Introduction to herbicide metabolism, resistance, and related concepts -- Synthetic auxin herbicide-tolerant crops -- Metabolic degradation of glyphosate in soil microbes, endophytes, crops, and weeds glyphosate metabolism in crops and weeds -- Enhanced metabolic resistance to herbicides in alopecurus myosuroides (black-grass) -- Herbicide detoxification in black-grass -- Metabolism-based resistance in lolium rigidum and raphanus raphanistrum -- Management of metabolism-based resistance in lolium rigidum in Australia -- Metabolic herbicide resistance in echinochloa phyllopogon -- Metabolic resistance to herbicides in echinochloa crus-galli (and colona) -- Metabolic resistance to hppd-inhibiting herbicides in dioecious amaranthus species -- Overview of metabolism-based resistance to ps ii-inhibitors in weed species -- Fitness and eco-physiological cost of metabolic herbicide resistance -- Advancing metabolic resistance characterization: paving the way for future technologies in weed management