Wheat is a preferred crop in water limited environments due to its water use efficiency, beneficial residue produced, and ability to produce good yields under a wide range of environmental conditions. Wheat residue can suppress weeds, reduce erosion, increase soil health, capture snow, and enhance precipitation storage efficiency. Production of wheat is being threatened by wheat stem sawfly which cuts the stem near the base and lodges the tiller holding the grain head before harvest. This reduces wheat yield, slows harvest, and greatly diminishes the benefit of the residue. Previous research has found that attributes of the wheat stem wall (thickness) mitigate the impact of the wheat stem sawfly. Even when sawfly pressure is low, increased stem wall thickness and composition increase standability of the wheat before and after harvest, and this could lead to longer-lasting residue and increased subsequent soil water storage and crop yields. This project will evaluate the stem thickness of wheat varieties and how that may reduce sawfly survival and lodging. Furthermore, the project will aim to understand how sawfly infestation may reduce wheat grain yield and quality, residue persistence/degradation, and soil water content and health. More broadly, the implications from understanding stem thickness and its potential impact on soil water can guide breeding and variety selections to impact cropping systems favorably through benefits of strong and persistence of wheat residue. It is anticipated that crop yields of the following crop can be increased when seeded behind a wheat that enhances soil water content. Lastly, the project will evaluate wheat residue characteristics through growing phases until harvest to see if any potential forage benefits exist. These results will be shared widely with wheat producers, wheat breeders, and industry personnel through Extension and outreach efforts.
Project objectives from proposal:
Wheat producers, agronomists, and wheat breeders will gain insight and quantitative metrics into the value of selecting and using wheat varieties with beneficial stem characteristics that reduce susceptibility to wheat stem sawfly and enhance precipitation storage efficacy. Wheat producers who face yield losses from wheat stem sawfly will gain a greater understanding of the impact of the pest on grain yield, harvestability, and wheat residue degradation. Results will be shared through field days, conference presentations, Extension outlets, and peer-reviewed publications. Field days hosted at the on-farm locations will be especially impactful because we plan to include large plot demonstrations.