The chapter discusses the importance of reducing herbicide resistance in weeds through best management practices (BMPs). Herbicide resistance is a significant issue in commercial crop production, evolving rapidly due to the selection pressure from modern agricultural practices. The text outlines several key BMPs to mitigate this problem: 1. **Understand the Biology of Weeds**: Knowledge of weed biology, including germination requirements, emergence patterns, reproductive biology, and life cycles, is crucial for effective management. This understanding helps in developing strategies that target specific life stages and reduce the weed seedbank. 2. **Diversified Weed Management**: Diversifying weed control techniques, such as using multiple herbicides with different modes of action (MOAs), mechanical and cultural controls, and integrated weed management (IWM) strategies, is essential to reduce the selection pressure on weeds and prevent the spread of resistance genes. 3. **Preplant Weed Control**: Preplant weed control measures, such as planting into weed-free fields and using residual herbicides, are critical to prevent the introduction of weeds and reduce the risk of herbicide resistance. 4. **Weed-Free Crop Seed**: Planting weed-free crop seed is vital to prevent the spread of herbicide resistance into new areas and to avoid the contamination of crop seed with resistant weeds. The chapter also highlights the challenges in implementing these BMPs, including the economic and practical barriers faced by growers, and the need for education and support to encourage the adoption of these practices. It emphasizes the long-term economic benefits of avoiding the costs associated with managing resistant weeds and the importance of sustainable weed management strategies.The chapter discusses the importance of reducing herbicide resistance in weeds through best management practices (BMPs). Herbicide resistance is a significant issue in commercial crop production, evolving rapidly due to the selection pressure from modern agricultural practices. The text outlines several key BMPs to mitigate this problem: 1. **Understand the Biology of Weeds**: Knowledge of weed biology, including germination requirements, emergence patterns, reproductive biology, and life cycles, is crucial for effective management. This understanding helps in developing strategies that target specific life stages and reduce the weed seedbank. 2. **Diversified Weed Management**: Diversifying weed control techniques, such as using multiple herbicides with different modes of action (MOAs), mechanical and cultural controls, and integrated weed management (IWM) strategies, is essential to reduce the selection pressure on weeds and prevent the spread of resistance genes. 3. **Preplant Weed Control**: Preplant weed control measures, such as planting into weed-free fields and using residual herbicides, are critical to prevent the introduction of weeds and reduce the risk of herbicide resistance. 4. **Weed-Free Crop Seed**: Planting weed-free crop seed is vital to prevent the spread of herbicide resistance into new areas and to avoid the contamination of crop seed with resistant weeds. The chapter also highlights the challenges in implementing these BMPs, including the economic and practical barriers faced by growers, and the need for education and support to encourage the adoption of these practices. It emphasizes the long-term economic benefits of avoiding the costs associated with managing resistant weeds and the importance of sustainable weed management strategies.