Allelochemicals from Rye for Weed Suppression.

With the increase in multiple herbicide resistant weeds and the challenge in managing weeds in organic systems, there is a need to improve multi-tactic weed management. Cover crops have played an important role in development of multi-tactic weed management programs with an emphasis on physical weed control and to a lesser extent, phyotoxcity from allelochemicals released during decomposition. While allelochemicals have not been shown to play a primary role in weed suppression in either system, to best exploit this tactic, it is necessary to better understand the interactions between allelochemicals and other weed control tactics. Furthermore, little work has been done to examine the interactions between cover crops, the soil rhizosphere, and bio availability of these allelochemical compounds (benzoxazinoid and phenolics) over time. Therefore, we conducted a study that examines the presence of these chemicals in the soil and the decomposition of these allelochemicals over time. Preliminary results suggest that the concentrations of these compounds are prevalent in three growth stages of the rye, with the concentration varying over time. These results will enhance the understanding of multi-tactic weed management and allow for better comprehension of allelochemicals in weed management.