Answering grower questions on new
sprayer technology at Sunbelt Expo
BY SIMERJEET VIRK
University of Georgia
SPRAY TECHNOLOGIES HAVE advanced considerably over the lastfew years. Growers now have multiple options to choose from forboth their old and new sprayers, and they have questions on whatthe best options for them are.
Some of the common grower questions regarding pesticideapplications still revolve around selection of optimal spray parameters such as nozzle type, spray volume, spray pressure and droplet size so they can make more effective pesticide applications whileminimizing off-target movement. All these are important questions.
Crop protection chemicals are expensive. With recent dicamba registration issues, we fully understand the importance of keeping pesticide applications on target while being more effective and efficientwith each application to stay on top of pest control.
To provide research-based answers to these grower questions,the University of Georgia is conducting multiple research studies funded by the Georgia Peanut Commission, National PeanutBoard, and Cotton Incorporated. Two of these studies are beingconducted at the Sunbelt Ag Expo Darrel Williams Research Farmand were showcased at the Expo’s annual field day, which went virtual this year due to excessive wet weather.
In our first study, we are comparing spray coverage and efficacyof three different nozzle types commonly used by cotton and peanut growers, the Teejet standard flat-fan extended range XR, theair induction extended range AIXR, and the Turbo TeeJet InductionTTI, all three at three spray volumes of 10, 12. 5 and 15 GPA.
In this study, the primary difference between all three nozzlesat a given spray volume is the droplet size, which is an importantapplication consideration as it affects both coverage and off-targetmovement.
Generally, smaller (fine to medium) droplets are needed forincreased coverage, however they are also more susceptible toincreased spray drift potential. Therefore, larger (very coarser toultra-coarse) droplets are recommended where spray drift management is important, such as when spraying dicamba or 2,4-D.But larger droplets can result in reduced coverage and provide less-effective pest control, especially when spraying contact pesticides.
Changing nozzles between crops and spray applications is notcommon. Once a grower selects a certain nozzle, there’s a goodchance it is going to stay on that boom for the rest of the season.
Recently, growers are also trending towards spraying lower volumes to cover more acres; however, lower-than-recommendedvolume can influence coverage and pest control.
From this study, we plan to provide research-based recommendations to growers on selection of spray parameters as well as considerations on how they can utilize this information for their specific pesticide applications. As much in everything farming, the“one size (nozzle or volume in this case) fits all” approach does notapply here as well when it comes to pesticide applications.
The second study focuses primarily on investigating how precision spray technologies such as PWM nozzles or auto-boom heightcontrol system can help improve on-target applications whilereducing off-target pesticide movement.
The individual PWM nozzle system overcomes a major limitation of pressure-based, rate-control systems and provides anadded functionality of maintaining constant spray pressure acrossthe boom independent of ground speed changes in the field. Maintaining constant pressure is very important for consistent dropletsize and spray application uniformity throughout the whole field.Similarly, auto-boom height systems can automatically adjustboom height in real-time during application, keeping consistentspray overlap and uniformity across the field.
In this study, we are assessing spray coverage, application uniformity and spray particle drift at different ground speeds andboom heights with a Case IH 3340 sprayer provided by Southeast Ag Equipment and Case IH equipped with an individual PWMnozzle control and an auto-boom height control system. Some ofthese new spray technologies come at a considerable cost to growers so this research is much needed to understand the associatedtechnology benefits and if the extra cost in precision technologiesis worth the investment for growers or not.
This sprayer research taking place at the Sunbelt Ag Expo is partof the UGA Extension SMAR T Farm initiative. SMAR T stands for Simple, Measurable, Applied, Relevant and Timely research. It includesvarious projects focused on grower-driven research across thestate to help answer basic agronomic or management questions.
Research takingplace at theSunbelt Ag Expois part of theUGA ExtensionSMART Farminitiative. SMARTstands for Simple,Measurable,Applied, Relevantand Timelyresearch.
Case IH Patriot 3340 equipped with Pulse Width Modulation nozzlesand auto-boom height control system used for research studies at theSunbelt Ag Expo farm.