This is a presentation on the lessons we have learned from testing the Pessl for four weeks in Washington state.
For decades there have been basic principles that all growers know they need to or should follow. Calibration and good coverage are critical. We also know that our canopy shape can change between not only different commodities, but also between blocks of the same commodity. We also know that we should spend more time working on and testing our sprayers, but many other legitimate farm management issues compete for our time and resources. We had this summer to bring up a calibration machine from California to evaluate and examine some of our sprayers.
With the help of numerous organizations, we were funded from the end of May to mid June to test a Pessl. During this brief time we really wanted to evaluate the machine for our future work and see how some of our sprayers are performing.
ThePessl is a European machine that evaluates nozzle output and vertical spray patterns. It evaluates nozzle output on standard nozzles. It also assess vertical spray distribution and finally outputs all this to a computer for reports.
The Instrument has hoses that are attached to the sprayer nozzles, which confines any nozzle output to the test system. Spray that is discharged by the individual nozzles is carried through the hoses to collection tubes where sensors measure the nozzle output over time.
The instrument consists of a 4x15 foot screen with spray collectors to catch the nozzle discharge. The spray emitted from the sprayer is collected in tubes with sensors that measure the amount of spray applied at various height above the ground.
In the summer of 2009, we traveled from Okanagon to Prosser to participate in 4 field days, 16 individual grower calibrations, and work with 1 manufacturer. I had a very limited number of sprayers and this was NOT a rigorous experimental design. I am hoping that you and the people we worked with this summer take this as food for thought on their operations. In the next few slides I will talk about how nozzles and sprayers performed, take this as if you are talking to your neighbor, not rigorous scientific study.
This is a snapshot of the people I worked with and how their sprayers faired. Only 1 airblast sprayer performed the way it should with all nozzles outputing the manufacturers recommendation. On most of the airblast sprayers at least 25-50% of the nozzles were out of the manufacturers range (which we allowed more or less than 20%). Our total range showed that nozzles were either clogged and giving almost half the rate or the discs were worn and the nozzle was giving too much. Many of the producers or managers stated that they did have a regular maintenance schedule, for example cleaning once every 5 sprays, but they still had problems. So it simply allowed them to examine their own practices.
After correcting nozzle output, we could adjust the vertical spray pattern to match the canopy shape of the block. Initial tests only had 3 sprayers (2 airblast, 1 accutech tower) adjusted to the satisfaction of the grower/manager. All other sprayers needed adjustments. This is an example of the spray from a 3-headed accutech tower sprayer. The initial spray is the top picture and the red line just shows the top of the water line in the tube. Here the majority of the spray is being directed at approximately 5-7 feet from the ground. The grower wanted more spray directed in the upper canopy which we achieved after closing bottom nozzles and adjusting the angle of the heads. The result is seen in the lower picture with most of the spray is directed between 7-10 feet above the ground. Depending on the shape of the growers canopy, we would adjust sprayers until they were happy.
Remember limited number of sprayers tested. This is about lessons learned and ways for you to evaluate your performance. Airblast sprayers almost always a bad pattern until nozzles corrected. However, they were easy and intuitiveto adjust direction of spray by simply moving nozzle. Growers could also easily keep track of multiple angles for various shaped canopies with a notch placed on the machine.
The Cropland Tower Sprayer initially should patterns were consistently in a sinus wave,not a bell curve. For one particular grower this was a problem because they had a 2D canopy which meant they really wanted a flat line. The pattern was improved by broadening spray meaning we increased the distance from canopy and angled the nozzles out. It again was fairly intuitive and easy to adjust
6-headed tower sprayers such as Accutechs usually showed a good bell shaped spray distribution that matched the canopy, but they were not always targeted at correct height. They were often confusing to operator on how to adjust spray. Unsure of which valves to adjust and how much. Easy to adjust angle of entire head and of course, no clogged nozzles because of air sheer nozzles.
Excuse the picture here, but the 4-headed adjustable height towers look similar to the 6-heads, without the middle set. I unfortunately didn’t take a picture and couldn’t easily find one. 4-headed tower sprayers such as Accutech & LectroBlasts with adjustable height control. The initial set-up had the heads at maximum distance apart. Despite the visual swirl and appearance of even distribution during spray, maximum head separation resulted in most spray high and low, with very little in the center. A bell shaped spray distribution was achieved by bringing the heads closer together and angling them. We worked so long on one tower sprayer that the grower actually marked and etched the correct distance.
In the past few years there has been a renewal in the interest in application technology. We know we need to do better. Our consumers, our environment, our wallets, and our chemicals demand that we do better. So, there have been a series of meetings to build capacity and interest in this area. Then in October of 2009, we were awarded a grant to develop a national roadmap for research and extension in grapes, tree fruit and nuts.
These planning grants are designed to bring people together to develop a plan of attack for a large problem. We want this to be a collaboration among the people that already work in application technology and bring in new scientists to address key issues.We want the industries to guide our efforts. We do not want to be standing here 30 years from now working on the same problems, because we as academics provided poor solutions to the industryWe have agreed to develop a long term coordinated plan (aka a roadmap) that guides our future research and extension.
Our goals are to identify technology needs, review existing application technologies, identify roadblocks, create a roadmap, and develop full scale proposals.
We basically are soliciting industry input through 3 means. A literature review on existing technologies, a survey that targets large numbers of growers, and lastly focus group meetings and individual conversations.
The most important item is that we need you to guide our efforts. We do not want to create, work on, or waste time on issue not relevant to the industries. 20 years from now we should NOT be discussing this picture and how to reduce drift and the amount of waste on this newly planted vineyard. We want every drop to the crop.I know that I don’t know all the right people
If I have peaked your interest or if you want to give me an ear full. Contact me. I certainly don’t know enough of you and would be interested in listening.
Lessons learned from the evaluation of a Pessl for sprayer calibration
Lessons learned and evaluation of Pessl spray calibration machine<br />Gwen-Alyn Hoheisel<br />WSU Extension<br />Grapes, Tree Fruit, Other Specialty Crops<br />
Background<br />What we know ….<br />Calibration is critical<br />Good coverage is critical<br />Canopy shape can change between crops and blocks<br />We should spend more time on our sprayers, but….<br />
Our Evaluation<br />WSU Pest Management Transition Project<br />May 27-June 19 we tested a Pessl<br />Can it be used in extension/farm operations to calibrate vertical spray patterns?<br />How are some of our Washington sprayers performing? <br />
The Pessl<br /><ul><li>Evaluates nozzle output on standard T-jet nozzles
Assesses vertical spray distribution of any sprayer
Outputs data to a computer where reports can be generated. </li></ul>Make these bullets, just plain apple, cherry or grape<br />
The Pessl<br />Test 1: Nozzle Output<br />Make these bullets, just plain apple, cherry or grape<br />
The Pessl<br />Test 2: Vertical Spray Pattern<br />Make these bullets, just plain apple, cherry or grape<br />Spray 14’ to 20” from ground <br />
Our Evaluations<br />4 Field Days<br />16 Growers<br />1 Manufacturer<br />From Okanagon to Prosser<br />Food For Thought<br />
Grower Calibrations – Nozzles<br />1. Only 1 airblast sprayer had 100% of their nozzles working properly. <br />2. Range from manufacturer specifications = -43.1% to 44.5%<br />3. Even with a defined maintenance schedule still problems<br />
Can easily keep track of multiple angles for various shaped canopies</li></li></ul><li>Remember limited n<br />Sprayer Performance<br />Cropland Tower Sprayer: <br /><ul><li> Initial patterns were consistently in a sinus wave
Pattern was improved by broadening spray (i.e. increased distance from canopy and angled nozzles out)
Fairly intuitive/user friendly to adjust</li></li></ul><li>Remember limited n<br />Sprayer Performance<br />6-headed tower sprayer (Accutech):<br /><ul><li> Usually good distribution, but needed to shift up.
No clogged nozzles</li></li></ul><li>Remember limited n<br />Sprayer Performance<br />4-headed tower sprayers (Accutech & LectroBlast):<br /><ul><li>Initial spray set with heads at maximum distance apart.
Bring the heads closer together. </li></li></ul><li>The Future<br />Development Of A Smart Targeted Spray Application Technology Roadmap For Specialty Crops<br />Hoheisel, Gwen-Alyn-- Washington State University<br />Brunner, Jay-- Washington State University<br />Castagnoli, Steve-- Oregon State University<br />Giles, Ken -- UC Davis<br />Derksen, Rich -- USDA-ARS<br />Landers, Andrew -- Cornell University<br />Niederholzer, Franz -- UC Ag Natural Resources<br />Pitts, Marvin -- Washington State University<br />Zalom, Frank-- UC Davis<br />Zhang, Qin -- Washington State University<br />
The Future<br />An SCRI Planning Grant<br />Bring groups of people together<br />Our thoughts <br />Collaborative Work<br />Ask the Industries to guide our work<br />Develop a long-term coordinated effort for grapes, tree fruit and nuts.<br />
The Future<br />Our Defined Goals in Grant<br />1) identify application technology needs of producers and manufactures;<br />2) review and assess existing application technologies plus relevant or supporting technologies integratable to more efficient application; <br />3) identify roadblocks to adoption of existing application aids;<br />4) create a roadmap for application technology research and extension; and <br />5) develop a full scale proposal for research and extension in FY 2011. <br />
The Future<br />Accomplished by….<br />1. Literature Review<br />2. Survey<br />3. Focus Group Meetings & Other communications <br />
The Future<br />Most Important Item …….<br /> We listen to you.<br />You guide our efforts. <br />