Dollar Spot Disease 2010, Tim Sibicky, CDGA Turfgrass Research Manager

Warmer temperatures this week have provided suitable environmental conditions for dollar spot (Sclerotinia homoeoecarpa) development on fairways. We are now beginning to see a lateseason surge in damage as we enter the autumn months. Thinking back to the beginning of the 2010 season, we set out to investigate the effectiveness of early season dollar spot programs and if you look (Figure 1) we are able to see the progression of the disease at a variety of different locations surrounding Chicago. So I ask, was it worth it to spray early in April-May? At our locations for this year’s Biorational study, ranging from North Shore Country Club in Glenview, IL Coyote Run Golf Course in Flossmor, IL and Briar Ridge CC in northwest Indiana, it is evident that the disease failed to take off until the middle of summer.

As an additional note: each of our locations vary in turfgrass composition with Coyote Run having a blend of Southshore and L93, Briar Ridge CC with Penncross and North Shore CC having a mix of creeping bentgrass and Poa annua. We tested seven treatments, Rhapsody 10 fl oz, Ecoguard 20 fl oz, Dew Cure 4.0 fl oz, Urea 0.15 lbs, Daconil 3.2 oz, Daconil 3.2 oz curative (as needed using 5% damage threshold).

Treatments are being applied at 14 day intervals at label rates and the plots at all locations are scouted weekly. If disease infection centers exceed an average of 5% area affected a curative application of 3.2 oz of Daconil is applied over the biorational treatment. We are able to understand the effectiveness of the different treatments by comparing visual quality, percentage of disease, and number of curative fungicide applications. Our goal is to reduce fungicide use and maintain turfgrass quality at levels required for fairways.

Results (Table 1). At Coyote Run GC, we have been able to maintain the Dew Cure treatment below the 5% threshold without applying a single curative application of Daconil! At this location we were also able to see a recuperative effect within the Urea treatment, only requiring a single application. At North Shore Country Club we were able to reduce the curative applications by two when using DewCure. All other plots required the same amount of curatives, four apps. At Briar Ridge with DewCure, we were able to reduce the number of curative required by one. At Briar Ridge we did observe phytotoxicity by DewCure. On August 10 an application of all products were made at a time when temperatures were 90+ degrees and turf was entering drought stress. This resulted in severe injury by DewCure alone.

These biorational products may play more important roles in disease management programs as we continue to progress into a reduced input future. As we continue to learn and understand the benefits and limitations, superintendents will be able to make better and more informed decisions. We may as well investigate alternatives now before we run out of options.

The final picture shows a plot treated with Dew Cure resisting dollar spot without receiving any curative applications during the summer of 2010 at Coyote Run GC.

Tim Sibicky
TSibicky@cdga.org
Chicago District Golf Association
11855 Archer Avenue
Lemont, IL 60439

Weeds at the Hong Kong Golf Club

Recently I have been getting e-mails from friends and family back in Iowa telling me about all the weed pressure this season from the wet weather conditions. Their messages got me thinking about some of the weeds around here in Hong Kong and I thought it would be interesting to share about three different types of weeds that are an ongoing battle for us here at the Hong Kong Golf Club.

Goosgrass Eleusine indica
Goosegrass is a summer annual grass, which grows as a perennial here in our subtropical climate. Goosegrass pressure is intense on nearly all parts of the course and grows very well in compacted and high traffic areas. Recently, a pre-emergent herbicide plan has been implemented using Barricade and we have had great success. By using this pre-emerge program in the fairways, roughs and all other major play areas, we have saved a massive number of man-hours that were devoted to hand pulling weeds. We still have a crew of who spends a majority of their day walking the fairways with a weed removing tool and a trash bag trying to control the Goosegrass. At the end of the day most of the managers have filled up the back of their carts from pulling Goosegrass on their courses whenever they see a troublesome clump trying to take over.

Water Hyacinth Eichhornia crassipes
Water Hyacinth is a water dwelling weed that is incredibly invasive and can destroy the make up of a pond or lake. It quickly covers the entire top of a body of water, cutting out sunlight to lower levels, and sucks all the oxygen out. There was an article in the August edition of Golf Course Management (pg 40) about a new insect that they believe will help control populations of Water Hyacinth. Unfortunately, the insect is just being released in Florida and I do not know if it will ever be made useful here in South East Asia. Our current control method is again, manual removal. Every few months our landscape team will go in and remove all the Water Hyacinth from this pond. Unfortunately, if you leave just one leaf, it will be completely covered again. We are keeping our fingers crossed it does not invade other ponds on the course.




“Creeper” Mikania micrantha
Chinese Creeper, or more commonly known just as “Creeper” is a weed that has most of Hong Kong in its grips, literally. Creeper is a perennial weed that quickly grows and overtakes trees and all other vegetation. It smothers them from the light and eventually kills them. This vine can be seen taking over forests in the mountains and if anything sits for too long, creeper will eventually overtake it. Our arboriculture team regularly removes the vine from our tree lines here at the golf course. They do a great job keeping it from overtaking our natural areas, but it is a never-ending job. There are some chemical controls for it, but it is easiest and safest to just remove by hand and to try and keep populations at a minimum so it doesn’t get out of control.

Damian Richardson
Hong Kong Golf Club

Improving Accuracy of Disease Rating for Dollar Spot on Turf

Nick Christians
September 27, 2010

The following is a post from a student named Steve Johnson. He is an undergraduate who was working for Dr. Mark Gleason on a pathology research project this summer. He is doing this as part of the requirement for his Hort 391 special studies course. Hopefully, this will start a trend and we will have several other posts like it this fall.

Steve Johnson, Soph. Summer Intern Blog #1

Many turfgrasses are susceptible to fungal diseases and this leads to many maintenance issues for turf practitioners.  In response to the detrimental effects of turf diseases caused by a wide assortment of fungi, a precise reading of the amount of turf infected by a disease is needed to determine the proper course of action.

In evaluating alternatives for suppressing turf diseases, its important to have a method to separate the effective treatments and the from the less effective ones.  This often requires replicated field trials, often at multiple sites, comparing each alternative in the same turfgrass stand.  But how, exactly, does one measure disease severity.

Disease severity is usually measured by some sort of visual estimation method.  In other words, you look at the turf that was treated with each respective fungicide treatment and try to visually estimate a number a represents how severe the disease symptoms appear.  This is not always accurate and may not be consistent from one rating to the next or from person to person.

As an example of this, lets consider the turf disease dollar spot, caused by the fungus Sclerotinia homeocarpa. Dollar spot is a relentless disease that is recognized by it distinctive lesions that are often the size of the a silver dollar and the lesions can grow together in severe cases.  Dollar spot is the most expensive disease to control on golf courses across much of the Midwest and Eastern United States.

In comparing dollar spot fungicide treatments to each other, how can we measure disease severity?  One way is to estimate the percentage of the plot that has turned brown due to the disease.  But one person rating the percentage of dollar spot may come up with a different number than someone else.  Others have two people rate the same plot independently of each other.  So how can we be sure that the disease ratings are consistent and reliable? 

Evaluating a way to accurately estimate dollar spot severity on greens-height creeping bentgrass was the objective of this study.  We wanted to find out how different two people would rate the same turf plots, and then average the ratings to reduce bias from individual ratings.  A trial was conducted during the summer of 2010 at the ISU Horticulture Research Station to evaluate dollar spot severity on creeping bentgrass.

The results of this study are mean to be relevant for disease severity ratings of many diseases and grasses, not just bentgrass and dollar spot.  

Figures

Examples of turf from the Hort farm plots infected with dollar spot.

1 and 2.

ISU Horticulture Farm turf plot marked out for the experiment. The white string was used to show where the corners of each were.  We then spray-painted the corners in order to visually locate where each plot was without the strings.  The strings were removed after all the corners had been painted so regular maintenance could continue.

WOI green located just north of Roy J. Carver Co-Lab on the northwest edge of the ISU campus.  It was marked out and prepared for the experiment in the exact same manner as the plots at the Research Station.

Methods for Raising Sprinkler Heads

John Newton, CGCS, Veenker Memorial Golf Course is interested if anyone has a good method for raising sprinkler heads. If anyone has an alternative procedure beyond the traditional method of digging the head down to the swing joint, please share your thoughts by leaving a comment at the end of this post.

John’s question immediately made me think of the LeveLift system. I first learned of the LeveLift device during a presentation from one of our students who had interned at a golf course that had one. It’s definitely work checking out If you have never seen it before. The LeveLift was developed by a former golf course Superintendent. The device uses the water pressure from the irrigation system to lift the sprinkler head into a level position. You can see a video of the LeveLift system in action by clicking here.

Marcus Jones
Graduate Research Assistant

CREEPING BELLFLOWER IN AMES LAWN

Nick Christians
Sept. 22, 2010

Here is the unusual weed of the week. It came from an Ames lawn. It looks like Ground Ivy (creeping charlie) except it does not have a square stem and does not have the mint odor. Also, it is spreading by underground rootstalks and not above ground runners.

It is Creeping Bellflower (Campanula rapunculoides). It is an escaped ornamental that has become an invasive weed. It has a blue, bell-shaped flower at some times of year, but in mowed conditions may go most of the season without a flower.

It is hard to kill. It is resistant to 2,4-D and many of the other common lawn herbicides. You will need something with Dicamba in it and it will still likely take several applications. Luckily, it is rare in Iowa.

Fall is in the Air

A change of seasons is upon us.  The leaves are beginning to drop from some trees and the day lengths are getting noticeably shorter.  September has brought with it cooler day and nighttime temperatures and average 4-inch soil temperatures even dipped into the high 50’s yesterday.  These favorable environmental conditions have allowed existing turf the chance to recover and newly sown seed the opportunity to germinate and begin to cover.

The fall is also a great time to clean up unwanted creeping bentgrass.  Because of all the rainfall and submerged conditions we experienced during the summer months, creeping bentgrass had an opportunity to gain a competitive advantage and may have spread into areas where it wasn’t present before.  Luckily, creeping bentgrass can be controlled with Tenacity herbicide.

Tenacity is a systemic herbicide with pre- and post-emergence activity on many grass and broadleaf weeds.  Tenacity is also capable of selectively removing creeping bentgrass from Kentucky bluegrass, perennial ryegrass, tall and fine fescue.  Multiple applications of Tenacity are required for complete control of creeping bentgrass.  

Tenacity works by inhibiting HPPD enzymes which aid in the synthesis of carotenoids.  Carotenoids help to protect the plant from excess light energy received from the sun.  Without these protective carotenoids, the excess energy causes new growth to turn "bleach" or turn white and eventually kills susceptible plants.

I have done quite a bit of work with Tenacity.  Below are some pictures from my research and from golf courses who have used the product. 

 

Plot of turf adjacent to a creeping bentgrass putting green after recieveing one application of Tenacity herbicide.  The bentgrass (susceptible) turns white, while the Kentucky bluegrass remains unaffected.

Here, Tenacity was applied to an intermediate cut of Kentucky bluegrass to clean up creeping bentgrass that had invaded from the fairway.  Bleaching of the bentgrass appears after just 1 application.

Applying tenacity next to monostands of creeping bentgrass needs to be done with caution.  Here, spray drift from the adjacent treated turf caused bleaching symptoms on a creeping bentgrass green.  Bentgrass will not be completely controlled after one application but the "bleaching" symptoms can be unsightly in the wrong spot.

Multiple applications of Tenacity are needed for complete control of bentgrass.  Here, three applications have killed the majority of creeping bentgrass in a stand of Kentucky bluegrass. 

For more information about Tenacity herbicide and its various uses visit the Syngenta Tenacity page.

Marcus Jones
Graduate Research Assistant

Iowa Based Internships

Thinking back to when I was an undergraduate, I remember what a great learning experience my internships were.  I could finally start to apply some of the information I had learned in the classroom and I was able to communicate and interact with field experts on a daily basis.  Similarly, from my time spent in industry, I understand how staffing reliable, enthusiastic workers can benefit the day to day operations of any facility.  The bottom line is that internships can be beneficial to both the student and the facility alike.

Some of you may have had an intern from ISU at your facility in the past and others may be curious about employing an intern in the future.  Our department has approximately 50 turfgrass students who will be looking for internship opportunities this coming summer in golf, sports, and lawn and landscape settings. 

These potential interns (along with their resumes) will be available for an informal meet and greet at our upcoming Horticulture Career Night.  The event will be held on Monday, October 18 at Reiman Garden’s just south of the ISU campus.  The event will begin at 5:30 pm and food and beverages will be provided at no charge.  Consider coming to this event to recruit potential interns.  Those planning on attending need to RSVP to Marcus Jones at mjones99@iastate.edu.  

Marcus Jones

Graduate Research Assistant

MORE PCNB INFORMATION

Nick Christians
9/14/2010

Here is another post that just came in on the loss of PCNB and potential replacements for this fungicide. It is from Dr. Joe Vargas at Michigan State.



PCNB



As most of you know by now, PCNB may not be available this year, or in the future, for snow mold control due to a cancelation by the EPA. The law does allow distributors to sell any PCNB that they have in stock. It also allows golf courses to use any PCNB that they have in stock. What the EPA ruling does is prohibit the manufacturers from selling anymore PCNB to distributors or anyone else. Because we felt this would eventually happen, and for other reasons, we at MSU have been conducting studies in Northern Michigan at Tree Tops Resort and at the HTRC in East Lansing in search of PCNB replacements. The following suggestions for alternatives to managing snow mold without PCNB are based on 20 years of research. There may also be other fungicide combinations that may have similar efficacy, but these listed here are the combinations we have had success with over the years. Many of the fungicide combinations listed below already come as prepackaged combination products.



Snow Mold Species




There are two basic types of snow mold, Typhula blight, which is caused by two different species, and Microdochium Patch. Typhula incarnata, which is the major pathogen in southern Michigan and, during milder winters, in northern Michigan and Typhula ishikariensis, which is only found in Northern Michigan and is the most prevalent pathogen in more harsh winters are the two causes of Typhula blight in MI. Typhula sp. are more problematic on creeping bentgrass and perennial ryegrass. The other snow mold is Microdochium Patch, caused by Microdochium nivale, which is more of a problem in southern Michigan under snow cover. It is a problem throughout Michigan in the cool wet weather of spring and fall. Microdochium patch is more problematic on annual bluegrass.


Chemical Management



Below is an alphabetical list of snow mold fungicides based on their level of efficacy.


Fungicides listed by efficacy

Typhula blight control

Excellent
Chlorothalonil
Fludioxonil

Good
Myclobutanil
Propiconazole
Tebuconazole
Triadimefon
Triticonazole

Microdochium Patch Control

Excellent
Azoxystrobin
Fluoxastrobin
Iprodione
Mancozeb
Pyraclostrobin
Thiophanate-methyl
Trifloxystrobin
Vinclozolin

Good
Chlorothalonil
Polyoxin D Zinc Salt



Suggested fungicide combinations as alternatives to PCNB



The following are suggested fungicide combinations for snow mold control on greens and fairways in regions where snow does not cover the turf for long periods of time. These are also good alternatives for fairways where cost is a consideration, although complete control of the snow molds will not occur in years of severe pressure.



Chlorothalonil combination with:
Azoxystrobin or
Fluoxastrobin or
Iprodione or
Myclobutanil or
Propiconazole or
Pyraclostrobin or
Tebuconazole or
Thiophanate-methyl or
Triadimefon or
Triticonazole or
Vinclozolin or


The following are suggested fungicide combinations for snow mold control on greens and fairways in regions where permanent snow covers the ground for 3 or more months:



Azoxystrobin + Fludioxonil + Propiconazole
Azoxystrobin + Fludioxonil + Chlorothalonil
Fluoxastrobin + Chlorothalonil + Polyoxin D Zinc Salt
Myclobutanil + Fluoxastrobin + Chlorothalonil
Pyraclostrobin + Propiconazole+ Chlorothalonil
Tebuconazole + Chlorothalonil + Thiophanate-methyl + Polyoxin D Zinc Salt
Tebuconazole + Chlorothalonil + Iprodione
Triadimefon+ Fosetyl-Al + Iprodione
Triadimefon+ Fosetyl-Al + Trifloxystrobin
Triadimefon +Trifloxystrobin + Chlorothalonil
Triticonazole + Pyraclostrobin + Vinclozolin
Triticonazole + Pyraclostrobin + Chlorothalonil
Triticonazole+ Fosetyl-Al + Iprodione
Triticonazole + Fosetyl-Al + Trifloxystrobin

Pre-package 3 way mix
Instrata (Propiconazole + Chlorothalonil + Fludioxonil)

________________________________________
Dr. Joe Vargas, Michigan State

SUBSTITUTES FOR PCNB FOR SNOW MOLD CONTROL

Nick Christians
September 10, 2010.

Here is some information for Dr. Jim Kerns, the new turf pathologist at the university of Wisconsin. It is the Wisconsin recommendations for snow mold treatments for this winter if PCNB is not reinstated.

From Jim Kerns:

Here is what we've developed for superintendents in Wisconsin as substitutes for PCNB.

1. Good: 2 oz Thophanate-methyl + 5.5 oz chlorothalonil (this is a great mixture for pink snow mold and moderate gray snow mold pressure)



2. Better: 4 oz iprodione + 5.5 oz chlorothalonil (once again great for pink snow mold and moderate gray snow mold pressure 2 oz propiconazole (microemulsion formulations) + 0.3 to 0.5 oz Medallion (excellent for high pressure sites, but it fairly expensive)



3. Best: 4 oz iprodione + 5.5 oz chlorothalonil + 2 oz propiconazole (microemulsion formulation) 4 oz iprodione + 5.5 oz chlorothalonil + 0.72 oz propiconazole (concentrated EC formulation)


4. Supreme: 7 to 9 oz Instrata 4 to 6 oz Interface + 2 oz propiconazole (microemulsion formulation)


Other pathologists are also putting together recommendations. I will post those as they become available.

PCNB AVAILABILITY

Nick Christians
Sept. 9, 2010

Here is some important information from Dave Berg of Reinders, Inc. It is about the 'stop sale' order on PCNB just before the snow mold season.

In the past 72 hours, the professional turf industry has been made aware of an alarming situation regarding the availability of Amvac's PCNB fungicide. The attached letter from Amvac dated 9-7-10 describes the current situation regarding the EPA's 'Stop Sale' order on PCNB. In short, PCNB is not available today from Amvac and most likely will not be available for the 2010 fall season without a sudden and unexpected reversal by the EPA. Amvac already sought emergency injunctive relief in federal court over the weekend and was denied.

This stop sale order refers only to Amvac and the PCNB products is their possession. Current PCNB inventories of distributors, dealers, and end-users is not affected and may be sold and applied this fall. Per Amvac, virtually the entire 2010 season's new inventory for all U.S. distribution is still on the docks and can not be shipped. This action has caught everyone by surprise and needless to say all distributors are vigorously weighing options to replace PCNB and deliver cost-effective solutions for the industry.

We will share any new developments as they become known.

Dave Berg

Business Mgr

Reinders, Inc.

Here is the letter from AMVAC, makers of PCNB.

September 7, 2010
To: Terraclor, Turfcide and ParFlo Customers - United States
Re: PCNB – Stop Sale

Dear Valued Customers:

As you may have read from our press releases, last month the United States Environmental Protection Agency issued a stop sale order with respect to our PCNB product line within the United States on the ground that our product contained a trace impurity that is not listed on our confidential statement of formula (CSF). We were shocked and surprised at the order, as it was issued without any advance warning just as our main selling season was starting and related to an impurity about which we had notified the agency nearly 20 years ago.


By way of background, under FIFRA for each registered compound, a registrant is required to list in its CSF all components that either (i) constitute at least 0.1% (1 part per 1,000) of the compound or (ii) are determined by EPA to be of toxicological significance. In 1993, we informed EPA that our PCNB manufacturing process yielded a trace impurity. It was unclear then (as now) whether this impurity had to be listed on a CSF. The agency took that information without further comment. In 1998 and then again in 2005, that agency approved our CSF for PCNB without making mention of any of the trace impurity. Last June, we engaged in discussions with USEPA about our CSF with a focus on impurities and embarked upon what we thought would be a mutual effort to assess purity levels, manufacturing processes and our CSF disclosure.
Without furnishing any technical analysis, notice or opportunity to explain our position, the agency stopped sale of our product in August. Bear in mind that the stop sale order did not include any contention that our product poses any risk to health or the environment. Indeed we are talking about an impurity of less than 10 parts per billion or 0.000001%. We promptly called for meetings with USEPA to hammer out an informal resolution, but quickly determined that the matter had been effectively handed off to government lawyers.


In the interest of protecting our business and saving our season, we filed a motion for emergency
relief from the stop sale with the federal court arguing, among other things, that the issuance of the order amounted to the taking of our property without due process. Last Thursday, however, that court denied our motion. In making his ruling, the judge noted that although the agency’s actions were troubling and Amvac had been treated unfairly, the agency was legally permitted to take this action.


At this stage, we plan to amend our CSF and work as expeditiously as possible with USEPA to get this stop sale removed. We will also continue down the path of further litigation, as we continue to believe that the order is an abuse of process. However, there is no guarantee that the agency (or a court) will work through this issue in less than four months (which they are permitted under applicable law). As a result, we are not confident that we will be able to ship product to our customers in time for turf application in the late Fall and Winter of 2010. We sincerely apologize in advance if we are unable to supply your needs in time for your application. Nevertheless, we thought it best to give you ample time to protect your business interests as we work on this matter. We will, of course, keep you apprised of material developments as we learn of them.


Thank you for your understanding and support. We look forward to continuing to serve you when this storm passes. For your reference, we are also including a copy of our latest press release on the subject. If you have questions on the continuing status of this matter, please contact Jeff Alvis at 817.742.7423. If you would like us to send this note to anyone else in your organization, please contact Glen Anderson at 888.462.6822.

Why Research is Conducted Across Multiple Years

Starting a new research project is always exciting. It signifies the beginning of a journey to hopefully answer a specific set of questions. Often times, there are surprises along the way (some good, some bad) that you weren’t expecting. However, one of the frustrating aspects of research is that it is slow, and takes time.

It’s common for field experiments to last the duration of a growing season only to be repeated a second or third time in consecutive years. This can be annoying and confusing to the end users, the people who are awaiting the results of the project. So why is it that research projects are conducted across multiple years? Simply put, because of the environment.

Just think about the variation in the weather from last year to this year. Last year we experienced record low temperatures and moderate rainfall. This year we were treated to above average temperatures and record rainfalls. The difference in temperatures, coupled with the extremes in rainfall between the two growing seasons results in major inconsistencies in the growth and overall quality of our turfgrasses from year to year.

I’m seeing the influence of the environment in my interseeding study at Hyperion Field Club. The picture below shows two plots each receiving the same treatments or management strategy. The plot on the left is from 2009 and the plot on the right is from 2010. These particular plots each received 4 applications of Velocity herbicide on 14 day intervals at 2 oz/A starting the beginning of June and ending the middle of July. Each individual plot is split in half and received two different seeding strategies. The left side of each plot received multiple sowings of seed at 1.5 lbs/1000 ft2 every 14 days for a total of 13.5 lb/1000 ft2/year. The right side of each plot received two sowings of seed at the same rates for a total of 3 lb/1000 ft2/year.

Research plots from Hyperion field club in 2009 (left) and 2010 (right).  Each plot received 4 applications of Velocity. Why such a disparity in appearance?  The environment.

The plot from 2009 shows good color, no loss in turf density, and seedlings can be seen emerging on the left side of the plot. In contrast, the plot from 2010 appears slightly chlorotic and turf density has been severely compromised. Furthermore, germination of seedlings is scarce. Clearly, the weather was a huge factor in the response of these plots to the Velocity applications. To be fair, I do need to point out that the Velocity label warns of possible damage to creeping bentgrass under high heat stress during and directly following application which was experienced in 2010.

If you’ll remember from an earlier post, one of the surprises from this research was the high level of poa control we experienced from the Velocity applications. Based on the damage we saw from the summer applications during 2010 we have set up another trial to see if we can achieve good poa control with fall applications of Velocity. The idea is that applications during the fall will result in less damage to the creeping bentgrass. This trial has three treatments, 1) some plots will receive a September 1 application, 2) some plots will receive an October 1 application, and 3) some plots will receive an application on September 1 and October 1. All applications will be made at 2 oz/A.

We’ll be sure to let you know how it goes…next spring.

Velocity research plot (left) and untreated plot (right) at Hyperion Field Club.  The plots receiving Velocity had considerably less poa compared to untreated plots

Side project to determine if fall applications are effective at controlling poa.

Marcus Jones
Graduate Research Assistant

KENTUCKY BLUEGRASS RECOVERY FROM RHIZOMES AFTER FLOOD

Nick Christians
September 6, 2010

On the 24th of August, I posted some pictures of the ISU intramural fields following 3 days of continuous flooding. The warm-season grasses had recovered well from the flood, but the surrounding Kentucky bluegrass/perennial ryegrass area appeared to be dead.

The pictures below are from September 6, two weeks later. The area has been reseeded, but seedlings are not emerging at this time. The strip through the middle of the field are the warm-season grasses that recovered immediately after the flood. Notice the green area to the left. That is Kentucky bluegrass recovering from rhizomes.






The grass in the background is Kentucky bluegrass. No rye can be found in the area. The rye is a bunch grass and lacks a rhizome system. The rhizomes of the bluegrass are causing the recovery.





Here is a bluegrass plant growing at the end of a rhizome. This type of growth is what comprises most of the green tissue on the Kentucky bluegrass area.





A little digging in the area shows rhizome tissue just beginning to form new plants.


These new plants from these rhizomes will emerge in the next few days and begin to produce chlorophyll. I would expect recovery from rhizomes to be complete before fall and long before the new seedlings mature. Seeding is still a good idea on an area like this. The perennial ryegrass on the field will come from seed.

I'll keep you posted on the recovery through the fall.

Creeping Bentgrass Performance with Reduced Fungicide Inputs, Tim Sibicky, CDGA

Creeping bentgrass is used extensively on golf course fairways throughout the northern United States. It is typical for variety trials all throughout the country to use management practices where all diseases are controlled for comparison.

Currently, there is limited available research in cultivar testing for reduced fungicide input programs. Today, many golf course superintendents are looking to cut costs and reduce inputs to their largest acreages of highly managed turf, the fairways.

The objective of this work was to determine the susceptibility and performance of creeping bentgrass cultivars under a reduced fungicide input management program for dollar spot disease on fairways.

Twenty-four different cultivars of creeping bentgrass and one colonial bentgrass cultivar were selected for the study. Plots were established in October of 2008. Each plot is split in half with one half receiving fungicide applications and the other side receiving no fungicide. Fungicide applications of Daconil Ultrex at 3.2 oz. with Emerald at 0.18 oz are applied when a 5% percent threshold of dollar spot occurs on the cultivar ‘Declaration’.

Results:
The August 23 sampling date for the split plots shows that acceptable levels of visual quality are achievable when limiting fungicide applications. Best visually rated varieties under this reduced management include, Kingpin, Pennlinks II, SR1150, CY-2, Declaration, Shark, OO7 and Memorial. Cultivars rated at or below acceptable visual quality include T-1, Southshore, Imperial, Penn A4, Crystal Bluelinks, Bengal, Independence and Century. Meanwhile, all split plots left untreated produced unacceptable levels of turfgrass visual quality. These untreated plots had dollar spot levels up to 60-80% blighted turfgrass in some cases.

Tim Sibicky
TSibicky@chga.org
Chicago District Golf Association
11855 Archer Avenue
Lemont, IL 60439

The Weight of Water

The message below comes to us from John Ausen, CGCS, at Hyperion Field Club. (Perhaps a more fitting name based on their weather would be Hyperion Boat and Yatch Club).

John's Message:

Hyperion Field Club received 39.5 inches of rain from June 2nd to August 14th. Many golf courses received more and for that I sympathize with you. Keeping the 39.5” of rain in mind, this means that 3.25 cubic feet of water landed on every square foot of turf. One cubic foot of water weighs 62.5 pounds which puts the weight of 3.25 cub foot at 203 pounds.

If you consider a 5000 square foot green the total weight of water landing on that green was 1.1 million pounds or 507 tons and it all hit at the speed and force of gravity which is somewhere between 10 and 20 miles per hour depending on the size of the drops.

Any more questions about the need for aerification!

John Ausen