Thesis
Assessment of Optical Sensor Sprayer Technology for Application in Eastern Washington Fallow Systems
Washington State University
Master of Science (MS), Washington State University
01/2021
DOI:
https://doi.org/10.7273/000005505
Handle:
https://hdl.handle.net/2376/118902
Abstract
Two studies were conducted near Davenport, WA in 2018 through 2020 to evaluate the efficacy and economic considerations for optical sensor sprayer application in eastern Washington summer fallow. One study evaluated optical sensor sprayer and broadcast applications of bromoxynil + MCPA, glufosinate, glyphosate, paraquat, or saflufenacil + glyphosate. Glyphosate and saflufenacil + glyphosate were effective for control of all target species for both application methods. Glufosinate was not effective for control of any species, though bromoxynil + MCPA or paraquat show potential depending on application method and species present. Optical sensor sprayer treatments were applied at a higher rate, and economic break-even thresholds based on weed cover and broadcast costs are met for each herbicide when weed cover is relatively low. If efficacy of herbicide applications is similar, economic savings can be maximized by applying broadcast rates of herbicides through the optical sensor sprayer. Glyphosate was effective for control of common lambsquarters (Chenopodium album L.), tumble mustard (Sysimbrium altissimum L.), tumble pigweed (Amaranthus albus L.), and prickly lettuce (Lactuca serriola L.). When applied at the broadcast rate through the optical sensor sprayer, glyphosate was the most economical herbicide to be applied with the optical sensor sprayer. The second study was conducted to determine if fallow treatment costs could be reduced when multiple applications are made in a season with the optical sensor sprayer compared to multiple applications with the broadcast sprayer. The greatest economic savings are achieved when glyphosate is applied at a typical broadcast rate compared to increased rates through the optical sensor sprayer. Applications with the optical sensor sprayer are most cost effective when weed cover in a field is low and there is adequate duration between applications to allow weeds to grow to a detectable size for optical sensor sprayer detection. Scouting and accurate estimation of percent weed cover is critical to determine herbicide rate for application in order to reduce herbicide application cost for summer fallow weed management.
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Details
- Title
- Assessment of Optical Sensor Sprayer Technology for Application in Eastern Washington Fallow Systems
- Creators
- Lydia Savannah Fields
- Contributors
- Ian C Burke (Advisor)Drew J Lyon (Committee Member)Tim Prather (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Department of Crop and Soil Sciences
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University
- Number of pages
- 82
- Identifiers
- 99900591958501842
- Language
- English
- Resource Type
- Thesis