Wednesday, August 26, 2009

Research Update: Keith Rincker, Chicago District Golf Association

Dollar spot development in Chicago (2008 vs. 2009) and Tall fescue can get rust!

Rainfall has definitely returned after a dry July in Lemont. So the moisture component of the environment needed for fungal development has returned and with some cloudy nights the temperatures have been favorable too. Lately, dollar spot has taken off and so has brown patch here on Sunshine Course. After such a slow start for turf diseases this summer, I decided to look up the levels of dollar spot in our untreated plots at North Shore CC (north suburb) and Coyote Run GC (south suburb). In 2008 we had a slow start for dollar spot development, but we saw a large difference in our two locations. Now this year we had a cold spring combined with a cold and dry July. This year our two locations are more similar, but it is interesting to see that dollar spot at Coyote run is taking a similar spike as last year but the development is still a month behind (see graph below).



Our data at North Shore CC seems to be bouncing up and down this year as it did late last year. Why would we see that? Well Derek reminded me of all the differences between each site. Besides turfgrass differences of L93/Southshore vs. bentgrass/Poa annua blends and weather differences, there are differences in management. Dave Ward at Coyote Run has kept our plots on a practice facility dry. After dollar spot comes in less water keeps the bentgrass from recovering. There are many differences of each location, and that is just the reason for testing multiple years and locations. For now the research continues.

In other disease news, the rain has relieved moisture stress and rust is no longer an issue in our tall fescue trial. Rust is interesting that it tends to become visible during dry conditions but that is when the plants are stressed and rust pathogens do their best work. I made an attempt at rating the disease across all the varieties and was surprised to see some differences (see graph below). Some plots had many leaves affected which flagged bright yellow while other varieties were all green. Out of 58 varieties 2 showed the most symptoms with 10 percent of the leaves affected.






Derek Settle, PhD
Director of Turfgrass Program
Chicago District Golf Association
11855 Archer AveLemont, IL 60439

Monday, August 24, 2009

Algae crusts

Algae crusts can be a serious nuisance on golf course putting greens. When conditions are favorable, algae crusts can form a thin layer on top of the turf canopy blocking light and impeding the movement of water and air into the rootzone. The pictures in this post came courtesy of Pat Franklin, CGCS, who encountered an unexpected algae outbreak this summer.

Algal occurrence and development is most common during the summer months when high air and soil temperatures result in turf thinning. Algae is most likely to develop in areas of the green which have thin turf cover allowing air, light, and water to reach the thatch surface. Areas with poor drainage and excessive shade further promote algal growth. The presence of phosphorus also encourages the development of algae. Unfortunately, algae can appear in situations where proper cultural practices are the routine and the turf is relatively healthy. The outbreak Pat experienced occurred after a period of wet weather.

So if you find yourself in this situation what is the best way to control algae? The best method of controlling algae is through a preventative management program:

Water- Water management and proper drainage is critical to preventing algae. Remember, algae need surface water to develop and grow so proper irrigation scheduling is critical. Cultural practices such as topdressing and aerification that help keep the upper soil layers dry will also help.

Fertility - Phosphorus appears to be a key component for the development of algae. Using products that lack phosphorus or reducing phosphorus application rates is recommended.

Chemical controls – Although cultural controls help, algae often occurs despite your best efforts. In these situations, fungicides are needed to effectively control the problem. Ammonium sulfate and hydrated lime are effective at “burning” the algae but these products can also very easily “burn” the turf. Chlorothalonil and mancozeb are very effective products and are much safer to the turf. Pat effectively controlled his algae problem with Fore fungicide. If making curative applications, it is recommended to spray on a 7 to 14 day interval at high label rates. The lower label rates may be used as part of a preventative spray program. Additional fungicide applications are often recommended even after the symptoms of algae have disappeared as algae can return quickly if the conditions are favorable.

For more information regarding algae and it control see the following links:

http://www.grounds-mag.com/mag/grounds_maintenance_algae_crusty_foes/

http://www.turffiles.ncsu.edu/Diseases/Algae.aspx

Marcus Jones
Graduate Research Assistant

Thursday, August 20, 2009

Rust - To treat or not to treat

Rust occurs every year on Iowa turf but as a general rule fungicide applications are not necessary. This year may be the exception to that rule. Several calls with specific circumstances have led me to recommend fungicides for rust control. Before we get to the rest of the story let’s review the normal approach to dealing with rust. As diseases go, rust can be easily identified by the yellow to orange flecks that develop on leaves and stems. As the disease progresses orange and cinnamon colored blisters and pustules form. Clouds of spores can turn your shoes orange when walking through turf heavily infested with rust.

- Rust occurs on Kentucky bluegrass and perennial ryegrass, but we are even seeing it on tall fescue this year. Immature turf that was seeded in the spring or early summer has been especially impacted by rust this year.

- Rust is usually more severe in turf that is growing slowly. Low light intensity, inadequate fertilization (especially nitrogen), drought stress, and infrequent mowing encourage rust development. A little extra shot of nitrogen is usually all that is needed to stimulate leaf growth that allows mowing to remove infected tissue. The idea is to keep the grass growing fast enough so that grass clippings are generated each week. Sufficient nitrogen and irrigation are required to “out grow” the rate of rust infection. If the grass stays at the same height and mowing is not needed, then rust can eventually cover the entire plant.

- Excessive irrigation and irrigation practices that extend the period of free moisture on the leaf surface encourage rust. The best time to water is at dawn because the turf is usually already wet from dew. Avoid watering from 10 am through dusk, this only extends the period of leaf wetness. Night time irrigation, after dew has formed, would be the next best time for watering to reduce rust.

Hopefully most of you may not need to justify a fungicide application. Those of you with actively growing turf may not be experiencing severe rust problems as the summer season begins to wind down. Golf Course Superintendents may choose to accept some turf injury on lower priority areas such as golf course roughs with the expectation that recovery usually occurs later in the autumn. However, here are the circumstances from my university extension visits that have resulted in fungicide recommendations to control rust in 2009. Most of them involve athletic fields.

- Most of the calls have come during late July and early August so that only leaves about 30 days until the field will open for play. If we have extended conditions in September that favor rust infection, high traffic areas will quickly fade.

- Three calls had fields that were newly seeded in the spring and early summer. Germination and establishment were going quite well with the mild summer temperatures this year. However, the establishing grass did not have substantial vertical growth so when the rust hit, it quickly covered the entire plant and growth completely stopped. Four lbs of N per 1000 sq.ft. had already been used on the native soil field during establishment so the manager was reluctant to use more nitrogen that could incite other summer turf diseases such as brown patch and pythium. It is full of rust and they want to play football in 14 days. I recommended a fungicide and another pound of nitrogen. At a separate spring seeded field they were using a rain train to irrigate. It takes three 8-hr sets to irrigate the entire field so the rain train was running 24-7 for over a month. That also means that leaves were wet for too long because half of the water was being applied during the day time. The field was covered with rust and turf growth had stopped. I recommended a half pound of nitrogen per 1000 sq.ft., a rust control fungicide, and cutting back on irrigation by only watering for one 8-hr set during the night from 10pm to 6am.

- Another field had no means of irrigation and was intended for practice only. The worn field was over-seeded in May and the grass was establishing nicely with the mild summer, but again the new turf was stunted and covered with rust. For this field I recommended a pound of nitrogen per 1000 sq.ft., but did not recommend a fungicide. It just didn’t seem logical to apply fungicides when turf was not irrigated.

- Fungicide Treatments – It is unlikely that fungicides would reduce the blemishes on plants that were already infected. New growth is very important to recovery from existing rust. The fungicide applications were intended to reduce infection on new growth. Some of the fungicides that I recommended for this control strategy were: azoxystrobin (Heritage), chlorothalonil (Daconil Ultrex), propiconazole (Banner MAXX), and triadimefon (Bayleton).

It has been a peculiar year with little pressure from our typical turfgrass diseases. This year I found myself recommending fungicides to control, the normally non-destructive, rust on athletic fields where the disease pressure could have adversely impacted the football playing season.

Dave Minner

Wednesday, August 19, 2009

Disease Review: Dollar Spot

The time for the second application of fungicides on the new bentgrass research at the ISU horticulture research station has arrived. Chris Blume and I applied the curative, second treatment of Emerald® (boscalid) and Daconil® (chlorothalonil) today, August 18, 2009. The new bentgrass research is focusing on the susceptibility of different cultivars of bentgrass to the disease dollar spot. In the study, each plot is split, one side receiving no fungicides, while the other is treated with both a preventative and a curative application of boscalid and chlorothalonil. This year has proven to be an excellent year for dollar spot out at the research station and many of our bentgrass areas are spotted with the disease.

The disease dollar spot is caused by the fungal pathogen Sclerotinia homoeocarpa. This disease commonly infects many of our cool-season grasses. Dollar spot is a particular concern on bent/poa greens where the sunken pockets may interfere with putting quality. Dollar spot can develop over a wide range of temperatures (55-80°F) when the dew persists for long periods of time (longer than 8 hours). Dollar spot is also considered a low nitrogen disease and is most severe on nitrogen deficient stands of turf.

The pathogen causes blighted, circular patches of turf which are similar in size to a silver dollar (rarely larger than 2 in. in diameter) on low mown areas, and up to 6 in. or more in diameter on taller mown areas. The blighted spots of turf often occur in clusters and may merge together to produce larger blighted areas as disease development progresses. Active dollar spot infections produce a cottony white mycelia mass that is often evident on the turf during the early morning hours. When viewed under a microscope the mycelium will exhibit y-shaped branching and the presence of septum unlike the mycelia of pythium that are void of septum. In addition to the mycelia mass that may be visible, this pathogen also causes leaf lesions that have light tan centers and a red-brown margin. The leaf lesions of dollar spot are more commonly observed on taller turf species, such as Kentucky bluegrass, where the lesions take on the shape of an hour glass.

There are many ways to control dollar spot. One important management technique is to implement a satisfactory nitrogen fertility program. Nitrogen deficient stands of turf are more susceptible to dollar spot outbreaks. However, over stimulating with nitrogen may increase disease pressure from other, less desirable, diseases. Another option in control is to choose a less susceptible cultivar. Although there are no completely resistant cultivars of bentgrass, there are cultivars that are more resistant than others. For example, the cultivar Crenshaw® is far more susceptible to dollar spot than the cultivar Declaration®. Irrigation practices that limit the duration of leaf wetness will also help limit the occurrence of the disease. There are also fungicides available for the control of dollar spot. These fungicides often require multiple applications to effectively control this disease. Also, fungicides that are classified as site specific inhibitors have a high risk of resistance development and their repetitive use should be avoided. Some effective fungicides are Emerald®, Daconil®, Curlan®, and Tourney® along with many others.

Nick Dunlap



Tuesday, August 18, 2009

DOLLAR SPOT 2009

This has been quite a year for the development of dollar spot on bent in central Iowa. The two videos were taken at the horticulture research station on Aug. 18, 2009.

Nick


video video

Monday, August 17, 2009

Chicago/Northern Illinois Update: DSettle@cdga.org …reporting from Chi

Testing. Testing. Testing. Yes it is working...my typewriter. I mean my lap top computer with Microsoft Office Word 2007 ®. Knowledge...that was what I wanted to talk about this week. How do we get it. As a former un-named professor of mine, Dr. Ned Tisserat, used to say... “You buy them books, send them to school...”. I can’t remember the rest. The other classic quote I do remember clearly is, “What were you think-in?” In no uncertain those two quotes were used in tandem. I had made a mistake in my research. He was holding me accountable...and after my eyes got big and my palms started to sweat I would say “I don’t know what I was thinking.” He would say something like “That’s OK...I have done that too.” He was a wise-one that Dr. Ned Tisserat. He taught me how to question everything. He taught me I should try and prove what I was saying via a set of skills called science, “...sounds like another research project”. He taught me to be very generous and to listen before I talked...I think I can.

Anyhow, life is good. It has been a summer from God like no other. It has been a wonderful year to be a golf course superintendent. However, the weather has been off and remains off. We were overly cool in May, then overly cool til the 3rd week of June. The 3rd week of June marked an all time record of rainfall from Jan to Jun. Then it got dry and we continue to brown as far as unirrigated Kentucky bluegrass lawns and golf roughs go. It also marked the hottest period of summer (so far). It challenged us all because during that string of 90+ degree days we should have not made any applications and yet we did. In the name of science, in the name of a calendar, in the name of preventing fungal pathogens of turfgrass, in the name of xxx? Just fill in the blank. The point is you need to think. If we do not think, we risk making mistakes. We all had Ned’s in our lives – someone who holds our feet to the fire and makes us accountable. Let’s think first...then we can be spared from one of my life’s favorite quotes...”What were you thinking?” Summer is now waning... Labor Day is September 7, 2009. So enjoy the next 21 days...summer is about over and we saved a lot of money on fungicides during this ‘peak’ golf season. Rounds are up now that it is dry, and so am I...up! Stay up...21 days to go!

Derek Settle, PhD
Director of Turfgrass Program
Chicago District Golf Association
11855 Archer Ave
Lemont, IL 60439

Friday, August 14, 2009

Japanese Pagoda Tree

The answer to the "Do You Know This Tree" post that appeared last Friday is the Japanese Pagoda Tree (Sophora japonica). This tree was planted at Hyperion Field Club after the storm in 1998 that damaged so many of the trees on the golf course.

The Japanese Pagoda Tree is native to China and is sometimes referred to as a Chinese scholar tree. The tree will grow to an approximate height of 65 feet and displays a rounded crown. This species is one of the last of the larger trees to flower in the north. The Japanese Pagoda Tree blooms in late summer/early fall producing large upright panicles of mildly fragrant, creamy-white, pea-like flowers. The tree produces a fairly light shadow which allow for turfgrasses to grow underneath the canopy.




















John Ausen
Hyperion Field Club

Thursday, August 13, 2009

Disease Review: Brown Patch

It seems as if summer has finally caught up with us. An unusually mild July has left us and August has brought with it more typical Iowa summer weather. With increasing temperatures and humidity, coupled with the rain we received this past weekend, conditions have once again become favorable for disease development. Out at the ISU Horticulture Research Station we started our week off by discovering an outbreak of brown patch on some of our creeping bentgrass greens.


The turfgrass disease known as brown patch is caused by the fungal pathogen Rhizoctonia solani and can affect all of the cool-season turfgrass species. Brown patch is a summer disease whose development is triggered by hot, humid weather, night time temperatures above 65°F and long periods of dew. During these conditions brown patch may appear overnight. Brown patch is also considered a high nitrogen disease and excessive amounts of nitrogen in your fertility program during the summer can contribute to a brown patch problem.


Brown patch usually produces a circular brown to olive green patch with a grey perimeter giving a ‘smoke ring’ appearance. Often, more than one patch will be evident in an affected area with the appearance of the unique ‘smoke ring’ pattern more clearly defined on low mown turf. Individual leaf blades of the affected turfgrass will show lesions with a chocolaty brown margin. The brown patch lesions are most visible when observed on tall fescue, although they are present on all turfgrass species infected with brown patch.

One of the easiest ways to decrease disease pressure from brown patch is to implement a proper fertility program to avoid excess nitrogen during the summer months. Also, trying to promote shorter dew periods by avoiding late evening irrigation can help reduce the possibility of a brown patch. There are also a number of fungicides that provide brown patch control such as Heritage, Daconil, Medallion, Clearys 3336, and many others.

Nick Dunlap
GCSAA Campus Representative
Turfgrass Management
Iowa State University
njdunlap@iastate.edu

Wednesday, August 12, 2009

BROWN PATCH VIDEO

video

The video in this post is a experiment on the use of my new video camara. Let me know if you are able to view it by commenting below, or by e-mailing me at nchris@iastate.edu.

Nick

Tuesday, August 11, 2009

THANK YOU TO THE TORO GIVING PROGRAM

The turf program at Iowa State would like to thank the Toro Company and the Toro Giving program for providing a very generous gift of $25,963.20 in irrigation equipment for use at the turfgrass research center. An additional $4500 in cash was provided for the students to attend student contests at the GIS and the STMA meetings, for a total gift of $30,463.20.

Thanks from all of us at Iowa State. This was a very important gift during these tough economic times.

Nick Christians

Monday, August 10, 2009

Renovating with Basamid

Renovation season is just around the corner and there are a couple different options available when regrassing. Traditional renovation methods involve killing the existing area with a non-selective herbicide before re-establishing. Soil-fumigant type materials are often used on putting greens to eliminate weed seeds, soil-borne diseases, and nematodes. Methyl bromide, a colorless, odorless soil fumigant, works very well but is being phased out and soon will not be available for use. Basamid can be used as an effective alternative.

Basamid is currently the only granular soil fumigant on the market. The product is activated when moist soil converts the granular material to a gaseous compound which disperses through the soil. Below are some tips for using Basamid. Complete application instructions and label information can be found at the Certis website (http://www.certisusa.com/index.htm) and should be consulted before using this product.

Tips for using Basamid

Properly prepare the area – The effectiveness of Basamid will depend on how well you prepare the area. There are two options for preparing areas with cool-season grasses:

1) Scalp the area to be renovated as low as possible. Core aerify the area (possibly multiple times) and remove the cores before applying Basamid.

2) Cut and remove sod from the area to be renovated. Till the area to alleviate compaction and regrade before applying Basamid.

Regardless of the method you choose, the key point to remember is the more disruption you create, the more effective the product will work.

Obtain a quality drop spreader – Since Basamid is a granular material the only application equipment needed is a drop spreader. However, the product is extremely fine-textured so make sure your spreader is able to completely close to avoid misapplying any product.
















To cover or not to cover – After applying the Basamid, the surface of the soil must be “sealed” to keep the gas in the soil profile. This can be achieved a couple of different ways. One option is to apply irrigation for 5-7 days after application to keep the soil sealed. The other option is to cover the treated area with an impervious tarp. In my experience, tarping the area is well worth your time. Research also shows that using tarps results in greater control of annual bluegrass seeds. If irrigation is to be used, avoid overwatering especially on slopes to prevent the material from washing towards desirable plants and water.





























Conduct a germination test before planting – The labels lists 10 to 12 days as the interval you should wait before reseeding. To be sure, it’s a good idea to conduct a safety germination test. Take a small amount of soil from each treated area and fill a jar or paper cup with each sample. Sow a small amount of lettuce seeds in each sample and see what germinates. If the safety germination test is a success then it’s safe to plant your seed.

For more information and tips regarding Basamid for golf course renovations see: http://www.certisusa.com/pest_management_products/fumigant/basamid_g_turf.htm

Marcus Jones
Graduate Research Assistant

Friday, August 7, 2009

Do you know this tree?

You've seen and identified some unusual weeds on this blog. Do you know the name of this tree? The pictures were taken on August 4th at Hyperion Field Club in Johnston, IA.

John Ausen
Hyperion Field Club




Tuesday, August 4, 2009

ALL-IOWA HORT. FIELD DAY, THUR, AUG 6


Don’t forget the All-Iowa field day this Thursday Aug. 6. There is more information and a map at

The 2009 Iowa Turfgrass Report can be found at http://www.hort.iastate.edu/turfgrass/



For those who wish to show equipment or products, set up will begin at 6:30 AM on Thursday. You just need to register. There is no additional charge for showing equipment.

Nick Christians

Nick Christians
Iowa State University
Department of Horticulture
133 Horticulture Bldg.
Ames, IA 50011
515-294-0036
nchris@iastate.edu

Monday, August 3, 2009

SUMMER INDUCED CHLOROSIS


It's that time of year again when summer induced chlorosis begins to show up on lawns, golf courses, and sports fields. I have already had a few calls on this problem. Summer induced chlorosis is a yellowing of the turf that occurs as temperatures rise in midsummer. We normally see it in late July and into August. This year has been a little cooler than normal, but the few warm days that we have had are triggering the problem in some areas.

David DeVetter, a graduate student at ISU, completed a masters project on this in 2007. Here is the link to the article.

Nick Christians

http://www.hort.iastate.edu/turfgrass/pubs/turfrpt/2008/PDFfiles/GCMdealingsummer.pdf

Renovating with Basamid

Renovation season is just around the corner and there are a couple different options available when regrassing. Traditional renovation methods involve killing the existing area with a non-selective herbicide before re-establishing. Soil-fumigant type materials are often used on putting greens to eliminate weed seeds, soil-borne diseases, and nematodes. Methyl bromide, a colorless, odorless soil fumigant, works very well but is being phased out and soon will not be available for use. Basamid can be used as an effective alternative.

Basamid is currently the only granular soil fumigant on the market. The product is activated when moist soil converts the granular material to a gaseous compound which disperses through the soil. Below are some tips for using Basamid. Complete application instructions and label information can be found at the Certis website (http://www.certisusa.com/index.htm) and should be consulted before using this product.

Tips for using Basamid

Properly prepare the area – The effectiveness of Basamid will depend on how well you prepare the area. There are two options for preparing areas with cool-season grasses:

1) Scalp the area to be renovated as low as possible. Core aerify the area (possibly multiple times) and remove the cores before applying Basamid.

2) Cut and remove sod from the area to be renovated. Till the area to alleviate compaction and regrade before applying Basamid.

Regardless of the method you choose, the key point to remember is the more disruption you create, the more effective the product will work.

Obtain a quality drop spreader – Since Basamid is a granular material the only application equipment needed is a drop spreader. However, the product is extremely fine-textured so make sure your spreader is able to completely close to avoid misapplying any product.

To cover or not to cover – After applying the Basamid, the surface of the soil must be “sealed” to keep the gas in the soil profile. This can be achieved a couple of different ways. One option is to apply irrigation for 5-7 days after application to keep the soil sealed. The other option is to cover the treated area with an impervious tarp. In my experience, tarping the area is well worth your time. Research also shows that using tarps results in greater control of annual bluegrass seeds. If irrigation is to be used, avoid overwatering especially on slopes to prevent the material from washing towards desirable plants and water.

Conduct a germination test before planting – The labels lists 10 to 12 days as the interval you should wait before reseeding. To be sure, it’s a good idea to conduct a safety germination test. Take a small amount of soil from each treated area and fill a jar or paper cup with each sample. Sow a small amount of lettuce seeds in each sample and see what germinates. If the safety germination test is a success then it’s safe to plant your seed.

For more information and tips regarding Basamid for golf course renovations see: http://www.certisusa.com/pest_management_products/fumigant/basamid_g_turf.htm

Marcus Jones
Graduate Research Assistant