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Spring Showers bring Primo/Proxy

April 5, 2010

Above average temperatures swept across much of the state last week making it feel almost like summer at times. The turf seems to be responding nicely to the favorable conditions as new growth begins to take the edge off some of the scars left from the winter season.

The relatively dry weather as of late has helped speed the rise in soil temperatures and I spotted some prostrate knotweed germinating through the cracks in my driveway. Prostrate knotweed is a summer annual and usually the first annual weed to germinate in the spring. Like many weeds, knotweed thrives in compacted areas and is often found along the edges of sidewalk and cart paths.

Early spring also marks the time of year for applications of primo/proxy. Primo and proxy are both growth regulating compounds designed to slow the growth of plants. Used together in a tank mix this combination of products provides a synergistic effect to inhibit seedhead formation on poa. Inhibiting seedhead formation of poa has two main advantages. First, the flush of seedheads in the spring can be unsightly and interfere with the uniformity of the playing surface. Second, producing seedheads requires an expenditure of energy from poa which is already susceptible to many biotic and abiotic stresses. Inhibiting seedhead formation helps conserve energy within the plant (poa) which will hopefully leave it with more reserves later in the season when pressure from diseases and other stresses are higher.

The effectiveness of the primo/proxy application depends largely on proper timing. While doing my research on this topic I discovered a variety of ways in which superintendents try to properly time their applications. Some track and use growing degree days, some apply once full green up has been achieved (this is usually after the second mowing), others monitor and apply when poa is nearing the boot stage, and still others try to time their applications based on historical data of poa seedhead development. Whichever method you prefer it is important to apply before you see the seedheads. A repeat application in 14-21 days is often recommended. As always, remember to review the label before any application.

Of course the other big news this week is the start of The Masters Tournament. In case you weren’t in the mood for golf this should help. Here is a picture to wet your appetite.

Marcus Jones
Graduate Research Assistant


It’s the Start of Another Season...Almost

March 11, 2010

Winter has eased its grip on the Midwest the last 10 days or so and we have experienced significant snow melt throughout much of Iowa. Grass is even starting to peek through the snow in spots. Could this be a sign spring is right around the corner? Before we get ahead of ourselves, let’s recap the Iowa winter thus far.

Snowfall for the three mid-winter months of December, January, and February averaged 45.1 inches or 23.3 inches greater than normal. This is the greatest snow total of record for these three months (old record of 44.7 inches Dec. 1961-Feb. 1962). The snow total for the overall snow season (fall through spring) ranks 8th highest among 123 years of record with another two months of the season remaining (keep in mind that Punxsutawney Phil saw his shadow for what it’s worth). This has been the third consecutive colder than normal winter and fourth consecutive snowier than usual winter.

But, with the recent snowmelt, I was able to escape from the office for a little scouting on the golf course. With the prolonged snow cover and soil temperatures right around the freezing mark I was anticipating decent snow mold activity. The location I was scouting had been treated with a snow mold preventative but I was still able to find small breakthroughs of both gray and pink snow mold.

Most of the gray snow mold appeared in the rough areas and the damage is likely only superficial. Gray snow mold initially appears as circular patches ranging in color from light yellow to white soon after the snow melts. As the disease progresses the patches can grow and coalesce together with the leaves often becoming matted together. A reliable way to identify gray snow mold is to look for sclerotia embedded in the leaves of infected tissue. The sclerotia appear yellow to light brown soon following snow melt and eventually turn dark brown.

Pink snow mold, as its name implies, is often identified by white to pinkish mycelium that forms at the margins of the patches. The pink color is brief and often only visible during early daylight hours. I only saw two patches of pink snow mold during my outing. However, the window for pink snow mold development extends further in the spring as snow cover is not a requirement for this disease.

I also was treated to some vole damage. Voles are small rodents (4 to 6 inches) long and are mainly vegetarians. The main damage to turf is caused by their runways through the turf canopy. Vole damage is common under snow cover as they search for seeds and other vegetation.

Hopefully you’ll be greeted with healthy turf as the snow continues to melt. Let’s hope spring is just around the corner.

Marcus Jones
Graduate Research Assistant


May 2011 Weather Recap

June 6, 2011
A number of golf courses experienced severe weather during the month of May.

Although summer doesn’t officially begin until the 21st of this month, the state will experience mid-summer temperatures during the first half of this week. Dollar spot has been active for a couple weeks now and brown patch and pythium blight could make an appearance the next couple of days with the temperatures expected to be in the mid-90’s. Let’s take a quick look at the weather the state experienced in May.


Air temperatures during the month of May averaged 60 degrees which is 1.3 degrees cooler than average. The warmest day of the month occurred on May 10th as daytime air temperatures climbed above 90 degrees. The coolest day of the month occurred just four days later as temperatures plummeted to 49 degrees. Soil temperatures slowly rose throughout the month from the mid-60’s and climbed into the low 70’s towards the end of the month

After record rainfalls during the summer of 2010, it appears we could be headed down the same road again this season. May rainfall amounts totaled 5.61 inches or 1.26 inches above normal. Since May 1, central Iowa has received over 10.5 inches of rain from 35 rainfall events. During this same time period last year we had received 9.5 inches of rain from 33 rainfall events.

The month of May also saw a number of severe weather events with strong winds, thunder, and lightning. Turf areas can be a dangerous place to be during thunderstorms because they are generally open areas scattered with individual trees. A lightning bolt will take the shortest route between the cloud and the ground, which means that a golfer standing in the middle of a fairway or huddled under a tree is a prime target for a strike.


One golf course in central Iowa experienced a lightning strike on a putting green.  Remember to remind your crew about lightning safety.

The Golf Course Superintendent Association America of America (GCSAA) publishes a list of lightning safety tips. Take time to review these safety points with your crews as we enter the summer season.

•  Seek shelter at the first sign of a thunderstorm. If the course's warning system sounds, take cover.

•  If possible, get off the golf course or go to a designated lightning shelter.

•  Do not stand under a lone tree. This is where most people are injured or killed.
•  Stay away from water.

•  Stay away from your golf clubs.

•  If your shoes have metal spikes, take them off.

•  Move away from your golf cart.

•  If stranded in the open, go to a low place such as a ravine or valley.







April 30, 2014

On Nov. 16, 2013 I wrote a blog about the fact that tall fescue seemed to be going off color earlier than usual in the fall of 2013.  It seemed to be turning brown weeks ahead of the other cool-season species.

This spring, it seems to be greening up much later than usual.  We had a hard winter in Ames and tall fescue is more susceptible to cold temperature damage than grasses like Kentucky bluegrass and creeping bentgrass.  However, the greenup of tall fescue appears to be surprisingly late.  The pictures below were taken on April 25, 2014.  The demonstrate the very slow progress of greenup on tall fescue in our region.

The first picture is from the perennial ryegrass National Turfgrass Evaluation Program (NTEP) trial at the Iowa State turfgrass research area.  The left is a tall fescue area surrounding the trial and the right is a series of 5 X 5 ft perennial ryegrass cultivar plantings.  As I have covered in earlier blogs, perennial ryegrass also showed damage from the winter.  Even the ryegrass is greening up well ahead of the tall fescue.  The dormant plot is Lynn perennial ryegrass.  There were considerable differences in greenup among the perennial ryes this spring.  I have data that I will report later.

The next two  pictures are the tall fescue NTEP trial.  The green strip is a perennial ryegrass planted between the replications.  The tall fescues have still not greened up as of today, April 30.  We will be collecting data on tall fescue greenup as it begins.

The next two pictures are of a tall fescue sports field that I established at a local church site (the Plex) four years ago.  The green area on the left in the upper picture and the right in the lower picture is a Kentucky bluegrass/perennial ryegrass turf that is emerging from dormancy.  The right is the tall fescue field that is still brown on April 25,

I am wondering if others in the Midwest are seeing this same slow greenup of tall fescue.  Send me some pictures if you are seeing this.



April 3, 2014

 Winter damage at turf research (prior year)

 Desiccation on bentgrass (prior year)

Winter damage to turf can occur from a variety of causes.  These include diseases such as snow mold, ice cover, traffic, frost heaving, desiccation, and direct low temperature damage.  In recent years, desiccation due to mild conditions, lack of snow cover and drying winds late in the winter have been the biggest reason for winter damage in Iowa (see my blog on this site from January 2, 2012).  Snow mold is sometimes a problem (see blogs from March 11, 2010, Sept. 10, 2010, Nov. 27, 2012 and Dec 8, 2012).  The biggest concern this spring, however,  is likely to be direct low temperature damage.

This past winter has been one of the coldest in recent memory for most of us in the Midwest.  As Ryan mentioned in his last blog, the average temperature over the past 3 months was 14.7 degrees F as compared to a normal average of 22.1 F.  We also hit some very low temperatures during the last 3 months, with low temperatures on some days dropping below -20 F.  Records in Ames show that this winter was the ninth coldest in the last 141 years. The question as to how much winter damage we will see as the turf emerges from dormancy depends on the species grown on the site and on a series of complicated, interacting conditions that occurred during the winter.

Kentucky bluegrass (Poa pratensis) and creepging bentgrass (Agrostis stolonifera) tend to be quite tolerant of cold temperatures.  The fine fescues as well have proven to be quite tolerant in my experience.  Perennial ryegrass (Lolium perenne), tall fescue (Festuca arundinacea), and Annual bluegrass (Poa annua) are more likely to be damaged by low temperature.  The warm-season grasses are generally more susceptible to cold temperature damage.  Bermudagrass (Cynodon spp) is easily damaged, whereas Zoysiagrass (Zoysia japonica) and buffalograss (Buchloe dactyloides) are more tolerant.  It will be on the perennial rye, tall fescue, and annual bluegrass that I expect the most damage as the grass emerges from dormancy in this area.  Creeping bentgrass is very susceptible to winter desiccation, but the continual snow cover that we have had in most regions of the Midwest should prevent this from being a major problem this year.

An even more important determining factor in direct low temperature kill is the condition of the grass going into the winter and the conditions that occur in the localized area during the winter.  Seedling ryegrass and seedling tall fescue that were established late in the fall are particularly susceptible to cold temperature damage.  It is not unusual to loose late seedings of these species in years with less severe winters that occurred this year. Mature stands of these species survive cold temperatures much better if they harden off properly before extremely cold temperatures occur.  Snow cover during the winter tends to be a good thing, and I rarely see damage in cold winters when snow lasts most of the winter as it did this year. 

If there has been intermittent melting, allowing water to settle in low areas, followed by a hard freeze, damage is more likely to occur.  This is particularly true of perennial ryegrass and annual bluegrass damage.  I have observed this type of damage a number of times over the years and I expect to see some of it this spring.

Damage to annual bluegrass is hard to predict.  This species is more sensitive to direct low temperature kill than is either Kentucky bluegrass or creeping bentgrass.  However I have seen years where I expected to see a lot of annual bluegrass damage and didn’t.  There have also been years when I didn’t expect damage and a lot of it occurred.  Again, it is a series of other factors that determine annual bluegrass damage.  These include the condition of the grass going into the dormancy and the combination of weather conditions that develop during the winter.  As cold as it was this winter, I am anticipating quite a bit of damage.  I am getting early indications from the Chicago that quite a bit of damage has occurred on greens and fairways where annual bluegrass is the primary species.  I’ll keep you informed on that as the spring progresses.  Winter damage to annual bluegrass is often quite localized due to variations in winter conditions.  Here in central Iowa, the annual bluegrass seems to be emerging from dormancy in good shape.

In the last two years, I have done a number of blogs on bermudagrass showing up in Iowa turf areas (Aug. 2, 2012, Sept 18, 2013, July 29, 2013, and June 17, 2013).  Another warm-season grass that has become a problem because of the series of mild winters in recent years is Windmill grass  (Chloris verticullata) (Sept. 19, 2013, July 3, 2012, Aug. 6, 2012).  Neither of these species was a problem up to about 5 years ago.  Both species are quite sensitive to cold temperatures.  It will be interesting to see if they survive this severe winter.  Windmill grass is a perennial, but it is also a very good seed producer.  I suspect that this grass is here to stay, even if a lot of the existing plants died during the winter because of the amount of seed in the soil.

Windmill grass in lawn.


Windmill grass seedhead.

Bermudagrass on Iowa State campus in the summer of 2013.

Let me know what you are seeing as the season progresses.  I would appreciate any pictures that might be of interest to others in the industry.



December 3, 2013

Here is some more information on the advanced turf class that will be offered this coming spring.  Let me know if any of you have any questions.

It is available for undergraduate credit and graduate credit for those of you working on an MS degree.



We are pleased that you will be teaching HORT 451–using Blackboard Learn for the spring 2014 semester. Dates that we have listed for your course are: Monday, January 13, 2014 to Friday, May 9, 2014. Course website: Please review and let me know of any corrections that need to be made by Friday, December 6th, 2013.   


The book and course packet information listed on the Course Initiation Form was:

Fundamentals of Turfgrass Management & Mathematics of Turfgrass Maintenance

Students may order their textbook through the Iowa State University Book Store at http://www.isubookstore.comOr they may also use other online resources to order their textbook just make sure they understand which edition or ISBN number they should be looking for.

Notes from Brenton Center: If you have online course charges, please contact Amy Pilcher for information about how to report those expenses:

**I am attaching the letter that will be sent out to all students enrolled in your distance education class. Please review the attached letter and get back to me with corrections before Friday, December 6th, 2013 or the letter will be sent out as is.  


Unless specifically directed otherwise please have your students register in the following manner:

New students to Iowa State University have to apply for admission as a non-degree seeking student: is a $40 application fee)

Returning ISU students can register either through Access Plus or by calling the Office of the Registrar at (515) 294-1889 during regular business hours, Monday-Friday, 8am-4pm (CST). 

To drop or withdraw from a course, students must use AccessPlus or contact the AgOnline Coordinator at  Failure to attend a class does not constitute withdrawal and a student will be billed for the full tuition.

Electronic class lists are available to instructors on the web through ACCESSPLUS.

All students are issued an ISU ID number. This number authorizes students to use the ISU e-library facilities, Access Plus, and to establish an ISU NET ID,  Students in classes using Blackboard, need an ISU NET ID to log-on to the system.

Best wishes for a great semester!  If there is anything more that we can do to make your off-campus teaching more rewarding for you and your students, please let me or the other Brenton Center staff know.  Thanks!

Amy Pilcher

Departmental Fiscal Officer

Brenton Center for Agricultural Instruction & Technology Transfer

College of Agriculture and Life Sciences Distance and Online Education

Global Food Security Consortium

0004 Curtiss Hall

Iowa State University

Ames, Iowa 50011-1050

Office:  515-294-1862

FAX:  515-294-1924