Environmentally friendly weed management
Agricultural scientists are constantly striving to improve production while reducing costs and negative impacts on the environment. The application of herbicides and pesticides is one of the most detrimental activities associated with large-scale agriculture. The toxins end up in the harvested crops, the soil, the groundwater and can even be resuspended into the atmosphere. Sponsored by the LIFE QUALITY Programme, the FATEALLCHEM consortium took up the search for more friendly approaches to controlling weeds. Their research focused on evaluating the ability of allelopathic substances, naturally occurring plant toxins, to combat weeds. The effects of two allelochemicals, the benzoxazinones DIMBOA and DIBOA, on both crops and weeds were studied in detail. The FATEALLCHEM coordinator, the Danish Institute of Agricultural Sciences (DASI), supervised the experiments. Data on germination, shoot growth and root growth was collected in the field. Reductions in root growth rates were observed, but the application of allelochemicals had little impact on limiting germination. Once introduced to the soil environment, DIMBOA and DIBOA break down into metabolites. It was found that some of these metabolites, such as APO, exhibited even higher levels of phytotoxicity. Finally, contrary to popular belief, DASI did not detect any positive combined effect of DIMBOA, DIBOA and their metabolites. These initial results justify the need for further investigation before proceeding with any program of weed control based on these allelochemicals.
