Plant pathogens — microorganisms and other disease-causing agents — can wreak havoc on agricultural and forest crop plantings, as well as rangeland.

Managing annual monoculture crops to resist disease means using specific products or practices to disrupt the pathogen population.  

But researchers think an altogether different strategy could work in an alternate system: perennial polyculture. 

University of Kansas scientists and their collaborators believe, based on their previous research, that this approach could lead to more durable resistance in perennial crops: mimicking nature and using mixed strategies — including breeding for resistance and planting in multispecies polycultures. 

A new five-year, $2.5 million grant will support a KU-led project exploring this approach in a potential perennial oilseed crop, silflower (Silphium integrifolium). The project is funded through the federal program on Ecology and Evolution of Infectious Diseases (EEID), a joint effort of the National Science Foundation, the National Institutes of Health and the U.S. Department of Agriculture.

The principal investigator is Jim Bever, KU Foundation Distinguished Professor of Ecology & Evolutionary Biology and senior scientist at the Kansas Biological Survey & Center for Ecological Research. Collaborating institutions are The Land Institute in Salina, the Danforth Plant Science Center in St. Louis and Case Western Reserve University in Cleveland.

“We already know that the impact of pathogens goes down with species diversity in plant communities,” Bever said. “This is common in prairie plant communities, and it brings significant increases in productivity. In terms of a crop, that means overproducing.”

Researchers will evaluate the drivers of foliar disease in silflower — specifically the relative importance of two factors: breeding for genetic resistance and planting in multispecies mixtures. The results could guide future breeding efforts and planting designs. 

“My hope and expectation is that planting diverse species mixes can mean more robust resistance to pathogens than you’d get only using a genetic approach,” Bever said. “Reliance only on breeding for resistance is hard because you’re only addressing one pathogen at a time, and the pathogen is always evolving.

“Diversity in planting can give plants resistance to more pathogens at once, and that can make resistance more difficult for the pathogen to overcome. So it follows that planting diverse mixes also could reduce the need to put effort into breeding for pathogen-specific resistance.”

The project runs from the beginning of 2025 through the end of 2029, with field research sites in Lawrence and Salina. 

The Kansas Biological Survey & Center for Ecological Research is a KU designated research center, housing a diverse group of programs in ecological research and remote sensing/GIS. It also manages the 3,200-acre KU Field Station, a resource for KU studies in the sciences, arts, humanities and professional schools, and for the community and other institutions.

Source - https://news.ku.edu