Dissertation
AN OPTIMIZED PNEUMATIC SPRAY BASED SOLID SET CANOPY DELIVERY SYSTEM FOR EFFICIENT AGROCHEMICAL APPLICATIONS IN MODERN APPLE ORCHARDS
Washington State University
Doctor of Philosophy (PhD), Washington State University
01/2022
DOI:
https://doi.org/10.7273/000004623
Handle:
https://hdl.handle.net/2376/125278
Abstract
The overall goal of this dissertation was to optimize the pneumatic spray delivery (PSD) based solid set canopy delivery system (SSCDS) for efficient chemical application in tall spindle modern apple orchards typical in Washington state. For a fully functional PSD based SSCDS, the existing reservoir module needed to be redesigned for larger capacity per liner spray length and minimal to no post-spray losses. Thus, as objective I, the reservoir module was reengineered and evaluated with three sizes (1X [370 ml]), 2X [740 ml], and 3X [1,140 ml]) in five SSCDS configurations. The configurations having separate outlet from reservoirs provided lower pressure drop and better spray uniformity. Field trials further confirmed suitability of the 2X and 3X reservoirs with separate outlet configurations. The PSD based SSCDS with 2X reservoir showed comparable spray deposition to airblast sprayer with no significant difference in different canopy zones. However, spray coverage was significantly higher for airblast sprayer potentially due to presence of air-assist. This air-assist may also have contributed to significantly higher spray losses to the ground and aerial drift in airblast sprayer. For PSD based SSCDS, the ground drift was mostly confined within 4.1 m downwind of the sprayed row.
In objective II of this dissertation, biological efficacy of PSD based SSCDS was evaluated towards control of obliquebanded leafroller (OBLR) and codling moth. The studies were conducted using leaf and fruit bioassays using plant tissues collected from the sprayed orchards in a commercial setting. These results were contrasted against an axial-fan airblast sprayer and an untreated control. Similar OBLR and codling moth larval mortality was observed on leaf and fruit bioassays for both the spray systems which was higher than control. Overall, reengineered reservoir module integrated PSD based SSCDS has potential to be adopted in large scale commercial apple orchards. Furthermore, it would potentially reduce the installation and maintenance cost with improved spray performance compared to the prior system.
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Details
- Title
- AN OPTIMIZED PNEUMATIC SPRAY BASED SOLID SET CANOPY DELIVERY SYSTEM FOR EFFICIENT AGROCHEMICAL APPLICATIONS IN MODERN APPLE ORCHARDS
- Creators
- Ramesh Kumar Sahni
- Contributors
- Lav R Khot (Advisor)Sindhuja Sankaran (Committee Member)Elizabeth H Beers (Committee Member)Matthew J Grieshop (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Biological Systems Engineering, Department of
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Publisher
- Washington State University
- Number of pages
- 162
- Identifiers
- 99900901836601842
- Language
- English
- Resource Type
- Dissertation