Integrating Genetics and Weed Management

Weeds are a major problem on organic farms, where ecological weed management without the use of synthetic chemicals is challenging and strategically different from traditional farming practices.  Impacts of invasive species and weeds are also expected to rise in response to climate change.  In an effort to develop more efficient weed management strategies, we must gain a better understanding of the current biodiversity of these weed species.  Ten of the most problematic weed species in Northern New England (NNE) were selected for genetic analysis based on a survey of organic farms in NNE.  Genetically, little is understood about the weeds that inhabit NNE, their patterns of evolutionary change, or their responses to environmental selection pressures.  Developing strategies to both predict and reduce the impact of invasive weeds will help farmers save money and resources in weed management.  The objectives of this research are to: 1) Genetically characterize problematic weed species of interest in NNE; and  2) Assess the biodiversity among and within weed species at multiple sites in NNE.  Genome size is being determined using flow cytometry procedures to calculate the C value(s) of each species.  Genetic variation within each species is being measured using high-throughput genotyping.  Collaborative efforts with the University of Maine and University of Vermont will also use these genetic results to correlate genetic biodiversity with seed bank and climate data analysis.  Results from this research will help move the field of ecological weed management forward by gaining a better understanding of the genetic structure and potential for evolutionary success of current weed populations in NNE.