Non Technical Summary
Growers want the ability to spray an orchard or protected agriculture installation without being in it. Driving row middles to apply spray is a difficult and highly time-sensitive activity that compacts soil, damages crops from machinery contact, and requires larger, more powerful and costly tractors than most other orchard processes. It may be required upwards of 30 times a year (Becerra et.al. 2010, Håkansson et.al. 1988). Passage of these tractors and sprayers requires valuable land for the drive rows that might otherwise be planted. In adverse weather conditions tractor passage may be impossible due to mud. Removing the need to drive every middle with a sprayer could allow extra farmable area from removed or reduced drive middles. This is like getting up to 20% more farmable space for nothing, corresponding to a 20% increase in gross revenues from the additional yields.?In protected agriculture (PA), pesticide application is often tedious handwork of dubious quality that puts humans in close contact with the spray process, a worker protection risk. Permanent installation of application technology offers growers the opportunity to eliminate all these problems with a fast, simple process. The concept of such an installation is generally called a Solid Set Canopy Delivery System (SSCDS). Simply stated, it is a high density orchard (HDO) open-field planting (most commonly apples), or PA installation such as a high tunnel, hoophouse, greenhouse, or other indoor grow facility that is permanently plumbed with the means to spray the crop. (Panneton et al., 2011, 2015, Neimann et al., 2014, Lombard et al., 1966, Verpont et al., 2105) Blocks of one or more rows are sprayed sequentially from the headlands by either a mobile cart (Greishop et al., 2015) or permanently plumbed control infrastructure in the orchard (Ranjan et al., 2019). Application times for SSCDS systems can be significantly shorter, requiring 30% of the time a driven sprayer requires. The application is fast, effective, and can result in spray drift reductions of up to 80% (Sinha et al., 2019, Greishop et al., 2019) There is high interest in this technology: More than three out of five Great Lakes apple growers identified SSCDS as a research area of high priority (Ledebuhr, pers. comm. 2016). The letters of support from TRICKL-EEZ and multiple chemical suppliers shows that the supply and support industries are also interested. There are now over 15 years of field research funded by multiple SCRI grants that prove SSCDS is fundamentally a safe and effective means to apply pesticides (Agnello et al., 2006, Owen-Smith et al., 2019, Greishop et al., 2018). Adapting hardware designed for irrigation to the much more demanding task of applying pesticides has identified many technology challenges. (Agnello et al., 2006, Sharda et al., 2013) Some, such as improved nozzles, have been solved (Sinha et al., 2019 and Guler et al, 2020). Others, such as unused drainable volume, cost of installation and operation, and long-term system reliability in the face of residues and environmental variability, have persisted, but will be solved by this project. Proof-of-principle work on what we call the "Z-system" has been successful. In this project it will be validated as suitable to the needs of HDO and PA growers, who need a design that will operate reliably, repeatedly, without maintenance, through heat and freeze-thaw cycles, for at least five years in field installations.PA is critical for future growth of many fruits and vegetables as it increases the growing season, reduces water use, and increases yields over field grown crops. When growing areas are sealed or screened, it eases control of insects and improves spray application conditions. Increasing the productivity of these cultivation systems will improve their economic viability and accelerate adoption. Increased adoption of PA will have the societal benefit of increasing the resilience of our food production and distribution network.

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
204	1199	2020	100%

Knowledge Area
204 - Plant Product Quality and Utility (Preharvest);

Subject Of Investigation
1199 - Deciduous and small fruits, general/other;

Field Of Science
2020 - Engineering;

Goals / Objectives
Growers want the ability to spray an orchard or protected agriculture installation without being in it. Driving row middles to apply spray is a difficult and highly time-sensitive activity that compacts soil, damages crops from machinery contact, and requires larger, more powerful and costly tractors than most other orchard processes. It may be required upwards of 30 times a year (Becerra et.al. 2010, Håkansson et.al. 1988). Passage of these tractors and sprayers requires valuable land for the drive rows that might otherwise be planted. In adverse weather conditions tractor passage may be impossible due to mud. Removing the need to drive every middle with a sprayer could allow extra farmable area from removed or reduced drive middles. This is like getting up to 20% more farmable space for nothing, corresponding to a 20% increase in gross revenues from the additional yields.In protected agriculture (PA), pesticide application is often tedious handwork of dubious quality that puts humans in close contact with the spray process, a worker protection risk. Permanent installation of application technology offers growers the opportunity to eliminate all these problems with a fast, simple process. The concept of such an installation is generally called a Solid Set Canopy Delivery System (SSCDS). Simply stated, it is a high density orchard (HDO) open-field planting (most commonly apples), or PA installation such as a high tunnel, hoophouse, greenhouse, or other indoor grow facility that is permanently plumbed with the means to spray the crop. (Panneton et al., 2011, 2015, Neimann et al., 2014, Lombard et al., 1966, Verpont et al., 2105) Blocks of one or more rows are sprayed sequentially from the headlands by either a mobile cart (Greishop et al., 2015) or permanently plumbed control infrastructure in the orchard (Ranjan et al., 2019). Application times for SSCDS systems can be significantly shorter, requiring 30% of the time a driven sprayer requires. The application is fast, effective, and can result in spray drift reductions of up to 80% (Sinha et al., 2019, Greishop et al., 2019) There is high interest in this technology: More than three out of five Great Lakes apple growers identified SSCDS as a research area of high priority (Ledebuhr, pers. comm. 2016). The letters of support from TRICKL-EEZ and multiple chemical suppliers shows that the supply and support industries are also interested. There are now over 15 years of field research funded by multiple SCRI grants that prove SSCDS is fundamentally a safe and effective means to apply pesticides (Agnello et al., 2006, Owen-Smith et al., 2019, Greishop et al., 2018). Adapting hardware designed for irrigation to the much more demanding task of applying pesticides has identified many technology challenges. (Agnello et al., 2006, Sharda et al., 2013) Some, such as improved nozzles, have been solved (Sinha et al., 2019 and Guler et al, 2020). Others, such as unused drainable volume, cost of installation and operation, and long-term system reliability in the face of residues and environmental variability, have persisted, but will be solved by this project. Proof-of-principle work on what we call the "Z-system" has been successful. In this project it will be validated as suitable to the needs of HDO and PA growers, who need a design that will operate reliably, repeatedly, without maintenance, through heat and freeze-thaw cycles, for at least five years in field installations.PA is critical for future growth of many fruits and vegetables as it increases the growing season, reduces water use, and increases yields over field grown crops. When growing areas are sealed or screened, it eases control of insects and improves spray application conditions. Increasing the productivity of these cultivation systems will improve their economic viability and accelerate adoption. Increased adoption of PA will have the societal benefit of increasing the resilience of our food production and distribution network.

Project Methods
Technical Objective 1:To demonstrate the Z-System's reliability and durability over an amount of cycles equivalent to five years of use. Acceptance Criterion: <10% valve failure over the course of 150 cycles spread out over the course of a month in batches of 30 per day.Rationale: The Z-System must be reliable enough to work largely without fail for the technology to be cost-effective to the grower. Since the failure of a valve set equates to a permanent loss of pesticide application to a corresponding length of row, there can be little if any tolerance for failure. There is no path to commercialization without a reliable system. The acceptance criterion for this TO is based on an average of 30 spray cycles per year over 5 years.Experimental Design & Methods:Task 1: Install Z-System array. An array representing a complete row (30 valve sets representing 240' of row) will be installed.Task 2: Run trials consisting of 150 cycles in batches of 30 cycles per day for one month.. Capture volume of each end nozzle in a calibrated container, measure and record.Task 3: Analyze collected data. Analyze modes of failure for any valve set that has fallen out of parameter. If total number of valve failures exceed the TO threshold, analyse failure modes and attempt design improvement to mitigate. This will happen in-process with improved hardware, i.e. the complete number of cycles will not be repeated. In the case of a mass failure more than halfway into the TO 1 phase of the evaluation, once the solution to the failure is engineered and implemented, we will attempt to add additional replicates to go into the winter with a completed set of cycles. Given the project seasonality this may or may not be possible.Data Analysis & InterpretationValve is considered failed if it fails to cycle with an output within +/- 10% of the Coefficient of Variation of the rest of the array.Potential Pitfalls / Alternative ApproachesThe largest potential pitfall during this trial is failure of valves. Typical failure modes of plastic valves in other mobile sprayer applications are stiction, or the tendency of plastic parts to lightly stick together and require higher breakaway forces before sliding or separating. This can be due to residues in the system, interactions between the sealing parts in the plastic, or other dimensional changes that would affect the way parts fit together and interact. Given the low operating pressures and spray application volumes, there is so little energy in the system to actuate the valve motions that this is our primary design concern and all designs have been made to minimize the effects of stiction. Stiction and non-uniform spring force of check valves has been the most common mode of failure to date in the SSCDS program with the commercial irrigation components used. Other possible failure modes are cracking due to freeze or other stresses, and dimensional changes that prevent the valves from operating normally due to change in temperature or chemical incompatibilities. The dimensional stability over temperature issue is another real concern for reliable operation, and one of the reasons that this SBIR investigation in actual atmospheric conditions is so important. By using polypropylene and polyethylene, two plastics with high lubricity, chemical stability, and virtually zero water absorption, along with careful attention to the intrinsic design features we have studied and refined to date, we expect to have minimal potential for these failure modes. If data shows an initial rate of valve failure above our accepted level, we will assess the failure (material, mechanical design, improper installation, etc.), correct the situation if possible, and continue the tests. The additional replicates in TO 2 will validate the improvements.Expected OutcomesAt the conclusion of Technical Objective 1, we will have demonstrated that the Z-System is durable and reliable enough to be used for at least five years of use (150 cycles) without significant valve or other mechanical failure.Technical Objective 2To demonstrate the Z-System's durability after a period of seasonal disuse in a harsh winter climate. Acceptance Criterion: >90% valve functionality immediately upon spring start-up.Rationale: The Z-System must be able to lie unused in a field installation through a typical winter season in northern states and function with little to no failure at the start of the next spraying season.Experimental Design & Methods:Task 1: Perform final spray and rinse in fall as per normal use patternTask 2: Allow system to remain unmaintained throughout the winterTask 3: Run at least 1 set of 30 standard spray cycles in spring, same protocol as for TO 1. If TO 1 resulted in >10% failure and a solution was implemented, run additional spray cycles to make up the lost difference up to 150 using same protocol as TO 1.Task 4: Analyze data.Data Analysis & Interpretation• Data interpretation will be straightforward. Volumetric measurement of each valve set will be determined at every cycle. Coefficient of variation ((SD/x?) * 100) will be determined between all the valves in a given cycle, and for each valve over its series of cycles. Any variation outside of a 10% CV will trigger engineering analysis to attempt to understand the source of error, then further engineering to correct if necessary and possible. Success will be the achievement of indicated number of cycles within indicated CV's..Potential Pitfalls / Alternative ApproachesThe pitfall at this stage is that the system does not function properly. Given the success in the MTRAC work, we feel it is unlikely that failure will occur on the fall tests. Success at that stage means that it is highly likely that the system will at least be suitable for a portion of, if not all PA applications. The overwintering tests are where we feel the highest likelihood of failure are, and success in resisting extreme weather is critical for high tunnel and open field uses where multiple freeze-thaws are likely. Should the system fail in the spring tests, the failed parts would need to be examined for cause of failure and a decision made regarding re-engineering and re-testing. Success in TO 1 is adequate to move the project forward to Phase II as a substantial path to commercialization exists, but the market will potentially be much bigger if both TO 1 and TO 2 are achieved. If we feel we can overcome the mode of failure in TO 2 with more testing, which will be impossible to do within the time allowed, we would propose to continue that development as part of the Phase II application.Expected OutcomesAt the conclusion of Technical Objective 2, we will have demonstrated that the Z-System can operate within a reasonable operational life and be left installed and dormant for a harsh northern winter, then still function reliably without further attention in the spring.