Thesis
Efficacy and economic viability of organically certified herbicides
Washington State University
Master of Science (MS), Washington State University
2019
Handle:
https://hdl.handle.net/2376/101553
Abstract
Organic agriculture suffers from a dearth of cost-effective weed management methods and materials. The difficulty and expense of managing weeds is cited as a major barrier to transitioning into, and profitable management of organic agriculture. Newly registered, organically certified herbicides have entered the market and may help organic producers effectively and economically manage weeds. However, little research has been done on newly registered, organically certified herbicides, and previous research on the prior generation of organically certified herbicides found poor efficacy for weed management. Without proper research on the topic, organic farmers are hesitant to spend money on new products that may or may not work as intended. We hypothesize that newly registered, organically certified herbicides are as effective at removing weed cover as mechanical weed management techniques. Four herbicides certified for organic agriculture were studied, each containing different active ingredients. Two new active ingredients: a mix of capric and caprylic acid (CAP), d-limonene (LIM); and two older active ingredients: a mix of acetic acid and citric acid (ACET), and a mix of cinnamon and clove oil (CIN). CAP provided a mean efficacy rating of 88% in 1 hr and 98% in 72 hr. All materials provided at least a mean efficacy rating of 48% at 72 hr after treatment. Repeated use of CAP and LIM decreased weed pressure at the beginning of the third growing season by 38% and 31% respectively. CAP and LIM were less expensive and as effective at removing weed cover compared to hand weeding. CAP used at 66% of the highest labeled concentration, maintained efficacy and was as effective at removing weed cover compared to hand weeding. Adding an effective organically certified herbicide to existing weed management strategies may allow organic producers to reduce weed pressure, till less often, decrease greenhouse gas emissions, and improve production and profitability.
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Details
- Title
- Efficacy and economic viability of organically certified herbicides
- Creators
- Aaron Blaine Appleby
- Contributors
- Lynne A. Carpenter-Boggs (Degree Supervisor)
- 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; [Pullman, Washington] :
- Identifiers
- 99900525126101842
- Language
- English
- Resource Type
- Thesis