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Friday, May 15, 2015

Dollar Spot and Leaf Spot


Over the last week, dollar spot and leaf spot have popped up across the state of Iowa.

Dollar spot is usually considered an early to mid-summer disease and seems to be about a month ahead of last year. It is caused by the fungal organism Sclerotinia homoeocarpa. Most of the damage I have seen this spring has occurred on bentgrass greens, tees, and fairways. The symptoms of dollar spot on close mown turf (such as bentgrass) are small, tan-colored spot equal to or smaller than 2.5 inches across. The name of Dollar Spot comes from the silver dollar-sized turf damage. Spots can be numerous and coalesce, making identification difficult. Dollar spot is most notable on nitrogen deficient turf. By increasing fertility, you can reduce future outbreaks. Dollar spot can spread by movement of mowers, equipment, water, wind, and people. It has a very wide range of activity. It is most active in temperatures between 60-90 degrees but can occur as long as nights are over 50 degrees (which has been consistent over the last week).  The wet weather/ and high humidity have created an ideal situation for early season dollar spot. 

Removing the dew and guttation water early in the morning through mowing and dragging will help manage dollar spot. Active dollar spot infections produce a cottony white mycelium mass that is often evident on the turf during the early morning hours, not to be confused with spider webs. Fungicides (DMIs) do very well against dollar spot. Chlorothalonil, propiconazole, fenarimol and others are labeled for dollar spot control. It is important to remember that several site-specific inhibitors have the potential for fungicide resistance. To prevent resistance use a rotation of chemicals and avoid repetitive use.  

 Pictures courtesy of Cody Freeman - Green King Turf
 
Leaf spot is an Ascomycete fungi caused by Bipolaris spp. and/or Dreschslera spp. Cool, wet weather favors the disease. Leaf spot affects all turfgrass species used in the state of Iowa. A majority of the damage recorded so far has been on Kentucky bluegrass lawns and golf course roughs. It can also hit bentgrass, fine and tall fescue, and ryegrass.  

The ecology of leaf spot is prolonged wet periods (10+ hours) alternating with drying. The conditions this spring have been perfect for leaf spot on Kentucky bluegrass. Off-color patches of the turf are the first sign of the disease. The turf on the area may also look like it is dry, even after rainfall. A closer look at the leaf tissue shows elliptical purple spots turning to straw-colored on bluegrass.

Leaf spot is most commonly observed in high N fertility situations, and poor surface and subsurface drainage areas. There are several resistant Kentucky bluegrass cultivars in blends or mixtures and this is one of the main reasons it only affects certain areas of the turf.Fungicides are a last resort and generally not recommended on Kentucky bluegrass lawns or low maintenance areas of golf courses. If control is necessary, thiophanates, most QoI (Strobilurins), and chloronitriles provide the best means of control. 

 Pictures courtesy of Cody Freeman - Green King Turf


Friday, March 27, 2015

HERE IS ANOTHER 'NOT QUITE SO OLD' TURF PHOTO

Nick Christians
March 27, 2015
nchris@iastate.edu

Here is another photo from the history file. 

The caption says that it includes Mich Twiot, Shawn Emmack, Jeff Oelmann, Bill Greenwell, Brad Peterson, Scott Luke, and Doug Struyk

That is not in order and the list is not complete.  Let me know if you recognize the others.







Wednesday, March 25, 2015

OLD PICTURES FROM PEOPLE IN THE TURF INDUSTRY

Nick Christians
March 25, 2015
nchris@iastate.edu

There are some very old pictures of people involved in the turf industry in the following link.  These were left to me by Ed Cott, who was in turf extension at Iowa State from the late 1940's to the early 80's.  If you recognize any of these people, let them or their family know about the site.






Click on this link to see all of the pictures.

 https://drive.google.com/file/d/0BzSX2eos6s6ha0Fod2F1Sy1xREE/view

Monday, March 16, 2015

CONTROLLING Poa annua IN SPORTS TURF

Nick Christians
March 16, 2014

This article on controlling Poa annua in sports turf appeared in SPORTSTURF magazine in March of 2015.  You can link to the original by going to:  http://read.dmtmag.com/i/460594


Thursday, January 29, 2015

NEW HORTICULTURE VIDEO ON WEB SITE

Nick Christians
January 29, 2013

The Iowa State University Horticulture Department recently completed a new web site.  As part of the web site, there is a new recruiting video on the first page. 

To view the site, go to http://www.hort.iastate.edu/ 



The video is titled

Every green thing we grow is rooted in cardinal and gold

 

Monday, January 5, 2015

HORTICUTLURE 451 OFFERED ONLINE IN SPRING 2015

Nick Christians
nchris@iastate.edu
Jan. 5, 2015

The advanced turf course, Hort 451, will be offered online again this spring.  It is available in a web-based format that can be accessed from anywhere in world.  Those interested should go to:  
http://agonline.iastate.edu/e-course/professional-turfgrass-management
for more information.
It is available for both undergraduate and graduate credit.

(and NO, this is not my high school graduation picture)

Professional Turfgrass Management

Registration Information

Dept Affiliation: 
Horticulture
Credit Hours: 
2
Semester: 
Spring
Start Date / End Date: 
01/12/2015 to 05/08/2015
Prerequisites: 
Hort 351 or permission of instructor
Max Enrollment: 
25
Course Materials: 
Mathematics of Turfgrass Maintenance, Nick Christians ISBN 9780470048450; 4th Ed, 2008 Wiley Fundamentals of Turfgrass Management, Nick Christians ISBN 9780470587317; 4th Ed, 2011 Wiley
HORT 451
Course Description: 
Turfgrass science including the study of (1) specific information on
soil chemistry and soil modification as they relate to the develop-
ment and maintenance of turfgrass areas, (2) specialized manage-
ment practices used in athletic field care, professional lawn care,
and golf course industries, and (3) construction methods for golf
courses and sports fields. Nonmajor graduate credit.
Number of Credits: 
2

Instructor Info

Instructor: 
Nick Christians

Thursday, November 20, 2014

TIM VANLOO ARTICLE IN SPORTSTURF MAGAZINE.



Nick Christians
Nov. 20, 2014


Here is an article by Tim VanLoo, CSFM, sports turf manager for the Iowa State University Athletic Department.  The title is "Environmental Conservations:  One sports turf manager's story".    It appeared in SportsTurf magazine in October 2014.  You can view the article at http://read.dmtmag.com/i/391471/8




 Tim's contact information is:

Tim VanLoo, CSFM
Manager of Athletic Turf and Grounds
Iowa State University
1800 S. 4th Street
Ames, IA 50011
Office: 515-294-7686
Cell: 515-509-8035
Fax: 515-294-0104