Friday, July 31, 2009

The Bizarro Weather

The state experienced below normal temperatures during the month of June and we just concluded a very mild July! The weather this year has been downright bizarre and reminds me of the Seinfeld episode where Elaine replaces her normal group of Jerry, George, and Kramer for her Bizarro friends Kevin, Gene, and Feldman who possess opposite, more attractive characteristics. A generous, agreeable mailman named Vargas even surfaces as a replacement to Jerry’s arch nemesis Newman. The weather during July seemed to follow this trend. We had September temperatures in July.

I was curious just how bizarre the weather was so I looked up the historical weather data in Ames for the month of July going back to the year 2000. The average high temperature for the month was 78.7 degrees. This ranks as the coolest average high temperature in the last decade. Similarly, the average low temperature was 59.3 degrees which also ranks as the lowest in the last decade. (In case you were wondering, the warmest July in the last decade was in 2002. That year the average high temperature was 86.3 degrees and the average low temperature was 65.6 degrees).

Of course, the benefit of the cool temperatures has been low disease pressure compared to what we normally experience this time of year. Just don't forget to grab a light jacket on your way out the door this morning.
Marcus Jones
Graduate Research Assistant

Monday, July 27, 2009

Interseeding Study at Hyperion Field Club

The research for my PhD program focuses on interseeding. Specifically, I am interested in developing methods which would allow a turf manager to convert to new, improved varieties without taking an area out of play. Interseeding is such an interesting topic because it has been an area of great debate. Most researchers contend interseeding is not possible while some turf managers insist interseeding is an effective way to add turf to already established areas.

One of my interseeding studies is located on a practice putting green at Hyperion Field Club. Below are the details of the study and why I think this project has a chance to be successful.

Presence of Poa annua – The practice green where the study is located has between 50-60% poa. So why would this help the interseeding process? The success of establishing new seedlings in existing turf is closely tied to plant competition. Trying to establish a cool-season species in established cool-season turf is difficult because they both share the same growth cycle. This is also the reason why overseeding in the southern U.S. is so successful. Cool-season grasses seeded into warm-season turf works quite well because they have different growth cycles. In our situation, even though poa is a cool-season species it is a winter annual. Winter annuals germinate in the fall persist through the winter and spring before ending their lifecycle during the summer months.

Products that harm Poa annua – There are perennial-type poa’s as well, but they are generally more susceptible to summer stresses compared to creeping bentgrass. Our study is utilizing Velocity and Trimmitt, both products that harm poa more than bentgrass. Velocity applications started June 4 and were applied at 2 oz/A every 14 days for a total of 4 applications. Trimmitt applications also started June 4 and are being applied at 6 oz/A every 14 days. A total of 8 applications of Trimmitt will be made.

Establishing a creeping bentgrass seedbank – There are many plants that have been classified as “invasive” species. A shared trait of these plants is their ability to produce large volumes of seed and establish a seed bank. This is one reason why poa is so successful at colonizing established putting greens. I am borrowing this concept and attempting to establish a seedbank of creeping bentgrass. Bentgrass seed is being spiked into the green every 14 days at a rate of 1.5 lbs/1000 ft2.

Accurate, non-disruptive spiker/seeder – The attraction of converting through interseeding is that play can continue during the conversion and revenue is not lost. Therefore, the process of placing the seed into the putting green must be non-disruptive. I’m using a walk-behind Maredo spiker/seeder to seed into the putting green. The company that manufactures this machine also makes floating heads that mount on a triplex unit. This machine accurately meters creeping bentgrass seed into many small holes. There is minimal disruption and play can follow directly behind the machine.

Choosing aggressive varieties of bentgrass – Because the Maredo creates minimal disruption, the opportunity for new seedlings to germinate and establish before the holes close is small. Therefore, it is crucial that the bentgrass species selected for the interseeding process possess high vigor. I recently conducted a germination experiment with many of the new, improved bentgrass cultivars. The results of this study showed that the cultivars T1, Penn A-1, Penn A-4, Crystal Bluelinks, Pennlinks II, Independence and Declaration germinated significantly faster compared to Penncross. Based upon these results, I am using Penn A-4 as an interseeding species.

Interseeding timing and seeding rate – In addition to spiking seed every two weeks to half of each plot, the entire study is interseeded three times a year: May 28, July, 30, and September 17. The May 28 and September 17 calendar dates correspond with spring and fall aerification and seed is sown at 1.5 lbs/1000 ft2. Research has shown that interseeding into poa is most effective when performed mid-summer. The July 30 calendar date is designed to introduce seed into the putting surface when poa is at a competitive disadvantage due to summer stresses in addition to the Velocity or Trimmitt. The July 30 seeding will be sown at 3.0 lbs/1000 ft2. The higher than normal seeding rates are designed to account for the high mortality rates expected from traffic and plant competition.

I started the study this spring and it’s scheduled to run for two years. My first round of data will be collected this fall and I will be presenting the results at the Iowa Turfgrass Conference. Any comments or questions regarding this work can be directed to

Marcus Jones
Graduate Research Assistant

Friday, July 24, 2009

Coming Soon to the Iowa Turf Market

MaxTerra and GeMax, both companies of MaxYield a cooperative in the state of Iowa, are in development of a new pelletized organic fertilizer with an analysis of 4-2-2. I have a limited supply of this product, but would furnish up to 200 pounds to several different courses for your insight and research on how the product can help you with some issues on your courses.

Larry Arndt
Marketing Director & New Business Development
Cell Phone 712-320-7448

Wednesday, July 22, 2009


Congratulations to Rick Tegtmeier. This is Windmillgrass (Chloris verticillata).
When the seed head separates from the plant in the fall, it rolls like a tumbleweed and spreads its seed over the landscape. It has been present in central Iowa for only a few years. It is a warm season that is damaged by cold winters and was generally found in Missouri and south until recently. It is often seen along the curbs of streets and other compacted areas.


This is a relatively new arrival in central and northern Iowa. It is a perennial warm-season grass that forms an expanded panicle seed head late in the summer. It is generally found in dryer compacted areas. Any guesses?


Monday, July 20, 2009

Commenting on a Post and Other Blog Tips

We have received a few questions regarding how to leave a comment for a post. Anyone can leave a comment, but there are a couple of different ways to go about doing so. At the bottom of each post, there is information regarding who posted the article, the date and time the article was posted, and if there are any comments on the post. (The envelope icon allows you to forward a post to someone using e-mail).

To leave a comment, just click on “0 comments” directly below the post. This will open a new screen where you type in your comment and some other information. Type your comment in the box provided. A “word verification” is located below the comment box. You will need to retype the word verification that appears on the screen. Next, you need to select an identity. The first two options require that you have a Google Account or an account already established with one of five Open ID services (Open ID, LiveJournal, WordPress, etc…). If you have one of these accounts and want to leave a comment, check the appropriate box and follow the directions.

If you don’t have one of those accounts, you will need to check “Name/URL” and type in your name (you can leave the “URL” box blank). If you wish to leave an anonymous comment, check the anonymous box. You can preview your comment by clicking on the “Preview Button”. This allows you to see your comment and make any last changes (if you need to make changes click on “edit comment” in the lower left hand corner of the comment box). Otherwise, click on “Publish Your Comment” and that’s it, you just commented on a post.

Another topic I’ll discuss quickly is how to subscribe to the blog. You may have noticed the “Subscribe via email” gadget along the right hand column. By subscribing to the blog, whenever a new post is added it will automatically be sent to the e-mail address you provide. This is an easy way to receive content without ever actually visiting the blog.

Marcus Jones
Graduate Research Assistant

Sunday, July 19, 2009

Lightning on the golf course

Here is a post from Ryan Adams, an ISU student on a 6 month internship at Pinehurst this summer and fall. It shows what lightning can do.

Dr. Christians
Just to give a little explanation of what happened. The lightning actually struck about 5 ft from the irrigation head and proceeded into the ground, fried the satellite box and then came back through the wires and blew the irrigation head out of the ground. Crazy, especially considering we still haven't found the nozzle or top cover to the irrigation head.

Ryan Adams
Turf and Marketing Student
Iowa State University
Ames, IA 50011

Friday, July 17, 2009

The following is a post from Luke Dant of Syngenta products about a disease called Waitea patch, caused by Waitea circinata var. circinata. The picture above is from Ron Calhoun at Michigan State. It shows the disease attacking Poa annua, but stopping when it gets to the bent.


Luke, thanks for the post.

Recently in industry magazines, or via conferences you may have heard of a new disease referred to as Brown Ring Patch or Waitea patch. In my travels, I have only seen the disease twice, both times in MN, once on bentgrass putting greens, once on Poa annua greens.

In both cases that I have seen, it appeared after 3-4 days of highs reaching 75-85 degrees with high humidity (65+ degree dew points).

In the particular case pictured here, it occurred on Poa annua and the rings were identified on Tuesday, June 23. An application of Headway at 3oz/1000 sq. ft was applied on Wednesday, June 24 and by Friday, June 26 (the date the I took the picture) most of the rings had dissipated and would go unnoticed by the average golfer. In this instance, there was no turf loss and the rings have not reappeared.

I have included two links as references:

Luke Dant
Syngenta Professional Products

Thursday, July 16, 2009

FRAC Mode of Action Symbols

You may have noticed a new designation on some of your fungicide, herbicide, and insecticide labels. The designation is located in the upper right or left hand corner of the label cover (Picture above). The numbering system was established by the Fungicide Resistance Action Committee (FRAC). The purpose of FRAC is to help prevent fungicide resistance and prolong the effectiveness of “at risk” products. A key to accomplishing this goal is understanding a products mode of action. Mode of action refers to the biochemical mechanism(s) by which the product controls a pest.

Some products are site specific in their mode of action whereas others affect multiple sites. In general, contact fungicides have a very broad base of activity and use of these products will very rarely result in resistance because they possess multiple modes of action ((the one exception is fludioxanil (Medallion)). The chance of resistance is much greater with the systemic fungicides because these products only affect a single biochemical pathway (single mode of action). One of the best known cases is the resistance of dollar spot to the benzimidazole fungicides.

All active ingredients from all chemical manufacturers have now been assigned a “group number” based on their mode of action. Some fungicides are labeled "M," which means that the fungicide acts upon multiple sites and the risk of resistance is low. The numbering system allows for a quick comparison of modes of action between two or more different products (Picture to the right). For a complete list of FRAC codes see Alternating between products that have different modes of action will help prevent resistance from developing.

Mode of action symbols should never be used alone when making resistance management decisions. Other guidelines to help prevent or delay resistance include:

- Use good cultural practices that will limit disease activity

- Choose resistant turfgrass cultivars

- Properly identify the pest

- Decide if it warrants treatments based upon established thresholds

- Apply according to label direction through properly calibrated equipment

- Know the characteristics of the product including the active ingredient and if repeated use is likely to lead to resistance

- Mix or alternate between products with single modes of action and those which posses multiple modes of action

Marcus Jones
Graduate Research Assistant

Wednesday, July 15, 2009

We Will Miss You

Derek Harmon, 27, passed away July 10, 2009 at his home in Ames. He worked on the maintenance staff at Veenker Memorial Golf Course. Derek was leading the Audubon Certification program and was involved in all phases of the reconstruction project this past season. Derek was a Senior at Iowa State University and a great friend to many. We will miss you Derek and always remember how you touched so many lives.

Thoughts on your life, and the enjoyment I received from the short relationship.

-Seeing you respond to the many challenges you faced in life…too many
-Remembering the smile on your face on Thursday, July 9th when to our surprise almost 85 percent of the small trees we planted this spring were surviving
-The satisfaction of having the golf course ready for another Iowa Masters Tournament
-The personal relationship you had with our land and natural resources
-The growing in of our native areas to reduce pesticide usage and to improve the water runoff into our environment
-Proper placement of the bluebird houses, the joy you had when almost 40 new bluebirds hatched at Veenker and now are part of the Veenker habitat
-Informational talks we had about the wildlife habitat both at Veenker and your favorite hunting spots, and how we could help protect this precious land and resource
-Developing the plans for new Veenker and its environment
-Your hunting and fishing adventures
-Boating on Veenker to help wash off greens after the flooding
-The garden you and your Dad planted this spring, and how great the potatoes tasted
-The mushroom hunts and the secret spots
-Listening to tales about the Chicago Cubs, Bulls, & Bears
-Seeing your joy when you purchased your golf season pass (Pass number 1) and promptly went out and shot 39…WOW
-Always drinking the Cyclone Kool-Aid seeing that next great victory
-Your displeasure with fellow staff members when they may have taken a shortcut or not completed a task to the best of their abilities
-The renovation project we all went through, and the joy of successes, and hard fall’s with some of our failures
-I would go on but tears keep me from wanting to remember all the great times

Thanks for all the memories.

John Newton
Golf Course Superintendent
Veenker Memorial Golf Course

Tuesday, July 14, 2009


As a follow up to Don Lewis' post a few days ago on Japanese Beetles, they seem to be active in large numbers now (July 14, 2009). I found hundreds of them on my Linden tree last night. They are also hitting some of the shrubs. Their arrival in central Iowa is fairly recent. It has only been the last four years that I have seen them in significant numbers.

Linden trees (Tilia spp) are a favorite of the Japanes Beetle. The picture below shows a Linden on Barrington CC in Chicago in 2008. The insects start feeding on the top of the tree and move down. They can defoliate a Linden if there are enough insects present and the tree should be treated with insecticide if the problem is bad enough.

The second picture show a Japanese Beetle on the left and a Masked Chafer on the right. I took this picture on Iowa State campus. Both species lay eggs in the turf that will hatch into larvae that damage the root system later in the summer. Fortunately, the Masked Chafer adult does not do significant damage to landscape plants.

Monday, July 13, 2009

Trouble Spot at Des Moines Golf

This is an area on our #4 green south. Over the last 3 seasons we have seen the same symptoms in the same area each year. The area gets wilted very easily and the roots are dysfunctional. We thought it was take all patch. This is on a Penn A-4 green. This spring we treated the green with 2 applications of Heritage. It is not as bad as in prior years but it was showing up again in the hot weather.

We sent a sample off and it did test back as take all patch. Recommendation from the lab was to solid tine aerify, keep the nitrogen level up and to do multiple fungicide applications in the late fall and early spring. Also to incorporate Manganese sulfate in our spray next spring. It does look better this week.

Rick Tegtmeier

Twospotted spider mites on underside of leaf

Summer showers bring aphids & mites

Summer thunderstorms bring warm moisture from the gulf, but carry pests that normally do not over winter in the northern climates. Shrubs and trees may be showing signs of drought, but it could actually be aphids or mites sucking the "juice" out of your landscape. Up Star Gold (bifenthrin) or Flora-mek are two good miticides.

Jerry Deziel
Sales Representative
Reinders Inc.

Saturday, July 11, 2009


Nick, thought I would send you an update of what's been going on out at the farm in the event you wanted to post something on the blog site.We just finished seeding the new T-1 bentgrass area (July 8)(picture 2). There was approximately 8,000 square feet seeded to T-1 with the surrounding areas seeded to Front Page Kentucky bluegrass. Before the seeding was done 1lb P/1000 sq. ft. was applied using a 11-52-0 fertilizer and 0.5lb K/1000 sq. ft. was applied using potash with an analysis of 0-0-45. Feel free to swing by the research station to view the grow-in progress.

There is also a lot of brown patch present on some of our bentgrass, tall fescue, and bluegrass areas. We have also seen a remarkable amount of red thread, on both tall fescue and perennial rye, that has continued to hang on into early July. Also, last week, on July 2, the second application of herbicides was put out on the crabgrass control study.

Final data on the Tenacity (mesotrione) phytotoxicity study (picture 1) will be taken soon and the third application of fertilizer for the Micropel greens grade fertilizer study is set to go out early next week.The new bentgrass research area at the research station recently recieved its first application of fungicides (Daconil Ultrex (chlorothalonil) and Emerald (boscalid)) on Tuesday June 28.

We are now closely monitoring the amount of dollar spot that has infested the plots to determine the approximate timing of a second application of fungicide.We have also completed replacing close to half of the irrigation heads in the Rainbird section of the research station.
If anyone is interested in seeing any of the research going on at the horticulture research station, feel free to stop by and don't forget that the 2009 All Horticultural Field Day is August 6th.

Nick Dunlap
GCSAA Campus Representative
Turfgrass Management
Iowa State University

Friday, July 10, 2009

Hard Year in Kansas City

Throughout the 2009 season, we have experienced lots of extremes, both in weather and disease. The year started out extremely warm in January through March, with soil temps reaching close to 60 degrees. This rise in temps fell off soon after aerification and remained throughout April and into May. Since then temperatures have soared and so has disease. There have been many cases and outbreaks of Pythium, Zeae, dollar spot, brown patch and red thread. The heaviest cases coming from June 15th through the 29th when we had days in the upper 90's and lows in the mid to upper 70's (Picture on right shows extensive tracking lines from golf carts that had heavy mycelium growth in the morning and were like this by night fall the same day. They were sprayed later that morning with mancozeb and banol and no more activity was seen).

With the heat came a great deal of humidity and disease. Soil temps reached over 98 degrees and stayed there for a good 10+ days damaging many roots and leaving the grasses susceptible to pythium and root rot. Some practices used both at my course (Royal Meadows) and several other courses in the area were the use of a pull-behind Planet Aire. This machine slices tear-drop size slits in the green with minimal surface damage but can go 6 inches deep, done in the same time as a greens mowing with golfers barely noticing. It allowed us to manage our root-zone and keep the damaging water and moisture under control. Many superintendents use solid tines or spikers, but the speed and efficiency of the Planet Aire is second to none, a highly recommended machine to add to your collection.

As we have moved into the typical hot and disease prone months of July and August, the courses with cool-season fairways will have some interesting chemical and fertilizer purchases. With revenues down and temperatures up many course managers need to slash budgets, even when we as superintendents need to increase our spending for these difficult months. Some successful practices that I have seen on Bent/Poa fairways in Kansas City are as follows:

- Calibration of equipment, correct nozzles (AIC 11010vs) and proper rates (50 gal/acre for fairways)

- Use of generic pesticides when applicable (typically have less time between sprays, weather and products not sticking to plants as well, but huge cost savings!) If you would like a list of products that we have field tested and found as the best generics email me at

- Stress fighters and Phosphites (control of pythium by building larger cell walls and improving plant health)

- Spot Spraying in low areas for Pythium and other water prone diseases (pre disease is best) instead of broad applications that are extremely expensive

- The use of contacts and systemics, with rotations of different modes of actions, chemistries and formulations at different times of the year

- Growth Regulators, both for seed head suppression in the Spring and restricted/controlled growth in certain times of the year

- Above all is always being aware of your golf course, knowing each and every trouble spot, watching water usages, remember a dry golf course is a lot better than seeing a solid cotton field of disease

If you have any questions concerning your spray rig set-up, fungicide timing, application rates or even our fungicide program at Royal Meadows please let me know. It is a tough world out there with all of us constantly balancing our budgets and beauty of our golf courses.

Mark Newton
General Manager & Course Superintendent
Royal Meadows Golf Course

Thursday, July 9, 2009


I found this rather unusual weed in a lawn on July 9, 2009 (the picture on the bottom). I also found the same species on campus last year (picture on the top). It is unusual for this area. Post your guess as to what it is in the comment section. The answer will follow in a couple of days.

Congratulations to Nick Dunlap for figuring this one out.
It is Yellow Rocket (Barbaria vulgaris), part of the mustard family. It was quite common in Ohio when I was there many years ago, but I just began seeing it three years ago in Iowa. Since then, I have seen a number of them in central Iowa turf. It is not hard to control, similar to dandelion.

Wednesday, July 8, 2009

Anthracnose basal rot

The multitude of summer stresses appears to be in full swing. This morning on my way to mow some of my research plots I spotted a black cutworm, masked chafer, and some brown patch. I have also heard some grumblings about anthracnose. Anthracnose can be one of the most difficult diseases to control, especially after symptoms develop. As with all diseases and insects, the first step in management is proper identification so you know what you are dealing with.

On a mixed stand of annual bluegrass/creeping bentgrass the symptoms of anthracnose often appear in a patch-like arrangement (picture on right). This is because the anthracnose will usually only infect one of the species, although in rare cases it can attack both. Infected poa will display a yellowish/bronze appearance while infected bentgrass appears droughty. The way I prefer to diagnose anthracnose is with a 30X macroscope. You can usually see the fruiting bodies embedded into the leaves and sheathes (picture below). However, be careful not to misdiagnose a recent application of organic fertilizer for the fruiting bodies of anthracnose. (I have made that mistake before).

I was always told the best way to manage anthracnose is through a combination of preventative fungicide applications and cultural practices that reduce stress on the plant. Fungicide applications made after the symptoms have developed are usually not very effective. There have been reports of disease resistance developing from persistent use of the MBC, DMI and QoI fungicides (Methyl Benzimidazole Carbamates, DeMethylation Inhibitors, and Quinone outside inhibitor). Avoid sequential applications of these products and tank mix with a contact fungicide to help prevent fungicide resistance from developing. Anthracnose can overwinter in the crown and roots of infected plants and a “clean up” fungicide application shortly before winter may also help in preventing the severity of the disease the following year. If anthracnose still occurs, recommendations usually include light fertilizer applications and the stoppage of any plant growth regulators.
Marcus Jones
Graduate Research Assistant

Tuesday, July 7, 2009

2009 Turfgrass Research Report Is Now Available

The 2009 Turfgrass Reseaerch Report is now available at

You can also get full text of all reports back to 1997 on Turfgrass Central located at that same URL.

Don't forget the All Horticulture Field Day Aug. 6, 2009.

Nick Christians

Monday, July 6, 2009



For the last twenty years, we have maintained National Turfgrass Evaluation Program (NTEP) creeping bentgrass studies at Iowa State University. These were coordinated by NTEP, based out of Beltsville, MD. Like many other entities in this economic environment, NTEP has come on hard times and has suspended these projects at most of the Midwestern universities last year.

In response, turf researches in this region have banded together and formed our own trials. These include both fairway height and green height studies. They were seeded in the fall of 2008. The coordinator of these tests is Qi Zhang of North Dakota State University. She obtained the seed from the seed companies and distributed it to the cooperating universities. She will also coordinate data collection.

The varieties in the trials are listed in Table 1.

Table 1. Cultivars being tested at Iowa State University in the green height and fairway height creeping bentgrass trials.

Green Height
1. L-93
2. T-1
3. Alpha
4. Putter
5. Southshore
6. Kingpin
7. Crenshaw
8. Imperial
9. Century
10. Penncross
11. A-4
12. Crystal bluelinks
13. Penn A-1
14. Penn G-6
15. 007
16. MacKenzie
17. Tyee
18. SR 1150
19. Memorial
20. Independence
21. Declaration
22. LS - 44
23. Bengal
24. Alister

Fairway Height:
1 . L-93
2. T-1
3. Alpha
4. Putter
5. Southshore
6. Kingpin
7. Crenshaw
8. Imperial
9. Century
10. Penncross
11. A-4
12. Crystal bluelinks
13. Alister
14. Pennlinks II
15. 007
16. MacKenzie
17. Tyee
18. SR 1150
19. Memorial
20. Independence
21. Declaration
22. LS - 44
23. Bengal
24. Penn G-6

Both the green height and fairway height studies will have an additional test imposed on them. Each plot will be split in half. One side will receive no fungicides and the other side will receive Emerald and Daconil to be applied when dollar spot infestation reaches 5%.

The field day at the Horticulture Research Station will be August 6, 2009. We will be looking at these studies and several others of interest to the turfgrass industry at that time. We are doing something different with field day this year. It will include all areas of horticulture that have projects at the horticulture research station. We will have on-site registration only for this event. The cost, with lunch, will be $20 per person. You will have a chance to see turf research, but can also attend events on trees, shrubs, vegetable and fruit production, gardening and other areas of horticulture. More information will follow by e-mail in a few weeks, or you can contact Nick Christians ( phone 515-294-0036) for additional details.

Above is a picture taken on 7/6/09. This is the first dollar spot differences that I have seen between treated and untreated sections of the plot.

Friday, July 3, 2009


A recurring problem on Midwestern golf courses is a loss of Poa annua in the collar area and approaches during summer stress periods. The Poa generally looks good in the fall and spring, but dies in July or early August. A possible solution to this problem, is convert the collar and approach areas to perennial ryegrass and then use Prograss (ethofumesate) to control the Poa.

Prograss doesn’t work well in bluegrass or bentgrass turf, but it is very effective in perennial ryegrass because of the tolerance of this species to this herbicide even in the seedling stage. If you have access to the turfgrass information service web site, you can get an article that I wrote on a similar subject a few years ago. Its title is “FAIRWAY CONVERSION: THE ANNUAL BLUEGRASS TO RYE TO BENT APPROACH”. It was published in Golf Course Mgt. August 1990.

The picture above is from Terrace Hills Golf Course in Altoona. Superintendent Bill Barker used this approach to solve the loss of Poa in summer. The picture was taken in late summer when most of the Poa had died out. The perennial rye is doing fine. The narrow strip around the green is where he stayed away from the green surface with the sprayer when he was applying the Prograss. As can be seen, the Poa survived in the untreated strip and died during the stress period.

I would like some feedback from those who have had some experience with this procedure (positive and negative) and from those with questions. Just use the comment section below and post your comments.

Nick Christians

Thursday, July 2, 2009

Japanese Beetle Update

The first reports of Japanese beetles have been received. Bob Dodds the Lee County Extension Director and incoming Region 20* Extension Education Director reported a few Japanese beetles in his orchard on June 22. Duane Gissel, Extension Horticulturist in Scott County reported the first sighting of JB on the morning of June 29, and by that afternoon was flooded with calls from clients. Most reports were from areas where JB has more recently arrived and residents are not familiar with the pest (Blue Grass and the western parts of Davenport, and Eldridge).

The current, known distribution of JB in Iowa includes 38 counties (picture on right). The first issue with Japanese beetles will be the feeding by the adults on foliage, flowers and fruit. Linden tree leaves are one of the favorite foods of the adult beetles. See

Defoliation is usually not fatal to otherwise healthy trees. We usually don't know what stresses are occurring so there is no easy way to predict the tree's response to defoliation. Treating grubs in the turfgrass does not impact the beetle populations on the tree the following year. There are way more places for grubs to develop in the soil than can be treated, and the relatively small amount of the total population that is treated does not impact the overall population.

In addition to spraying trees two or more times with insecticide for contact control of Japanese beetles, many landscape maintenance workers are reporting good success using systemic insecticides, applied to the soil around the base of the tree at the start of the beetle appearance. The insecticide moves upward and into the leaves and kills the beetles as they feed. Some injury still occurs but less than if the tree is not treated. See

(*NOTE: For more information on the ISU Extension Restructuring see our web site at

Donald Lewis
Extension Entomologist
104 Insectary Building
Iowa State University
Ames IA 50011 USA

Wednesday, July 1, 2009

What type of nozzles do you use?

Hot temperatures and high humidity swept through much of the state last week. Undoubtedly, many of you were busy applying plant protectants at your facility. A great deal of thought is usually given to product selection, application rate and timing, spray volume, etc., but how much thought is given to the type of nozzles on your sprayer?

Spray nozzles affect the amount of product applied to an area, uniformity, and the potential for drift. Most nozzles operate between 30 and 60 psi and as pressure increases droplet size decreases and the potential for drift is greater. The four nozzle types most commonly used for turf applications are: flat-fan, air-induction, pre-orifice flat-fan, and flood-type nozzles.

Flat-fan (A): These are the most common nozzles used for turf applications and produce a fine to medium droplet. Spray coverage is excellent but drift may be a concern.

Air-induction (B): These nozzles produce a medium to coarse droplet which shatters upon contact with the leaf blade to provide better coverage. The potential for drift is reduced with air-induction nozzles.

Pre-orifice flat-fan (C): These nozzles reduce pressure internally and produce a larger droplet than the traditional flat-fan nozzles. As a result, the potential for drift is greatly reduced.

Flood-type nozzles (D & E): These nozzles produce extremely coarse droplets and drift is greatly reduced. These nozzles are great for applying products that must reach the soil but are not recommended if good coverage of the leaf blade is required.

Critical factors to consider when selecting nozzles are droplet size, chemical mode of action, and the location of the targeted pathogen. Contact mode of action products require thorough coverage of the leaf blade in order to be effective. These types of products should be applied through a nozzle which produces a fine to medium droplet size. In contrast, products that target a pest in the soil can be applied through nozzles which produce much coarser droplets.

The goal when selecting nozzles should be to achieve good coverage while minimizing drift. Products generally fail to provide adequate control when spray volumes are too low and droplet size is too coarse to provide adequate coverage. Research has shown that air-induction nozzles provide equivalent control compared to flat-fan nozzles while reducing the potential for drift.

More detailed information about nozzle selection may be viewed at:
Marcus Jones
Graduate Research Assistant