Thesis
Response of Italian ryegrass to crop rotation and indaziflam in Eastern Washington
Washington State University
Master of Science (MS), Washington State University
2023
DOI:
https://doi.org/10.7273/000005151
Abstract
Italian ryegrass is a troublesome annual grass weed species in areas that receive more than 400 mm of annual precipitation in the dryland wheat production regions of the Pacific Northwest (PNW). Indaziflam has extended residual activity and a novel mechanism of action not available for use in dryland wheat cropping systems. A field study was conducted at two locations (Almota and Pullman) in Eastern Washington from 2020 through 2022 to evaluate crop injury, yield, and Italian ryegrass seedbank response to common wheat rotations with and without indaziflam. Indaziflam was applied postemergence in spring wheat in 2020 at 0, 22, and 44 g ai ha-1. Spring wheat yield was not impacted by indaziflam. In 2021, barley, canola, chickpea, winter wheat, and fallow treatments were established within the 2020 plots. Crop yields were highly variable in Almota, and very low in Pullman due to drought. Barley, canola and winter wheat yields were reduced in plots that were treated with indaziflam in 2020, whereas chickpea yields were unaffected. In 2022, indaziflam treatment was associated with an increase in both winter (Almota) and spring (Pullman) wheat yield. At both locations in 2021, Italian ryegrass plant density, averaged across all crop rotation treatments, decreased with increasing indaziflam rates, with canola and fallow treatments averaging < 2 plants m-2. In 2022, the final year of the study, Italian ryegrass density decreased with increasing rates of indaziflam, although seedbank density was affected by indaziflam rate. In general, indaziflam treatments applied in 2020 that were planted to chickpea in 2021, had the least crop injury and the greatest reduction of Italian ryegrass seedbank density in winter and spring wheat in 2022. Indaziflam appears to be a potentially useful component of an integrated Italian ryegrass management system in dryland wheat production, particularly when rotations include chickpea.
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Details
- Title
- Response of Italian ryegrass to crop rotation and indaziflam in Eastern Washington
- Creators
- Kenton Charles Lyman
- Contributors
- Ian C Burke (Advisor)Drew J Lyon (Committee Member)Timothy C Paulitz (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Crop and Soil Sciences, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University
- Number of pages
- 141
- Identifiers
- 99901019536801842
- Language
- English
- Resource Type
- Thesis