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GPS Sprayer Demonstration

July 15, 2011

Turf managers have curiously watched and anxiously waited for technology currently used in agriculture to be scaled down for utilization in turf.  GPS and auto steer on tractors, combines, and sprayers have allowed farmers to navigate fields for better coverage in less time, perform site-specific management, accurately monitor yield, increase spray efficiency, reduce fuel consumption, and even work through the night.

It was only a matter of time.  Iowa State Turfgrass researchers have performed a dual demonstration of GPS turf-sprayer technology at the Horticulture Farm.  The results of the demonstration will be on display at the Iowa Turfgrass Field Day on July 21, 2011 at the Iowa State University Horticulture Research Station.   

The objective of the dual demonstration was to test the accuracy of the GPS sprayers.  Two simulated “greens” were outlined in spray paint and glyphosate was applied by two different sprayers within the two painted areas.  The premise was easy: kill the grass inside the spray paint.  The task, however, was much more difficult. 

Steve Willey of Capstan Turf Systems brought out a Toro sprayer outfitted with Capstan's sprayer technology for the trial.  Capstan offers three modules of aftermarket technology, and all three were used during the demonstration.  Click here to learn more about Capstan and their products.

Van Wall John Deere retrofitted a sprayer for Tim Van Loo of ISU Athletics with GPS technology for use on Iowa State's athletic fields.  Mr. Van Loo repeated the process for the second part of the demo.  Van Wall's website can be accessed here.

Keep in mind the two sprayers used in the demonstration weren't exactly the same units and that this was not a head-to-head competition.  Reel and rotary mowers work differently and so do these sprayers.  This demonstration was merely a showcase of GPS sprayer technology that is available.  

Watch a short video below to see the Capstan sprayer technology in action.  The sprayer demonstrations and companies involved in will be in attendance at the Turfgrass Field Day.

Quincy Law

ISU Turfgrass Research Associate




Iowa Turfgrass Field Day Recap, Part 2

July 28, 2011

Below is the second part of the 2011 Iowa Turfgrass Field Day Recap. This article highlights talks focusing on summer seeding methods, updates on moss and algae control on putting greens, apps for turf managers and GPS spraying.

Summer seeding: During this talk, some of the ideas about seeding rates and timing were discussed to give turf managers more tools when deciding when to seed, for what purpose, and how much to seed during different times. The philosophy and science behind traditional seeding rates and higher than normal rates were discussed and a demonstration was in place to show what different seeding rates look like as well as ways to determine how much seed you are putting out without properly calibrated equipment. Lastly, we discussed how higher than normal seeding rates can reduce herbicide inputs by outcompeting weeds.

If you ever need to determine how much seed you have put out, there is a simple rule you can follow. If you are sticking to normal seeding rates (1.5 lbs/1000 ft2 for KBG; 8 lbs/1000 ft2 for PR and TF), you can always pick out a 1 square inch area and could how many seeds you see. You should count somewhere around 16 seeds in a square inch for either of the seeding rates listed above.

Higher than normal seeding rates are necessary when we introduce cleated traffic to a turf stand. We don’t hesitate to recommend turf managers putting out an initial rate of at least 20 lbs/1000 ft2 when starting from bare ground to get as much wear tolerant biomass established as possible before traffic starts. This method of seeding at higher rates can also result in an essentially weed free stand of grass, especially with a quickly establishing grass like perennial ryegrass.

Moss & Algae control: Dr. Minner gave a good overview of the different types of moss and algae that can inhabit bentgrass putting greens, or anywhere conditions are right for their growth and development (wet, low mowing height, high N). He also showed preliminary results of a study that uses different methods and chemicals to control silvery thread moss on greens. Two products, MossBuster, and QuickSilver herbicide (carfentrazone), which has labeled rates and instructions for silvery thread moss control, are being evaluated both in combination with each other and on their own at different rates to determine the most effective control of silvery thread moss.

The main problem with the MossBuster product is that it can have an extremely phytotoxic effect on bentgrass, however, it is extremely effective in killing silvery thread moss. Conversely, QuickSilver is effective, but not as effective as MossBuster at finishing off moss populations. So far, a low rate of MossBuster combined with a low rate of QuickSilver, applied frequently (1 week apart), has shown the least phytotoxicity and the moss control is on par with higher rates of each product in combination or on its own. This study is still relatively new and we will continue to monitor the effects of each treatment.

Apps for turf managers: Dr. Marcus Jones has been watching the turfgrass technology front very closely over the past few years and was able to give attendees a short discussion on a relatively new ‘App’. The iStimp is an app that claims to act as a stimp meter on golf greens and is available for Apple devices including the iPod touch, iPhone, and iPad.

Essentially, you set the ball in the small divot of the ‘home’ button on the iPhone, set it on the ground, and lift up until the ball starts to roll. Once the ball has rolled its distance, you use a built in ruler to measure the distance. The phone then calculates what the reading would be on a regular stimp meter. Dr. Jones is working on a research project that will test the effectiveness of this app when compared to the traditional stimp meter. Keep tuned to the iaTURF blog for updates on this project.


GPS spraying: GPS based technology has been around the agriculture field for a few years now and it’s slowly starting to creep its way in to the turf industry. We were fortunate to have a few of the current models on the market present at field day this year. We also saw a demonstration of how the technology works; the sprayer can minimize drift, minimize overlap, steer itself, calculate exact rates of application, and many other things. It’s truly an amazing technology and it probably won’t be long before everyone has some sort of experience with one of these machines.


If anyone has any questions or comments about Field Day 2011, please feel free to contact me, Andrew Hoiberg ( or any of the other speakers. This truly was one of the best field days I’ve been a part of and we owe it to a great turfgrass industry in Iowa. Thanks to the vendors and attendees for a wonderful day! We’ll see you next year!

Andrew Hoiberg
Graduate Student
Iowa State University



August 10, 2011

The following is a post from Zach Simons. Zach is working on a masters degree through the master of Ag. program with a specialization in turfgrass science. He is working this summer with Dr. Van Cline at Toro in Minneapolis on a very interesting project that involves the mapping of soil conditions in turfgrass areas using remote sensing and GPS (global positioning system) technology. This is part of his creative component for his MS degree.

If you get Golf Course Management, you will find an article on this technology by Dr. Cline and Dr. Carrow of the University of Georgia in the August issue.

From Zach:
The increased emphasis on reducing water usage in the turf industry has increased the need for site-specific management. Toro has been developing a product called the Precision Sense 6000 (PS 6000) that can give site-specific soil information in turfgrass. The PS 6000 is a mobile sensing machine that measures soil moisture, soil salinity, soil compaction, and turf vigor. It is designed to be used on golf course fairways and athletic fields. A sensor that measures soil moisture, soil salinity, and soil hardness is attached to a rotating arm on the machine. A spectrometer measures the turf vigor by measuring reflected energy from the turf canopy at a wavelength in the red area in the visible spectrum and a wavelength in the near infrared portion of the spectrum.

The PS 6000 is pulled by a heavy-duty workman set to a speed of 1.9 miles per hour (mph). The machine moves at a speed of 1.9mph so samples are taken every 8 feet with a spacing of 8 to 12 feet between adjacent passes. Data on an average par 4 fairway can be collected in 45 minutes and it takes a day and a half to 2 days to collect data on an entire golf course.

A GPS system is used on the PS 6000 to give the specific site where data was collected. Once the data is collected and processed the results are displayed on Google Earth. Google Earth allows a person to zoom in on a specific hole on the course to analyze the data. Multiple layers can also be displayed on Google Earth so a person could compare the relationship from soil compaction to soil moisture.

Data collection with the PS 6000 should occur at a time when the golf course or athletic field is relying on the irrigation system to water the turf. This is so the data collected reflects the coverage of the irrigation system. When data is collected at that time, it can show areas on fairways that are getting over-watered or under-watered by the irrigation system. An irrigation audit can be performed with the data collected. The audit is performed by determining if the soil has the desired volumetric water content from irrigation. The audit can show many irrigation heads around the golf course that may have problems and the superintendent can make the proper adjustments.

The service that the PS6000 provides will be sold through Toro distributors once it is ready for commercial use. A distributor will have a machine and when a golf course buys the service the distributor will come to the golf course or athletic field and sample the turfgrass. When the PS6000 is ready for commercial Toro’s distributors in California and in the Carolina’s will offer the service first. Toro plans on expanding this service so that more distributors in the U.S. and worldwide will have machines and more customers will have access to the PS6000.

The pictures attached show the results of the data the PS 6000 collects. The first picture is soil moisture, the second picture is soil compaction, and the third picture is turf vigor.

Soil Moisture and Soil Compaction Data


The video attached is of a previous version of the PS 6000. The version of the PS 6000 that will be sent to distributors is equipped with a foamer so the user of the machine can see the previous passes