Studies on the fate of isoproturon applied to control Jangli jai (Avena fatua) in wheat (Triticum aestivum)

The fate of the herbicide Isopropturon in the wheat grains, straw, whole plant and soil when applied to control the Jungli jai (Avena fatua) in the wheat field have been monitored. The wheat variety Inqlab was obtained from NIAB Seed Farm and sown in plot size of 0.404 ha. Arelon (45% Isoproturon) at a dose of 3.7 L/ha to control Avena fatua was sprayed in three parts of the plot leaving one part as untreated after 28-30 days of sowing. The wheat grains, straw, whole plant collected after harvest were subjected to qualitative quantitative estimation of Arelon herbicide. The residues Isoproturon in whole plant of 3 months old, grains, wheat straw and soil samples were determined by thin layer chromatography (TLC) and compared with spectrophotometric method. The weed control rating of Isoproturon in control treated plots was observed as highly significantly different from one another. Similarly Isoproturon application has highly significantly increased the grain yield of treated plots. It was more than double as compared to control plot. An ascending order of residues level of Isoproturon was from grains, straw, whole plan and soil samples. The whole plant of treated plot contained 0.67 ug/ml residues of Isoproturon by spectrophotometric method and 0.71 ug/ml by TLC method. The grains of treated plot contained, 0.25 ug/ml by TLC method and 0.27 ug/ml by spectrophotometric method. The wheat straw of treated plots contained, 0.34 ug/ml, and 0.36 ug/ml residues of Isoproturon determined by TLC and spectrophotometric method respectively. The soil collected from treated plots contained 1.73 ug/ml and 1.77 ug/ml residues of Isoproturon determined by TLC and spectrophotometric methods, respectively. Control plots samples of soil contained 0.016 ppm of Isoproturon. It has been concluded that the recommended dose of the manufacturer and amended dose reported in the present study, in the present study have not been successful to completely control the weed (Jangli jai) in the wheat fields. The residual studies indicated that residue levels determined in the wheat grains, straw and whole plant does not exceed permissible recommended by WHO but the chemical, persisted in the samples. The availability of the herbicide residue in the up crop and water during leaching at the time sail of raining and irrigation. It has also been concluded that TLC and spectrophotometric methods are reproducible and comparable for the determination of Isproturon residue in wheat grains, straw, whole plant and soil samples.