NOVEL PERMANENTLY INSTALLED SPRAY DELIVERY SYSTEM FOR IMPROVED PESTICIDE APPLICATION IN SPECIALTY CROPS

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.