Furthering our understanding of the interaction of cereal rye allelochemicals with Pythium species and their impact on corn in the cereal rye-corn production system

Aug 2021


Allelopathy is a complex process in which plants release chemical compounds that affect the growth and physiological processes of other plants. Allelochemicals also affect interactions between plants and microorganisms. With previous funding from the Iowa Nutrient Reduction Center (INRC), the researchers showed allelochemicals produced by the cover crop winter cereal rye (CR) reduced corn shoot and root growth in vitro and more severe seedling disease (root rot) was observed when corn was inoculated with some Pythium species.


Researchers will build on their previous research and further our understanding on the interaction of Pythium with rye and corn, thereby answering some fundamental questions regarding this system. This information could be used to identify management practices to help growers avoid corn yield losses following CR without limiting the numerous ecosystem services provided by CR.


The previous studies provided a brief insight into the interaction of allelopathy and Pythium species in the CR cover crop-corn production system, and how they may contribute to reduced yields. Pythium species infect both rye and corn. Moreover, Pythium species are attracted to both hosts by seed and root exudates. Researchers hypothesize that allelochemicals released from decomposing rye residue favor germination and/or activity of Pythium around the germinating corn seed facilitating increased infection of the seedling, which results in poor vigor and corn yield reductions in the CR-corn production system by favoring seedling pathogen-corn interactions and affecting early corn growth and development. This proof-of-concept study will provide further data regarding the interaction of allelopathic compounds and Pythium in a lab-based assay.