Thesis
Impacts of agronomic practices on insect pest populations in quinoa
Washington State University
Master of Science (MS), Washington State University
12/2019
DOI:
https://doi.org/10.7273/000003992
Handle:
https://hdl.handle.net/2376/124233
Abstract
Farming practices can be manipulated to increase crop yield, reduce pests, and suit production to different climates. However, management of newly introduced crops is difficult when pest complexes and their interactions with agronomic practices are unknown. Quinoa is a relatively new crop to North America, and little research has been done to identify insect pests and how they are impacted by management practices. Here, I demonstrate how several common agronomic practices influence insect pest population dynamics in quinoa in Washington State, USA. First, I identify the main pest complex of quinoa in Eastern WA. I found that Lygus spp. (Hemiptera: Miridae) and Aphis craccivora (Hemiptera: Aphididae) were the most abundant insect pests in the field in 2017 and 2018. I then assessed the effects of irrigation, planting method, and quinoa variety on the seasonal pest population dynamics of Lygus. Agronomic practices had a significant impact on pest abundance, but these effects varied among seasons. Both irrigation and direct seeding had reduced insect pests. Overall, the study shows that planting method and irrigation regime may be important components of pest control. Next, I characterized the impacts of organic and synthetic fertilizer and quinoa variety on pest population growth and survival. In cage settings, organically fertilized quinoa supported lower aphid and Lygus populations than quinoa grown with synthetic or no fertilizer. The quinoa variety Cherry Vanilla also had lower pest populations than variety Titicaca. These results suggest that fertilizer regime and variety may be an important tool in effective pest control, and growers should consider using organic fertilizer. My results indicate the importance of manipulating agronomic practices to reduce insect pest populations and influence their dynamics in new crops.
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Details
- Title
- Impacts of agronomic practices on insect pest populations in quinoa
- Creators
- Elisabeth Constance Oeller
- Contributors
- David William Crowder (Advisor) - Washington State University, Department of Entomology
- Awarding Institution
- Washington State University
- Academic Unit
- Department of Entomology
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University
- Identifiers
- 99900890798101842
- Language
- English
- Resource Type
- Thesis