Indiscriminate use of herbicides, which appear as residues in soil, water, air and food, is causing potential threat to public life. Pollution free environment is essential for sustaining life on the earth. The use of proper herbicide at the correct dose, at the appropriate time and in the appropriate manner is essential for avoiding any possible build up of toxic residues in the soil. There has been global concern regarding persistence of herbicides in soil. Residues of herbicides applied to the previous crop may adversely affect the succeeding crops in rotation An ideal herbicide should not only provide protection from weeds during critical crop growth period, but also not persist in the soil to harm the succeeding crop or cause pollution. This book deals with degradation and persistence of pretilachlor in soil, plant and water and its residue hazards.