Magazine - Tech Notes Issue 10 Microdochium Patch

By Greencast in Consultancy on 22nd Jun 2010 6:00

Microdochium patch, also known as Fusarium Patch is active from late autumn through spring. The pathogen, Microdochium nivale is especially active on Poa annua in areas that are wet and shaded.

Creeping bentgrass (Agrostis stolonifera), Poa pratensis and Lolium perenne are also susceptible but not to the same extent as Poa annua. Additionally, any young, juvenile, or lush turf going into winter is more susceptible than mature stands.

More and more couch and kikuyu on fairways come under attack during this time of year. Disease symptoms normally start on the shaded side of fairways and depending on rainfall through winter will progress further to entire fairways. This is problematic as the scarring lasts the whole winter and will only start to repair in spring when active growth resumes.

Symptoms initially appear as a yellowing of the infected turf area that progresses rapidly to a rusty, reddish, brown color. The disease progresses producing circular patches that appear tan or whitish with - in some cases - a pinkish border. These patches can range in size from several centimeters to ½ meter in diameter; with patches eventually coalescing into large blighted areas.

The disease is active under cool wet conditions when temperatures range from 0 and 15 C. Given this range, the disease can occur from late autumn through mid-spring. In late winter or early spring when abundant moisture is present, the pathogen spores can be spread along drainage patterns, and easily moved by mowers producing a streaking pattern.

The best way to control disease progression is to apply an effective fungicide at the first signs of disease to the shaded half of the fairway. Repeat as neccessary through winter. Preventative treatment of these areas starting in early to late April has proved very successfull in Sydney over the last few winters.

Photographs

From left to right: 1) Classic symptoms of Microdochium patch on creeping bentgrass. 2) Heavy spore populations of Microdochium nivale can result in streaking symptoms. 3) Microdochium nivale spores



Head to the Greencast website to keep up to date with all things Syngenta.
www.greencast.com.au

For more information email syngenta.info@syngenta.com or freecall 1800 067 108

Read more articles in Consultancy, by Greencast or from June 2010.