ABSTRACT
Weed seedbanks are dynamic in nature, both temporally and spatially Mathematical models have been used to determine the potential of weed species to contribute to weed seedbank. The concept of a critical period of weed control (CPWC) or critical weed-free period (CWFP) is mainly focused on limiting crop yield loss with less emphasis on weed seed inputs to the soil. Herbicide-based weed management systems generally have a higher weed control efficacy compared to mechanical or cultural weed control systems, and consequently have fewer seed bank additions. The effects of crop rotation on weed seedbanks are mediated by crop sequences that employ varying levels of planting and harvest dates, resource competition, fertility requirements, soil disturbance regimes, crop growth habits, and agronomic or weed management practices. Tillage influences the vertical distribution of weed seeds. The impact of cover crops on weeds can either be in the form of living plants or as plant residue after the cover crop is terminated.
