applied fungicide against both diseases but, as a seed dressing in combination with soil-applied flutriafol, it reduced incidence and severity of Rhizoctonia root rot at 4 weeks though not that of take-all. In the glasshouse, flutriafol-amended double superphosphate at rates equivalent to 100 g and 200 g a.i./ha |+- guazatine seed dressing (0.5 g a.i./kg seed) reduced Rhizoctonia root rot and improved plant growth at 8 weeks. In small field plots, flutriafol-amended fertiliser at 200 g a.i/ha reduced Rhizoctonia root rot severity. Flutriafol-amended fertiliser therefore shows potential for the control of Rhizoctonia root rot of wheat at relatively low concentrations.