Location: Integrated Cropping Systems Research
Project Number: 3080-21220-005-00-D
Project Type: In-House Appropriated
Start Date: Jan 26, 2011
End Date: Oct 25, 2015
Objective 1: Determine the biological, ecological, and behavioral basis that underlie insect pest (e.g, corn rootworm) resistance to management tactics (including GM crops), and develop novel crop and pest management technologies that enhance development of insect resistance management (IRM) plans. • Sub-objective 1a. In relation to IRM, determine whether resistance to Cry3Bb1 affects the mating behavior and reproductive biology of western corn rootworm. • Sub-objective 1b. Develop rootworm strains resistant to additional Bt corn events and assess trajectory of resistance development and its implications for rootworm fitness. Objective 2: Develop non-chemical tools (e.g., host-plant resistance and biological control) for managing corn rootworms and other insect pests, and devise effective approaches to integrate them into corn production systems. • Sub-objective 2a. Advance germplasm with resistance to corn rootworm larval feeding. • Sub-objective 2b. Identify Quantitative Trait Loci (QTL) associated with reduced damage in rootworm-resistant corn lines. • Sub-objective 2c. Assess the feasibility of winter cover crops as a method for increasing biological control of corn rootworms. Objective 3: Develop strategies to integrate non-chemical weed population management into crop rotation systems and identify environmental and physiological factors that limit the effectiveness of key granivores to regulate weed populations. • Sub-objective 3a. Develop a rotation design that reduces weed community density in organic croplands. • Sub-objective 3b. Evaluate contributions of cultural practices and granivory to weed seedling emergence in soybeans. Objective 4: Examine how herbicide tolerant and insect resistant crop varieties affect multitrophic relationships among soybeans (and other crops), insect pests, and natural enemies. • Sub-objective 4a. Identify and characterize soybean germplasm that is resistant to the soybean aphid. • Sub-objective 4b. Determine the implications of glyphosate-tolerant soybeans on biodiversity and its contributions to biological control of soybean aphids.
Sustainable pest management ultimately involves applying ecological principles for reducing insect and weed pressure on key crops. Our project couples bottom-up and top-down processes to reduce key pests (corn rootworms, soybean aphids, and weed communities) of Northern Great Plains crops in agronomically feasible ways that mimic those that regulate pest species within natural habitats. In corn, we will identify lines with natural resistance to rootworms, and will find quantitative trait loci to facilitate their use by seed companies. We also will incorporate winter cover crops into corn production systems in ways that encourage endemic predator communities and increase their impact on rootworms. Fitness-related traits that influence the evolution of rootworm resistance to Bt corn will be identified, and this information will be incorporated into insect resistance management decision-making tools in order to preserve this pest management technology. In soybean, we will discover new soybean lines that express resistance to a key pest, the soybean aphid. Simultaneously, we will determine how to manage non-crop vegetation within soybean fields to promote aphid natural enemies. Weeds are well adapted to current crop rotations, and our research will optimize crop rotations using population-centered approaches that break the weed cycle and increase the impact of insect granivores on weed seedbanks, especially within organic systems. The simultaneous development of top-down and bottom-up mechanisms for pest management are incorporated into sustainable and integrated pest management systems to provide producers with profitable pest management solutions that can be realistically implemented on their farms.