Many common agronomic practices affect weed seed dormancy and germination by influencing the microenvironmental and edaphic conditions surrounding seeds in soil. Factors such as light penetration, soil water content, soil fertility, and temperature are modified by tillage, planting, harvesting, and other production practices, resulting in enhanced or depressed weed seed germination. Changes in these environmental factors may also indirectly lead to alterations in phytohormone concentrations during seed development, which can subsequently affect dormancy status of the mature seed. Integrated approaches that place priority on depleting weed seed banks through interfering with dormancy or germination requirements have strong potential to enhance weed management aspects of agricultural systems.

DNA-based molecular markers may provide information about introduced weedy species that would be useful in biological weed control efforts. Chloroplast DNA restriction fragment length polymorphisms (cpDNA RFLP) and random amplified polymorphic DNA (RAPD) analysis are two DNA-based marker techniques that can provide estimates of genetic variation in native and introduced populations of weedy species. Profiles provided by these techniques could furnish the necessary information to determine the geographic origins of introduced species and provide evidence for multiple introductions. Although DNA-based markers would not necessarily identify the genetic basis for host-pest compatibility, they would enable identification of specific host genotypes. Current criteria for selecting a weedy species as a target for biological control are primarily political and economic. The importance of genetic diversity and population structure in determining the vulnerability of plant populations to insects or diseases has not been fully appreciated. Estimates of genetic diversity based on DNA marker analysis could be used as one criteria for determining which plants are targeted for biological control. The success of biological weed control efforts has been limited by the high levels of genetic diversity occurring in target weed specks and the lack of biocontrol agent and target weed compatibilities. DNA-based markers may be used to increase our understanding of these factors and contribute to the success of biological weed control by helping to target the most vulnerable species and provide more realistic expectations of the potential for success given available resources.