Conservation of an endophytic insect-pathogen fungus for plant protection in organic cropping

Farmers and agricultural professionals have great interest in exploiting beneficial soil organisms, especially in organic systems with their focus on soil health and reliance on natural cycles to manage plant health and pests. Endophytes are microorganisms that form non- pathogenic symbioses with plants and can confer benefits including growth promotion and increased plant tolerance to environmental stresses that are predicted to increase with climate change. Our long-term goal is to understand how to promote and conserve the beneficial endemic soil fungus, Metarhizium robertsii, as an insect pathogen and endophyte in organic cropping systems. Within the context of a larger, on-going project to optimize reduced-tillage practices for organic cropping systems, we will utilize field and greenhouse experiments to determine: 1) The in-field prevalence of endophytic Metarhizium in corn grown from Metarhizium-inoculated and non-inoculated seed on three organic farms and in a research-station experiment with three cropping systems that impose a range of soil disturbance; 2) the effects of drought and flooding on establishment of endophytic M. robertsii in corn and resulting effects on plant growth; 3) the effects of the interaction between water stress and endophytic Metarhizium on the black cutworm (BCW, Agrotis ipsilon) and on corn growth. This project leverages and broadens the scope of an on-going multidisciplinary, integrated research and extension organic cropping systems project. We will incorporate our findings into evaluated extension materials and activities to strengthen the capacity of extension and other agricultural professionals to serve the information needs of organic growers.