Spatial Distribution of Spray from a Solid Set Canopy Delivery System in a High-Density Apple Orchard Retrofitted with Modified Emitters

Rakesh Ranjan; Rajeev Sinha; Lav R. Khot; Gwen-Alyn Hoheisel; Matthew Grieshop; Mark Ledebuhr

doi:10.3390/app11020709

Applied Sciences (Jan 2021)

Spatial Distribution of Spray from a Solid Set Canopy Delivery System in a High-Density Apple Orchard Retrofitted with Modified Emitters

Rakesh Ranjan,
Rajeev Sinha,
Lav R. Khot,
Gwen-Alyn Hoheisel,
Matthew Grieshop,
Mark Ledebuhr

Affiliations

Rakesh Ranjan: Center for Precision and Automated Agricultural Systems, Biological Systems Engineering, Washington State University, Prosser, WA 99350, USA
Rajeev Sinha: Center for Precision and Automated Agricultural Systems, Biological Systems Engineering, Washington State University, Prosser, WA 99350, USA
Lav R. Khot: Center for Precision and Automated Agricultural Systems, Biological Systems Engineering, Washington State University, Prosser, WA 99350, USA
Gwen-Alyn Hoheisel: Center for Precision and Automated Agricultural Systems, Biological Systems Engineering, Washington State University, Prosser, WA 99350, USA
Matthew Grieshop: Department of Entomology, Michigan State University, East Lancing, MI 48824, USA
Mark Ledebuhr: Application Insight, LLC, Lansing, MI 48906, USA

DOI: https://doi.org/10.3390/app11020709
Journal volume & issue: Vol. 11, no. 2
p. 709

Abstract

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Solid Set Canopy Delivery Systems (SSCDS) are fixed agrochemical delivery systems composed of a network of micro-sprayers/nozzles distributed in perennial crop canopies. A previous SSCDS design composed of a 3-tier configuration using hollow cone sprayer nozzles has been shown to provide excellent coverage and deposition in high-density apple orchards. However, the hollow cone nozzles substantially increases the initial system installation costs. This study evaluated the effect of irrigation micro-emitters replacement on spray deposition, coverage and off-target drift. A micro-emitter used in greenhouse irrigation systems was duly modified to enhance its applicability with SSCDS. After laboratory assessment and optimization of the micro-emitters, a replicated field study was conducted to compare 3-tier SSCDS configured with either of modified irrigation micro-emitters or traditional hollow cone nozzles. Canopy deposition and off target drift were evaluated using a 500 ppm fluorescent tracer solution sprayed by the field installed systems and captured on mylar collectors. Spray coverage was evaluated using water sensitive papers. The overall canopy deposition and coverage for treatment configured with modified irrigation micro-emitters (955.5 ± 153.9 [mean ± standard error of mean] ng cm−2 and 22.7 ± 2.6%, respectively) were numerically higher than the hollow cone nozzles (746.2 ± 104.7 ng cm−2 and 19.0 ± 2.8%, respectively). Moreover, modified irrigation micro-emitter SSCDS had improved spray uniformity in the canopy foliage and on either side of leaf surfaces compared to a hollow cone nozzle. Ground and aerial spray losses, quantified as deposition, were numerically lower for the modified irrigation micro-emitter (121.8 ± 43.4 ng cm−2 and 0.7 ± 0.1 ng cm−2, respectively) compared to the traditional hollow cone nozzle (447.4 ± 190.9 ng cm−2 and 3.2 ± 0.4 ng cm−2, respectively). Overall, the modified irrigation micro-emitter provided similar or superior performance to the traditional hollow cone nozzle with an estimated 12 times reduction in system installation cost.

Published in Applied Sciences

ISSN: 2076-3417 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Technology: Engineering (General). Civil engineering (General); Science: Biology (General); Science: Physics; Science: Chemistry
Website: http://www.mdpi.com/journal/applsci

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