Disease Happenings - 2010

Archive of Disease Happenings 2007, 2008, 2009

June 2010

Gray leaf spot is active on St. Augustinegrass lawns and sod farms. Be on the lookout for this disease to worsen with regular return of summer afternoon rains. Lawn areas with shade stress and areas that tend to recieve excess nitrogen fertilizer will have gray leaf spot first and more severe than other parts of the lawn.

Leaf and sheath spot caused by Rhizoctonia zeae has been diagnosed by Jerry on several samples in the first two weeks of June. The disease results in thin turfgrass canopies on bermudagrass and seashore paspalum greens. Symptoms are easily confused with nematode damage, drought stress, and many other stresses. Early diagnosis and management steps can help turfgrass managers get a handle on the problem in the preventative or early curative stage. Fungicide products do a better job preventatively with this disease.

Take all root rot and Bermudagrass decline are starting to progress from the yellowing and thinning symptoms to the patch symptoms at this time of year. We are nearing the end of the window when fungicides can be expected to provide good control of these diseases. Curative applications don't usually do well. Applications at the time of sod installation and 30 days later seem to give the most consistent result, especially in areas where the disease has been a problem before. Don't make applications to soil prior to intalling the new sod. It's a waste of time and money. Apply products to the new sod as soon after installation as possible.

Jan 2010

2009 was another record year for the Rapid Turfgrass Diagnostic Service.

2010 has started with a bang due in part to La Nina weather patterns this winter. Bipolaris leaf spot and melting out are coming into the clinic along with the occasional dollar spot and some large patch, even on the bermudagrass this year. Expect additional disease activity this spring from large patch and take all root rot/Bermudagrass decline.

Mapping Function for Rapid Turf Service

IFAS DDIS folks (thanks Xin) have developed a mapping website for our turf sample data. It shows what diseases occur on what grasses in what FL counties, during time periods the user specifies. Download the plug-in and try it.

Rapid Diagnostics Map

 

• Rapid Turfgrass Diagnostic Service