By using the test fungus Macrophomina phaseolina, residues of triadimefon were found in straw collected after harvest from sprayed plants of wheat varieties Kharchia and Lal Bahadur but grains contain no such residues. Thin layer chromatographic method was developed to detect residues of the fungicide which was found to be present in straw of sprayed plants of both the varieties. No residues could be detected in grain samples. It was found that triadimefon was converted in triadimenol in/to host.