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.
This blog was created to provide Golf Course Superintendents in the State of Iowa with a convenient way to communicate and collaborate with peers, industry professionals and educators. Interesting things are happening across the state, and this blog will serve as a vehicle to share articles, links, and pictures with turfgrass professionals in the state of Iowa. Anyone is welcome to submit to iaTURF. It's as simple as e-mailing your submission to iaturfblog@gmail.com. I look forward to hearing from you!
Marcus Jones
Graduate Research Assistant
All article submissions will be posted at the discretion of the blog administrators. We reserve the right to decide what articles will be added to this blog.
Meteorologists in Iowa are calling it the coldest winter on record in the last 35 years, but what does that mean for my turf? Is it still alive?
The statewide avg. temperature in the last three months was 14.7 degrees, well below the 22.1-degree normal, according to State Climatologist Harry Hillaker. In addition to the extreme cold, snowfall varied considerably acrosas the state. Western Iow received far less snowfall and had a higher frequency of days above freezing. This could raise more concerns because of the increased exposure to the elements.
Research from Hoffman et al., (2010) at the University of Massachusetts-Amherst found that annual bluegrass has a lethal temperature with 50% death (LT50) at an approximately 0.1F, while creeping bentgrass has an LT50 between -6 and -16F. These numbers are of particular concerns in relation to the 15 (Shenandoah) to 50 (Decorah) subzero days this winter across Iowa. Direct low temperature death has several factors that include hardiness level, freezing rate, thawing rate, number of times frozen and post-thawing treatment (Beard, 1973).
Below you will find a chart looking at the low temperature hardiness of several turfgrass species produced by Beard (1973).
|
Low-temperature hardiness |
Turfgrass species |
|
Excellent |
Rough bluegrass |
|
Creeping bentgrass |
|
|
Good |
Kentucky bluegrass |
|
Colonial bentgrass |
|
|
Medium |
Annual bluegrass |
|
Tall fescue |
|
|
Poor |
Perennial ryegrass |
With hopefully the cold weather behind us and the last little bit of snow melting, we can start looking towards the 2014 growing season. The first step is to determine whether my greens or athletic field is alive. The best way to tell is by taking a soil sample (circular saw works well) and placing it in a greenhouse or inside where it will receive adequate light, nutrients, water, and warmer temperatures. If you begin to see new green color and growth within a few weeks, you should be fine.
The following pictures are from Brent Smith while visiting western Illinois. I feel with a little care and fertilizer in the spring these greens should be looking great by late May, early June. In some cases, it is just a guessing game, but there is enough green tissue in the picture to convince me that they will be good. If you have large areas without green tissue, alternative options may need to be considered (sodding or interseeding).
Today, temperatures finally began to climb out of the negatives. With the onset of warmer weather, (using this term gently) I felt it was a good time to start looking towards spring. Over the last few months there have been several inquiries regarding lawn fertilization. In response, I have revised the Iowa State University home lawn fertilization publication. Although you will not be pulling out the fertilizer bag for another 4-5 months, I thought I would inspire you with some information that will get you ready for warmer weather. The publication outlines the importance of fertilization, rates and timing of application, label requirements in Iowa, and fertilizer products in the market.
The following is a small excerpt from the introduction.
Lawns are an important component of many home landscapes. Good cultural practices are necessary to achieve a healthy, attractive lawn. One important cultural practice is fertilization. The benefits of a well-maintained lawn fertilization program are good turf color, quality and density. There are 14 elements which are often referred to as mineral nutrient elements and are generally obtaining in the soil via root extraction. The quantity of most of these nutrients contained in the soil is high compared with the requirements of turfgrass plants. However the demands for nitrogen, phosphorus, and potassium oftenexceed the supply in the soil. Thus, it becomes necessary to add these elements through fertilization.
Turfgrasses require nitrogen (N) in the largest amount of any of the essential nutrients. For this reason, nitrogen is usually applied in the largest amounts. Nitrogen nutrition is important to turfgrasses because it canaffect shoot growth and density, root growth, and susceptibility to damage from disease, heat, cold, and drought.
Turfgrasses require potassium (K) in relatively large amounts, second only to nitrogen. Potassium influences turfgrass rooting, disease susceptibility and drought, heat, and cold hardiness. The terms soluble potash, soluble potassium and K20 may be used to refer to potassium fertilization.
Phosphorus (P) is required by turfgrass plants in smaller amounts than nitrogen and potassium. Phosphorus is important in the establishment, rooting, maturation,and reproduction of turfgrasses. The terms available phosphate, available phosphorus, available phosphoric acid, and P2O5may be used to refer to phosphorus fertilization.
The entire extension publication is attached in pdf form. To download the publication, click on the following link Fertilizer Publication.
It is just about time to close the books on the 2013 season. Most turf managers have blown out irrigation systems and started thinking towards preventative snow mold applications and equipment maintenance.With colder weather moving in (-1 wind chill Monday night) and snow-flakes flying on/off the last few weeks it is time to find a nice warm spot and catch up on what has transpired this season. In addition, it is time to start looking towards conference season. I have provided a quick chronological list of the midwest turf conferences over the next few months. I look forward to seeing you there!
Missouri Green Industry Conference
December 5, 2013
St. Charles Convention Center
St. Charles, Missouri
http://www.hortco-op.org/_ccLib/attachments/events/MGIC+2013_SCHEDULE.pdf
Common Ground Conference (Heartland Green Industry Expo)
December 16-17, 2013
Overland Park Convention Center
Overland Park, Kansas
http://www.hagcsa.org/storage/Registration%20Form%20%20Schedule%20-%202013.pdf
Nebraska Turf Conference
January 7-9, 2014
LaVista Conferencer Center
LaVista, Nebraska
http://www.nebraskaturfgrass.com/wp-content/14-schedule.pdf
Illinois Turf Conference
January 7-8, 2014
McDonald's Campus
OakBrook, Illinois
http://www.illinoisturfgrassfoundation.org/Default.aspx?pageId=1390024&eventId=716011&EventViewMode=EventDetails
MNLA / MTGF Northern Green Expo
January 8-10, 2014
Minneapolis Convention Center
Minneapolis, Minnesota
http://northerngreenexpo.org/content.asp?pl=4&contentid=4
Wisconsin Turfgrass Research Day
January 14, 2014
Pyle Center
Madison, Wisconsin
http://www.wisconsinturfgrassassociation.org/EXPO.htm
STMA Annual Conference and Exhibition
January 21-24, 2014
Henry B. Gonzalez Convention Center
San Antonio, Texas
http://www.stma.org/2014-conference
80th Annual Iowa Turfgrass Conference & Trade Show
January 28-30, 2014
Downtown Marriott Hotel
Des Moines, Iowa
Sponsored by ITI, Iowa GCSA, ISTMA, IPLCA
http://www.iowaturfgrass.org/iticonference2014.htm
GCSAA Education Conference & Golf Industry Show
February 1-6, 2014
Orange County Convention Center
Orlando, Florida
http://www.gcsaa.org/conference/and http://www.golfindustryshow.com/
This article comes to us from Rick Tegtmeier, CGCS, Des Moines Golf & Country Club.
At DMGCC, we are like many other golf courses in Iowa, we have poa annua and we try to control the ugly seed heads that emerge in the spring. Many different types of growth retardants are used and we are no different. We use a combination of Primo and Proxy to control our seed heads. When we spray it on our fairways we use the following rates of PGR: Primo at 5 oz per acre (.11 oz/1000) and Proxy at 220 oz per acre (5 oz/1000). This is commonly referred to as the 5 and 5 program.
One thing we all struggle with is to when we start spraying the turf. In the case of poa annua seed heads, control must be done well ahead of the emergence of the seed head from the sheath area of the plant. We have found that using a Growing Degree Calculator has been our best tool to get the timing correct on when we do our first spray. I use a simple Excel spreadsheet to enter my daily temperatures and it automatically figures the cumulative total of Growing Degree Days.
My good friend Steve Cook, CGCS, MG,Director of Agronomy at Oakland Hills Country Club wrote an explanation on Growing Degree Days for his membership and I have included a little bit of that here. One thing to note is to make sure you know what model (base) of GDD calculator you are using. We use the 32 degree base at DMGCC and some people use the 50 degree base. Just make sure your cumulative days match your model!
Here is Steve’s explanation of GDD and how it affects the plant:
The growth rates of many biological organisms are determined by temperature. As temperatures increase, activity increases. One of the ways we measure the biological activity of plants and insects is Growing Degree Days or GDD. Knowing the GDD allows us to monitor a specific number and apply plant protectants (like insecticides) at the appropriate time in an organism’s life cycle to maximize control. It has applications for plants like crabgrass or poa annua as well. What is GDD and how is it calculated? We assume that an organisms growth rate increases as the temperature rises above a predetermined base temperature. Each organism may be given a specific base temperature. Knowing these activity thresholds is important and we monitor them depending on our target pest and optimal treatments.
This year the timing is much earlier than we normally spray. We do 2 sprays in the spring to control those pesky seed heads. There are some studies out there that advise you when to make the second application as well. This too is based on cumulative GDD’s. Until more work is done though, we will continue our program of spraying 21 days after the 1st spray. We typically apply some ferrous sulfate with the 2nd spray to mask some of the PGR effects. If you would like a copy of our Excel Spreadsheet shoot me an email and I would be happy to share it with you.
Rick Tegtmeier, CGCS
Des Moines Golf & Country Club
Iowa State University Turfgrass is pleased to announce the launch of its fully-featured website https://www.extension.iastate.edu/turfgrass/. The new site has extensive content including blog posts, publications, research reports, and news from across the state of Iowa. The highly successful IATurf Blog that reaches thousands of individuals will now be accessible from your tablet and phone.
The new website is designed to assist turf managers across Iowa with a one-stop shop for everything turfgrass. The website focuses on making information available to all individuals with a vested interest in turf industry, as well as highlight specialized advice and turf solutions. As part of our objective to provide critical information on the turf industry, Iowa State is proud to introduce the new website. Along with the launch of the new website, there are nine new publications added to the Iowa Extension store.
The first set of publications address common homeowner questions. As temperatures warm and the calendar steadily marches forward, people across Iowa will soon find themselves working in their yards on a regular basis. With this work in mind, Iowa State University Extension and Outreach has published four publications to serve as guides for residential yardwork. The full press release highlighting the publications can be found here! The following publications can now be found on the new site under the publication tab.
“Sodding a New Lawn”, (HORT 3033)
“Mowing Your Lawn”, (HORT 3047)
“Management and Control of Summer Patch” (HORT 3049)
“Organic Turfgrass Fertilization” (HORT 3031)
In addition to the general homeowner publications, five new publications focused on athletic field management were released. These focus on the planning required to keeping Iowa athletic fields aesthetically pleasing and more importantly safe. Managing traffic, interseeding and general maintenance of the field before, during and after the playing season are all important aspects to providing a smooth, even playing surface.
The full ISU press release can be found here! The following publications can also be found on the new site under the publication tab.
“Preventing Compaction on Athletic Fields” (HORT 3020)
“Tips for Athletic Field Seeding and Irrigation” (HORT 3022)
“Managing the Field within the Field” (HORT 3046)
“Putting the Field to Bed” (HORT 3048)
Topdressing Athletic Fields (HORT 3050)
Check out the new website and let us know what you think!
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
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 http://www.ipm.iastate.edu/ipm/hortnews/2008/7-30/update.html
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 http://web.extension.uiuc.edu/state/newsdetail.cfm?NewsID=13830
(*NOTE: For more information on the ISU Extension Restructuring see our web site at https://www.extension.iastate.edu/restructuring.htm)
Donald Lewis
Extension Entomologist
104 Insectary Building
Iowa State University
Ames IA 50011 USA
http://www.ent.iastate.edu/
