Search results

Anthracnose basal rot

July 8, 2009

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

Category: 

The Heat is On

June 22, 2010

Summer officially began yesterday although it has felt like summer for some time now. The temperatures forecasted for this week should create ideal conditions for disease activity. Our research facility has a buffet of diseases right now. I have seen red thread, leaf spot, yellow tuft, fairy ring, dollar spot, and brown patch just in the past week. The high stress conditions could also spur on anthracnose. If you think you have anthracnose, look for the black colored fruiting bodies on the leaves of plant. The fruiting bodies, or acervuli, are best viewed using a hand lens or hand held macroscope. More information about identifying anthracnose and management of this disease can be found by clicking here.

A droughty month of May has given way to a wet and rainy June. Weather is the great equalizer in the turf business and this season has been a rollercoaster compared to the steady temperatures we experienced in 2009. Overall, our day and nighttime temperatures have been warmer this year compared to 2009 for the month of June. It was this same time last year that we experienced a warming trend that sent temperatures into the mid 90’s. But so far the biggest difference in weather has been the rainfall. Twenty days into June last year, Ames had received 1.95 inches of rain compared to the 6.36 inches of rain we have gotten this year.

Golf fans saw Irish golfer Graeme McDowell win the 110th U.S. Open on Sunday by shooting even par over four rounds at Pebble Beach. Coming into this tournament I had no idea who Graeme McDowell was but I quickly gained respect for him when listening to his post round interview. While reflecting on what he had just accomplished, and in amongst his numerous thank-yous, he took time to thank the maintenance staff for all their hard work and commented on the great condition of the course. Classy move Mr. McDowell, now off to Disney World you go!

Marcus Jones
Graduate Research Assistant

Category: